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Prof. Dr. S. Backert

Research areas: Host/pathogen interaction

Stable adhesion complexes are crucial for maintenance of the cell-to-cell integrity in healthy epithelia of humans and represent the first barrier for microbial pathogens. Alterations in these complexes are key events in the development and progression of many diseases including various cancers. One of the major proteins involved in maintaining epithelial adhesion is the tumor-suppressor and junctional transmembrane protein E-cadherin. E-cadherin also controls the transcription factor b-catenin and other signaling components, and is involved in cell morphogenesis, adhesion, recognition and communication. Inactivation of E-cadherin’s adhesive properties is often a key step in various infections, tumor progression and metastasis. We have recently identified a novel secreted effector protein, the serine protease HtrA, ofthe foodborne pathogen Campylobacter jejuni and the gastric pathogen and type-I carcinogen Helicobacter pylori. HtrA of these microbes can be secreted into the extracellular space where it can cleave-off the extracellular domain of E-cadherin on polarized gastric or intestinal epithelial cells. Since the htrA gene is conserved in many bacterial pathogens our findings could provide a potential novel mechanism how these microbes may destroy cellular junctions in mucosal epithelial cells, in order to get access to deeper tissues and cause disease by degrading E-cadherin and probably other cellular factors. This project is therefore designed to contribute to the understanding of mechanisms underlying basic HtrA functions in bacterial pathogenesis. In particular, we investigate the molecular mechanisms/requirements for HtrA proteolytic activity, pinpoint novel HtrA targets on host cells and to study downstream signaling events. In addition, we aim to identify the secretion pathway of HtrA across the two bacterial membranes because this could give hints how HtrA is transported. Our studies will take advantage of powerful technologies including fluorescence microscopy and live cell imaging as well as proteomics-based and cellular signal transduction approaches.

Helicobacter pylori is a highly successful pathogen uniquely adapted to colonize humans. Gastric infections with this bacterium can induce pathology ranging from chronic gastritis and peptic ulcers to gastric cancer. More virulent H. pylori isolates harbour numerous well-known adhesins (BabA/B, SabA, AlpA/B, OipA and HopZ) and the cag (cytotoxin-associated genes) pathogenicity island (PAI) encoding a type IV secretion system (T4SS). The adhesins establish tight bacterial contact with host target cells and the T4SS represents a needle-like pilus device for the delivery of effector proteins into host target cells such as CagA. BabA and SabA can bind to blood group antigen and sialylated proteins respectively, and a series of T4SS components including CagI, CagL, CagY and CagA have been shown to target the integrin β1 receptor followed by injection of CagA across the host cell membrane. The interaction of CagA with membrane-anchored phosphatidylserine may also play a role in the delivery process. While substantial progress has been made in our current understanding of many of the above factors, the host cell receptors for OipA, HopZ and AlpA/B during infection are still unknown. We are interested in characterizing the interactions of the various adhesins and structural T4SS proteins with host cell factors. Of particular interest is the T4SS encoded by the cagPAI. T4SSs are macromolecular assemblies used by numerous bacteria to transport molecules across their membranes including proteins and DNA. T4SS are generally composed of a set of 12 proteins (VirB1-11 and the VirD4 coupling factor) plus some accessory proteins. This together represents a dynamic membrane-anchored machinery powered by three encoded NTPases. Since T4SSs are widespread in many pathogenic bacteria where they are often used to deliver effectors into host cells, we investigate the unique and complex interaction of various components of the H. pylori T4SS as a model system. Its interaction with the integrin β1 receptor will help to better understand the molecular mechanisms of how protein translocation events work in H. pylori. We therefore use specific bacterial mutant strains, proteomics-based methods, protein-protein interaction studies such as Biacore and sophisticated microscopic technologies.

As Helicobacter pylori was the first bacterium cultivated from human gastric biopsy specimens in 1982, it has become apparent that Helicobacter subspecies exhibit a broad host spectrum and can be isolated from the gastrointestinal tracts of humans, non-human primates, cats, dogs, cheetahs, ferrets, rodents, cows, sheep, pigs, dolphins, and birds. Currently there are 32 validated Helicobacter species and several other described isolated candidates. Members of the genus Helicobacter are helical curved, spiral or fusiform, Gram-negative bacteria with or without helical periplasmic fibers. We are interested in the investigation and characterization of novel enterohepatic Helicobacter subspecies (EHS), which are an emerging group of microaerobic, motile pathogens carrying flagella with variable styles in number and locations. EHS are known to persistently colonize multiple animal species. They can be isolated from the lower intestine, hepatobiliary system, and diarrheic feces and are potentially associated with chronic inflammation and epithelial cell hyperproliferation leading to neoplasic disease. Helicobacter hepaticus, considered the prototype of all known EHS, has been shown to induce chronic active hepatitis and hepatocellular carcinoma in A⁄JCr and B6C3F1 mice strains as well as typhlocolitis in A⁄JCr inbred mice. This species is also used experimentally to induce cholesterol gallstones, inflammatory bowel disease (IBD), and in certain strains of mice induces colon cancer. Because lesions caused by EHS in mice often mimic those seen in humans with cholecystitis, their possible role in hepatobiliary disease in humans has been proposed. In addition, the possible zoonotic origin of important clinical manifestations in humans and the health status of mice housed in research facilities have recently attracted the attention of scientists. In contrast to H. pylori, almost nothing is known about potential virulence factors in EHS. To evaluate the prevalence of EHS infections in mouse strains harbored in specific-pathogen-free (SPF) facilities, we tested 40 mouse lines that were permanently living in nine colony rooms using a group-specific PCR, which detects all Helicobacter species currently known. When Helicobacter-negative and infected mice shared the same cage, transmission of the infection occurred within two weeks at very high frequency (100%). Furthermore, we found that mice from commercial breeding facilities may carry undetected Helicobacter infections. We also showed that infection with EHS may occur and spread frequently in mice under SPF conditions, and despite extensive safety conditions. Due to the lack of available methods, EHS infections often remain unrecognized but can cause severe health complications or more subtle host immune perturbations and therefore can confound the results of animal experiments. We therefore isolate and investigate live pathogens, and develop methods to rapidly identify novel EHS.

Publications

I Original papers

1.) Backert, S., Dörfel, P., Börner, T. (1995)
Investigation of plant organellar DNAs by pulsed-field gel electrophoresis. Current Genetics 28: 390-399.DOI:10.1007/bf00326439

2.) Backert, S., Lurz, R., Börner, T. (1996)
Electron microscopic investigation of mitochondrial DNA from Chenopodium album (L.). Current Genetics 29: 427-436. DOI:10.1007/bf02221510

3.) Backert, S., Dörfel, P., Lurz, R., Börner, T. (1996)
Rolling circle replication of mitochondrial DNA in the higher plant Chenopodium album (L.). Molecular and Cellular Biology 16: 6285-6294. DOI:10.1128/mcb.16.11.6285

4.) Backert, S., Meißner, K., Börner, T. (1997)
Unique features of the mitochondrial rolling circle-plasmid mp1 from the higher plant Chenopodium album (L.). Nucleic Acids Research 25: 582-589. DOI:10.1093/nar/25.3.582

5.) Backert, S., Lurz, R., Oyarzabal, O.A., Börner, T. (1997)
High content, size and distribution of single-stranded DNA in the mitochondria of Chenopodium album (L.). Plant Molecular Biology 33: 1037-1050. DOI:10.1023/a:1005791310886

6.) Backert, S., Dörfel, P., Börner, T. (1997)
Investigation of plant organellar DNA by pulsed-field gel electrophoresis, Tobacco Abstracts 84: 96-97.

7.) Oyarzabal, O.A., Wesley, L.V., Harmon, K.M., Tucker, L., Barbaree, J.M., Lauerman, L.H.,  Backert, S., Conner, D.E. (1997)
Specific identification of Campylobacter fetus by PCR targeting variable regions of the 16S rRNA. Journal of Veterinary Microbiology 58: 61-71. DOI:10.1016/s0378-1135(97)00148-x

8.) Scissum-Gunn, D.K., Gandhi, M., Backert, S., Nielsen, B.L. (1998)
Separation of different conformations of plant mitochondrial DNA molecules by field inversion gel electrophoresis. Plant Molecular Biology Reporter 16: 219-229. https://doi.org/10.1023/A:1007512108373

9.) Gandhi, M., Hammett, L., Scissum-Gunn, K., Backert, S., Nielsen, B.L. (1998)
Analysis of genome structure and gene copy number in Brassica campestris mitochondrial DNA. FASEB Journal 12(8), Supplement S: A1355

10.) Backert, S., Kunnimalaiyaan, M., Börner, T., Nielsen, B.L. (1998)
In vitro replication of mitochondrial plasmid mp1 from the higher plant Chenopodium album (L.): A remnant of bacterial rolling circle and conjugative plasmids? Journal of Molecular Biology 284: 1005-1015. DOI:10.1006/jmbi.1998.2254

11.) Backert, S., von Nickisch-Rosenegk, E., Meyer, T.F. (1998)
Potential role of two Helicobacter pylori relaxases in DNA transfer? Molecular Microbiology 30: 673-674. DOI:10.1046/j.1365-2958.1998.01086.x

12.) Gratchev, A., Böhm, C., Riede, E., Foss H.D., Hummel, M., Mann, B., Backert, S.,
Buhr, H.J., Stein, H., Riecken, E.-O., Hanski, C. (1998)
Regulation of mucin MUC2 gene expression during colon carcinogenesis. Annals of the New York Academy of Sciences 859: 180-183. DOI:10.1111/j.1749-6632.1998.tb11122.x

13.) Gelos, M., Backert, S., Klussmann, E., Gratchev, A., Kobalz, U., Mann, B., Moyer, M.P., Böhm, C., Riecken, E.O., Hanski, C. (1998)
Detection of differential gene expression in colorectal cancer cell lines: comparison of three methods. Journal of Molecular Medicine 76(6): B13.

14.) Backert, S., Gelos, M., Kobalz, U., Hanski, M.L., Böhm, C., Mann, B., Lövin, N.,
Gratchev, A., Mansmann, U., Moyer, M.P., Riecken, E.O., Hanski, C. (1999)
Differential gene expression in colon carcinoma cells and tissues detected with a cDNA array. International Journal of Cancer 82: 868-874. DOI:10.1002/(sici)1097-0215(19990909)82:6<868::aid-ijc16>3.0.co;2-w

15.) Backert, S., Börner, T. (2000)
Phage T4-like intermediates of DNA replication and recombination in the mitochondria of the higher plant Chenopodium album (L.). Current Genetics 37: 304-314. DOI:10.1007/s002940050532

16.) Backert, S., Ziska, E., Brinkmann, V., Zimny-Arndt, U., Fauconnier, A., Jungblut, P.R., Naumann, M., Meyer, T.F. (2000)
Translocation of the Helicobacter pylori CagA protein in gastric epithelial cells by a type IV secretion apparatus. Cellular Microbiology 2: 155-164. DOI:10.1046/j.1462-5822.2000.00043.x

17.) Backert, S. (2000)
Strand-switching during rolling circle replication of plasmid-like DNA minicircles in the mitochondria of the higher plant Chenopodium album (L.). Plasmid 43: 166-170. DOI:10.1006/plas.1999.1437

18.) Ramarao, N., Gray-Owen, S.D., Backert, S., Meyer, T.F. (2000)
Helicobacter pylori inhibits phagocytosis by professional phagocytes involving type IV secretion components. Molecular Microbiology 37: 1389-1404. DOI:10.1046/j.1365-2958.2000.02089.x

19.) Backert, S., Müller, E.-C., Jungblut, P.R., Meyer, T.F. (2001)
Tyrosine phosphorylation patterns and size modification of the Helicobacter pylori CagA protein after translocation into gastric epithelial cells. Proteomics 1: 608-617. DOI:10.1002/1615-9861(200104)1:4<608::AID-PROT608>3.0.CO;2-G

20.) Moese, S., Selbach, M., Zimny-Arndt, U., Jungblut, P.R., Meyer, T.F., Backert, S. (2001)
Identification of a tyrosine-phosphorylated 35 kDa carboxy-terminal fragment (p35CagA) of the Helicobacter CagA protein in phagocytic cells: Processing or breakage? Proteomics 1: 618-629. DOI:10.1002/1615-9861(200104)1:4<618::AID-PROT618>3.0.CO;2-C

21.) Backert, S., Moese, S., Selbach, M., Brinkmann V,  Meyer, T.F. (2001)
Phosphorylation of tyrosine 972 of the Helicobacter pylori CagA protein is essential for induction of a scattering phenotype in gastric epithelial cells. Molecular Microbiology 42: 631-644. DOI:10.1046/j.1365-2958.2001.02649.x

22.) Kwok, T., Backert, S., Schwarz, H., Berger, J., Meyer, T.F. (2002)
Specific entry of Helicobacter pylori into cultured gastric epithelial cells via a zipper-like mechanism. Infection & Immunity 70, 2108-2120. DOI:10.1128/iai.70.4.2108-2120.2002

23.) Selbach, M., Moese, S., Meyer, T.F., Backert, S. (2002)
Functional analysis of the Helicobacter pylori cag pathogenicity island reveals both VirD4/CagA-dependent and VirD4/CagA-independent mechanisms. Infection & Immunity 70: 665-671. DOI:10.1128/iai.70.2.665-671.2002

24.) Selbach, M., Moese, S., Hauck, C.R., Meyer, T.F., Backert, S. (2002)
Src is the kinase of the Helicobacter pylori CagA protein in vivo and in vitro. Journal of Biological Chemistry 277: 6775-6778. DOI:10.1074/jbc.C100754200

25.) Moese, S., Selbach, M., Meyer, T.F., Backert, S. (2002)
cag+ Helicobacter pylori induce a homotypic aggregation phenotype in macrophage-like cells by upregulation and recruitment of intracellular adhesion molecule 1 to the cell surface. Infection & Immunity 70: 4687-4691. DOI:10.1128/iai.70.8.4687-4691.2002

26.) Backert, S. (2002)
R-loop dependent rolling-circle replication and a new model for DNA concatemer resolution by mitochondrial plasmid mp1. EMBO Journal 21: 3128-3136.  DOI:10.1093/emboj/cdf311

27.) Selbach, M., Moese, S., Hauck, C.R., Meyer, T.F., Backert, S. (2003)

The Helicobacter pylori CagA protein induces cortactin dephosphorylation and actin rearrangement by c-Src inactivation. EMBO Journal 22: 515-528. DOI:10.1093/emboj/cdg050

28.) Zawilak, A.,  Durrant, M.C., Jakimowicz, P., Backert, S., Zakrzewska-Czerwińska J. (2003)
DNA binding specificity of the replication initiator protein, DnaA from Helicobacter pylori. Journal of Molecular Biology 334: 933-947. DOI:10.1016/j.jmb.2003.10.018

29.) Backert, S., Schwarz, T., Miehlke, S., Kirsch, C., Sommer, Ch., Kwok, T., Gerhard M., Goebel, U., Lehn, N., König, W., Meyer, T.F. (2004)
Functional analysis of the cag pathogenicity island in Helicobacter pylori isolates from patients with gastritis, peptic ulcer and gastric cancer. Infection & Immunity 72: 1043-1056. DOI:10.1128/iai.72.2.1043-1056.2004

30.) Moese, S., Selbach, M. Kwok, T., Brinkmann, V., König, W., Meyer, T.F. Backert, S. (2004)
Helicobacter pylori induces AGS cell motility and elongation via independent pathways. Infection & Immunity 72: 3646-3649. DOI:10.1128/IAI.72.6.3646-3649.2004

31.) Selbach, M., Moese, S., Backert, S., Jungblut, P.R., Meyer, T.F. (2004)
The Helicobacter pylori CagA protein induces tyrosine dephosphorylation of ezrin. Proteomics 4: 2961-2968. DOI:10.1002/pmic.200400915

32.) Backert, S., Gressmann, H., Kwok, T., Zimmy-Arndt, U., König, W., Jungblut, P.R.; Meyer, T.F. (2005)
Gene expression and protein profiling of AGS gastric epithelial cells upon infection with Helicobacter pylori. Proteomics 5: 3902-3918. DOI:10.1002/pmic.200401240

33.) Backert, S., Kwok, T., Schmid, M., Selbach, M., Moese, S., Peek, R.M. Jr, König, W., Meyer, T.F., Jungblut, P.R. (2005)
Subproteomes of soluble and structure-bound Helicobacter pylori proteins analysed by two-dimensional gel electrophoresis and mass spectrometry. Proteomics 5: 1331-1345. DOI:10.1002/pmic.200401019

34.) Enarsson, K., Brisslert, M., Backert, S., Quiding-Järbrink, M. (2005)
Helicobacter pylori induce transendothelial migration of activated memory T cells. Infection & Immunity 73: 761-769. DOI:10.1128/IAI.73.2.761-769.2005

35.) Brisslert, M., Enarsson, K., Lundin, B.S., Karlsson, A., Kusters J., Svennerholm, A.-M.,
Backert, S., Quiding-Järbrink, M. (2005)
Helicobacter pylori induce neutrophil transendothelial migration: role of the bacterial HP-NAP. FEMS Microbiology Letters 249: 95-103. DOI:10.1016/j.femsle.2005.06.008

36.) Gieseler, S., König, B., König, W., Backert, S. (2005)
Strain-specific expression profiles of virulence genes in Helicobacter pylori during infection of gastric epithelial cells and granulocytes. Microbes & Infection 7: 437-447. DOI:10.1016/j.micinf.2004.11.018

37.) Backert, S., Kwok, T., König, W. (2005)
Conjugative plasmid DNA transfer in Helicobacter pylori mediated by chromosomally encoded relaxase and TraG-like proteins. Microbiology 151(Pt 11): 3493-3503. DOI:10.1099/mic.0.28250-0

38.) Brandt, S., Kwok, T., Hartig, R., König, W., Backert, S. (2005)
NF-kB-activation and potentiation of proinflammatory responses by the Helicobacter pylori CagA protein. Proceedings of the National Academy of Sciences USA 102: 9200-9205. DOI:10.1073/pnas.0409873102

39.) Dossumbekova, A., Prinz, C., Gerhard, M., Brenner, L., Backert, S., Kusters, J.G.,
Schmid, R.M., Rad, R. (2006)
Helicobacter pylori outer membrane proteins and gastric inflammation. Gut 55: 1360-1361.

40.) Dossumbekova, A., Prinz, C., Mages, J., Lang, R., Kusters, J.G., vanVliet, A.H., Reindl, W., Backert, S., Saur, D., Schmid, R.M., Rad, R. (2006)
Helicobacter pylori HopH (OipA) and bacterial pathogenicity: genetic and functional genomic analysis of hopH gene polymorphisms. Journal of Infectious Diseases 194:1346-1355. DOI:10.1086/508426

41.) Backert, S. (2006)
Interaction of Helicobacter pylori with its host: role of the cag pathogenicity island and multiple functions of the CagA protein. European Journal of Cell Biology 85 (Suppl.): 117-118.

42.) Bohr, U.R.M., Selgrad, M., Ochman, C., Backert, S., König, W., Fenske, A., Wex, T.,
Malfertheimer, P. (2006)
Prevalence and spread of enterohepatic Helicobacter in mice reared in a specific pathogen-free facility. Journal of Clinical Microbiology 44, 738-742. DOI:10.1128/JCM.44.3.738-742.2006

43.) Krause-Gruszczynska, M., Rohde, M., Hartig, R., Genth, H., Schmidt, G., Keo, T., König, W., Miller, W.G., Konkel, M.E., Backert, S. (2007)
Role of the small Rho GTPases Rac1 and Cdc42 in host cell invasion of Campylobacter jejuni. Cellular Microbiology 9: 2431-2444. DOI:10.1111/j.1462-5822.2007.00971.x

44.) Krause-Gruszczynska, M., van Alphen, L.B., Oyarzabal, O.A., Alter, T. Hänel, I., Schliephake, A., König, W.,van Putten, J., Konkel, M.E., Backert, S. (2007)
Expression Patterns and Role of the CadF protein in Campylobacter jejuni and Campylobacter coli. FEMS Microbiology Letters 274: 9-16. DOI:10.1111/j.1574-6968.2007.00802.x

45.) Oyarzabal, O.A., Rad, R., Backert, S. (2007)
Conjugative Transfer of Chromosomally-Encoded Antibiotic Resistance from Helicobacter pylori to Campylobacter jejuni. Journal of Clinical Microbiology 45: 402-408. DOI:10.1128/JCM.01456-06

46.) Oyarzabal, O.A., Backert, S., Nagaraj, M., Miller, R.S., Hussain, K.S., Oyarzabal, E.A. (2007)
Efficacy of Supplemented Buffered Peptone Water for the Isolation of Campylobacter jejuni and C. coli from Broiler Retail Products. Journal of Microbiological Methods 69: 129-136. DOI:10.1016/j.mimet.2006.12.011

47.) Brandt, S., Shafikhani, S., Balachandran, P., Jin, S., Hartig R., König, W., Engel, J., Backert, S. (2007)
Use of a novel co-infection system reveals a role for Rac1, H-Ras, and CrkII phosphorylation in Helicobacter pylori-induced host cell actin cytoskeletal rearrangements. FEMS Immunology and Microbiology 50: 190-205. DOI:10.1111/j.1574-695X.2007.00234.x

48.) Blumenthal, B., Hoffmann, C., Aktories, K., Backert, S., Schmidt, G. (2007)
The Cytotoxic Necrotizing Factors from Yersinia pseudotuberculosis and from Escherichia coli Bind to Different Cellular Receptors but Take the Same Route to the Cytosol. Infection & Immunity 75: 3344-3353. DOI:10.1128/IAI.01937-06

49.) Moese, S., Selbach, M., Brinkmann, V., Karlas, A., Haimovich, B., Backert, S., Meyer, T.F. (2007)
The Helicobacter pylori CagA protein disrupts matrix adhesion of gastric epithelial cells by dephosphorylation of vinculin. Cellular Microbiology 9: 1148-1161. DOI:10.1111/j.1462-5822.2006.00856.x

50.) Tammer, I., Brandt, S., Hartig, R., König, W., Backert, S. (2007)
Activation of c-Abl by Helicobacter pylori: a novel kinase for CagA and crucial mediator of host cell scattering. Gastroenterology 132: 1309-1319. DOI:10.1053/j.gastro.2007.01.050

51.) Potturi-Venkata, L.P., Backert, S., Vieira, S.L., Oyarzabal, O.A. (2007)
Evaluation of logistic processing to reduce cross-contamination of commercial broiler carcasses with Campylobacter spp. Journal of Food Protection 70: 2549- 2554. DOI:10.4315/0362-028x-70.11.2549

52.) Kwok, T., Zabler, D., Urman, S., Rohde, M., Hartig, R., Wessler, S., Misselwitz, R., Berger, J., Sewald, N., König, W., Backert, S. (2007)
Helicobacter exploits integrin for type IV secretion and kinase activation. Nature 449: 862-866. DOI:10.1038/nature06187

53.) Potturi-Venkata, L.P., Backert, S., Lastovica, A.J., Vieira, S.L., Norton, R.A., Miller, R.S., Pierce, S., Oyarzabal, O.A. (2007)
Evaluation of different plate media for direct cultivation of Campylobacter species from live broilers. Poultry Science 86: 1304-1311. DOI:10.1093/ps/86.7.1304

54.) Knauer, O., Binai, N.A., Carra, G., Beckhaus, T., Hanschmann, K.M., Renné, T., Backert, S., Karas, M., Wessler, S. (2008)
Differential phosphoproteome profiling reveals a functional role for VASP in Helicobacter pylori-induced cytoskeleton turnover in gastric epithelial cells. Cellular Microbiology 10: 2285-2296. DOI:10.1111/j.1462-5822.2008.01207.x

55.) Oyarzabal, O.A., Backert, S., Williams, L.L., Lastovica, A.J., Miller, R.S., Pierce, S.J., Vieira, S.L., Rebollo-Carrato, F. (2008)
Molecular typing, serotyping and cytotoxicity testing of Campylobacter jejuni strains isolated from commercial broilers in Puerto Rico. Journal of Applied Microbiology 105: 800-812. DOI:10.1111/j.1365-2672.2008.03809.x

56.) Speegle, L., Miller, M.E., Backert, S., Oyarzabal, O.A. (2009)
Use of cellulose filters to isolate Campylobacter spp. from naturally contaminated retail broiler meat. Journal of Food Protection 72: 2592-2596. DOI:10.4315/0362-028x-72.12.2592

57.) Tegtmeyer, N., Backert, S. (2009)
Bacterial type III effectors inhibit cell lifting by targeting integrin-linked kinase. CELL host & microbe 5: 514-516. DOI:10.1016/j.chom.2009.06.001

58.) Brandt, S., Kenny, B., Rohde, M., Martinez-Quiles, N., Backert, S. (2009)
Dual infection system identifies a crucial role for PKA-mediated serine phosphorylation of the EPEC-Tir-injected effector protein in regulating Rac1 function. Cellular Microbiology 11: 1254-1271. DOI:10.1111/j.1462-5822.2009.01330.x

59.) Brandt, S., Wessler, S., Hartig, R., Backert, S. (2009)
Helicobacter pylori activates protein kinase C delta to control Raf in MAP kinase signalling: role in AGS epithelial cell scattering and elongation. Cell Motility and the Cytoskeleton 66: 874-892. DOI:10.1002/cm.20373

60.) Svensson, H., Hansson, M., Kilhamn, J., Backert, S., Quiding-Järbrink, M. (2009)
Selective upregulation of endothelial E-selectin in response to Helicobacter pylori-induced gastritis. Infection and Immunity 77: 3109-3116. DOI:10.1128/IAI.01460-08

61.) Selbach, M., Paul, F.E., Brandt, S., Guye, P., Daumke, O., Backert, S., Dehio, C., Mann, M. (2009)
Host cell interactome of tyrosine-phosphorylated bacterial proteins. CELL host & microbe 5: 397-403. DOI:10.1016/j.chom.2009.03.004

62.) Tegtmeyer, N., Zabler, D., Schmidt, D., Hartig, R., Brandt, S., Backert, S. (2009)
Importance of EGF receptor, HER2/Neu and Erk1/2 kinase signalling for host cell elongation and scattering induced by the Helicobacter pylori CagA protein: antagonistic effects of the vacuolating cytotoxin VacA. Cellular Microbiology 11: 488-505. DOI:10.1111/j.1462-5822.2008.01269.x

63.) Sason, H., Milgrom, M., Weiss, A.M., Melamed-Book, N., Balla, T., Grinstein, S., Backert, S., Rosenshine, I., Aroeti, B. (2009)
Enteropathogenic Escherichia coli subverts phosphatidylinositol 4,5-bisphosphate and phosphatidylinositol 3,4,5-trisphosphate upon epithelial cell infection. Molecular Biology of the Cell 20: 544-555. Erratum in: Molecular Biology of the Cell 20: 2638. DOI:10.1091/mbc.e08-05-0516

64.) Manchekar, M., Scissum-Gunn, K.D., Hammett, L.A., Backert, S., Nielsen, B.L. (2009)
Mitochondrial DNA recombination in Brassica campestris. Plant Science 177: 629-635. https://doi.org/10.1016/j.plantsci.2009.08.002

65.) Olofsson, A., Vallström, A., Petzold, K., Tegtmeyer, N., Schleucher, J., Carlsson, S., Haas, R., Backert, S., Wai, S.N., Gröbner, G., Arnqvist, A. (2010) Biochemical and functional characterization of Helicobacter pylori vesicles. Molecular Microbiology 77: 1539-1555. DOI:10.1111/j.1365-2958.2010.07307.x

66.) Backert, S., Tegtmeyer, N., Selbach, M. (2010)
The versatility of Helicobacter pylori CagA effector protein functions: The master key hypothesis. Helicobacter 15: 163-176. DOI:10.1111/j.1523-5378.2010.00759.x

67.) Tegtmeyer, N., Hartig, R., Delahay, R.M., Rohde, M., Brandt, S., Conradi, J., Takahashi, S., Smolka, A.J., Sewald, N., Backert, S. (2010)
A small fibronectin-mimicking protein from bacteria induces cell spreading and focal adhesion formation. Journal of Biological Chemistry 285: 23515-23526. DOI:10.1074/jbc.M109.096214

68.) Saha, A., Backert, S., Hammond, C.E., Gooz, M., Smolka, A.J. (2010)
Helicobacter pylori CagL activates ADAM17 to induce repression of the gastric H, K-ATPase alpha subunit. Gastroenterology 139: 239-248. DOI:10.1053/j.gastro.2010.03.036

69.) Hoy, B., Löwer, M., Weydig, C., Carra, G., Tegtmeyer, N., Geppert, T.,Schröder, P.,  Sewald, N., Backert, S., Schneider, G., Wessler, S. (2010)
Helicobacter pylori HtrA is a new secreted virulence factor that cleaves E-Cadherin to disrupt intercellular adhesion. EMBO Reports 11: 798-804. DOI:10.1038/embor.2010.114

70.) Rivas Traverso, F., Bohr, U.R.M., Oyarzabal, O.A., Rohde, M., Clarici, A., Wex, T., Kuester, D., Malfertheiner, P., Fox, J.G., Backert, S. (2010)
Morphologic, genetic and biochemical characterization of Helicobacter magdeburgensis, a novel species isolated from the intestine of laboratory mice. Helicobacter 15:403-415. DOI:10.1111/j.1523-5378.2010.00770.x

71.) Kumar Pachathundikandi, S., Brandt, S., Madassery, J., Backert, S. (2011)
Induction of TTLR-2 and TLR-5 expression by Helicobacter pylori switches cagPAI-dependent signalling leading to the secretion of IL-8 and TNF-α. PLosOne 6:e19614.  DOI:10.1371/journal.pone.0019614. Erratum in: Plos One 10: e0141721. DOI:10.1371/journal.pone.0141721

 

72.) Zhou, P., Hussain, S.K., Liles, M.R. Arias, C.R. Backert, S., Kieninger, K., Oyarzabal, O.A. (2011)
A simplified and cost-effective enrichment protocol for the isolation of Campylobacter spp. from retail broiler meat without microaerobic incubation. BMC Microbiology 11:175. DOI:10.1186/1471-2180-11-175

73.) Oelkers, M., Vinzenz, M., Nemethova, M., Jakob, S., Lai, F.P.L., Block, J., Szczodrak, M., Kerkhoff, E., Backert, S., Schlüter, K., Stradal, T.E.B., Small, J.V. Koestler, S., Rottner, K. (2011) Microtubules as platforms for assaying actin polymerization in vivo. PLosOne 6: e19931. DOI:10.1371/journal.pone.0019931

74.) Tegtmeyer, N., Wittelsberger, R., Hartig, R., Martinez-Quiles, N., Backert, S. (2011)
Serine phosphorylation of cortactin controls focal adhesion kinase activity and cell scattering induced by Helicobacter pylori. CELL host & microbe 9: 520-531. DOI:10.1016/j.chom.2011.05.007

75.) Krause-Gruszczynska,, M., Boehm, M., Rohde, M., Tegtmeyer, N., Takahashi, S., Buday, L., Oyarzabal, O.A, Backert, S. (2011)
The signaling pathway of Campylobacter jejuni-induced Cdc42 activation: Role of fibronectin, integrin beta1, tyrosine kinases and guanine exchange factor Vav2. CELL Communication & Signalling 9: 32. DOI:10.1186/1478-811X-9-32

76.) Boehm, M., Krause-Gruszczynska, M., Rohde, M., Tegtmeyer, N., Takahashi, S., Oyarzabal, O.A, Backert, S. (2011)
Major host factors involved in epithelial cell invasion of Campylobacter jejuni: Role of fibronectin, Integrin Beta1, FAK, Tiam-1, and DOCK180 in activating Rho GTPase Rac1. Frontiers in Cellular & Infection Microbiolgy 1: 17. DOI:10.3389/fcimb.2011.00017

77.) Hoy, B., Geppert, T., Reisen, F., Plattner, P., Gadermaier, G., Sewald, N., Ferreira, F., Briza, P., Schneider, G., Backert, S., Wessler, S. (2012)
Distinct roles of HtrA proteases from Gram-negative pathogens in cleaving the junctional protein and tumor suppressor E-cadherin. Journal Biological Chemistry 287: 10115-10120. DOI:10.1074/jbc.C111.333419

78.) Roure, S., Bonis, M., Chaput, C., Ecobichon, Mattox, A., C., Barrière, C., Geldmacher, N., Guadagnini, N., Schmitt, C., Prévost, M.-C., Labigne, A., Backert, S., Ferrero, R.L. Boneca, I.G. (2012)
Peptidoglycan maturation enzymes affect flagellar functionality in bacteria. Molecular Microbiology 86: 845-856. DOI:10.1111/mmi.12019

79.) Conradi, J., Huber, S., Gaus, K., Mertink, F., Royo Gracia, S., Strijowski, U., Backert, S., Sewald, N. (2012)
Cyclic RGD peptides interfere with binding of the Helicobacter pylori protein CagL to integrins V3 and 51. Amino Acids 43: 219-232. DOI:10.1007/s00726-011-1066-0. Erratum in: Mol Microbiol. 2013;88(2):456-457.

80.) Wiedemann, T., Hofbaur, S., Tegtmeyer, N., Huber, S., Sewald, N., Wessler, S., Backert, S., Rieder, G. (2012)
Helicobacter pylori CagL-dependent induction of gastrin expression via a novel αvβ5-integrin-integrin linked kinase signalling complex. Gut 61: 986-996. DOI:10.1136/gutjnl-2011-300525

81.) Mueller, D., Tegtmeyer, N., Brandt, S., Yamaoka, Y., De Poire, E., Sgouras, D., Wessler, S., Torres, J., Smolka, A., Backert, S. (2012)
c-Src and c-Abl kinases control hierarchic phosphorylation and function of the CagA effector protein in Western and East Asian Helicobacter pylori strains. Journal of Clinical Investigation 122: 1553-1566. DOI:10.1172/JCI61143

82.) Boehm, M., Hoy, B., Rohde, M., Tegtmeyer, N., Bæk, K.T., Oyarzabal, O.A., Brøndsted, L., Wessler, S., Backert, S. (2012)
Rapid paracellular transmigration of Campylobacter jejuni across polarized epithelial cells without affecting TER: role of proteolytic-active HtrA cleaving E-cadherin but not fibronectin. Gut Pathogens 25: 3. DOI:10.1186/1757-4749-4-3

83.) Conradi, J., Tegtmeyer, N., Woźna M, Wissbrock M, Michalek C, Gagell C, Cover TL, Frank R, Sewald, N., Backert, S. (2012)
An RGD helper sequence in CagL of Helicobacter pylori assists in interactions with integrins and injection of CagA. Frontiers Cellular Infection Microbiology 2: 70. DOI:10.3389/fcimb.2012.00070

 

84.) Hirsch, C., Tegtmeyer, N., Rohde, M., Rowland, M., Oyarzabal, O.A., Backert, S., (2012)
Live Helicobacter pylori in the root canal of endodontic-infected deciduous teeth. Journal Gastroenterology 47: 936-940. DOI:10.1007/s00535-012-0618-8

 

85.) Tegtmeyer, N., Rivas Traverso, F., Rohde, M., Oyarzabal, O.A., Lehn, N., Berg. D.E.,
Fox, J.G., Backert, S. (2013)
Electron microscopic, genetic and protein expression analysis of a novel Helicobacter acinonychis strains from a Bengal tiger. Plos One 8: e71220. DOI:10.1371/journal.pone.0071220

 

86.) Kim, D.J., Park, J.H., Franchi, L., Backert, S., Núñez, G. (2013)
The Cag pathogenicity island and interaction between TLR2/NOD2 and NLRP3 regulate IL-1β production in Helicobacter pylori infected dendritic cells. European Journal of Immunology 44: 2197. DOI:10.1002/eji.201243281

 

87.) Patel, S.R., Smith, K., Letley, D.P., Cook, K.W., Memon, A.A., Ingram, R.J., Staples
E., Backert, S., Zaitoun, A.M., Atherton, J.C., Robinson, K. (2013)
Helicobacter pylori downregulates expression of human β-defensin 1 in the gastric mucosa in a type IV secretion-dependent fashion. Cellular Microbiology 5: 2080-2092. DOI:10.1111/cmi.12174

 

88.) Barden, S., Lange, S., Tegtmeyer, N., Conradi, J., Sewald, N., Backert, S., Niemann,
H.H. (2013)
A helical RGD motif promoting cell adhesion: crystal structures of the Helicobacter pylori type IV secretion system pilus protein CagL. Structure 21: 1931-1941. DOI:10.1016/j.str.2013.08.018

 

89.) Lind, J., Backert, S., Pfleiderer, K., Berg, D.E., Yamaoka, Y., Sticht, H., Tegtmeyer, N.
(2014)
Systematic analysis of phosphotyrosine antibodies recognizing single phosphorylated EPIYA-motifs in CagA of Western-type Helicobacter pylori strains. PLoS One 9: e96488. DOI:10.1371/journal.pone.0096488

90.) Tegtmeyer, N., Lind, J., Schmid, B., Backert, S. (2014)
Helicobacter pylori CagL Y58/E59 mutation turns-off type IV secretion-dependent delivery of CagA into host cells. PLoS One 9: e97782. DOI:10.1371/journal.pone.0097782

91.) Heimesaat, M.M., Fischer, A., Alutis, M., Grundmann, U., Boehm, M., Tegtmeyer, N.,
Göbel, U.B., Kühl, A.A., Bereswill, S., Backert, S. (2014)
The impact of serine protease HtrA in apoptosis, intestinal immune responses and extra-intestinal histopathology during Campylobacter jejuni infection of infant mice. Gut Pathogens 6: 16. DOI:10.1186/1757-4749-6-16

92.) Heimesaat, M.M., Alutis, M., Grundmann, U., Fischer A, Tegtmeyer N, Böhm M,
Kühl, A.A., Göbel, U.B., Backert, S., Bereswill, S. (2014)
The role of serine protease HtrA in acute ulcerative enterocolitis and extra-intestinal immune responses during Campylobacter jejuni infection of gnotobiotic IL-10 deficient mice. Frontiers in Cellular and Infection Microbiology 4: 77. DOI:10.3389/fcimb.2014.00077

93.) Zhang, Y.M., Noto, J.M., Hammond, C.E., Barth, J.L., Argraves, W.S., Backert, S., Peek, R.M. Jr., Smolka, A.J. (2014)
Helicobacter pylori-induced posttranscriptional regulation of H-K-ATPase α-subunit gene expression by miRNA. American Journal of PhysiologyGastrointestinal and Liver Physiology 306: G606-613. DOI:10.1152/ajpgi.00333.2013

94.) Barden, S., Schomburg, B., Conradi, J., Backert, S., Sewald, N., Niemann, H.H. (2014)
Structure of a three-dimensional domain-swapped dimer of the Helicobacter pylori type IV secretion system pilus protein CagL. Acta Crystallographica Section D: Biological Crystallography 70(Pt 5): 1391-1400. DOI:10.1107/S1399004714003150

95.) Tenguria, S., Ansari, S.A., Khan, N., Ranjan, A., Devi, S., Tegtmeyer, N., Lind, J., Backert, S., Ahmed, N. (2014)
Helicobacter pylori cell translocating kinase (CtkA/JHP0940) is pro-apoptotic in mouse macrophages and acts as auto-phosphorylating tyrosine kinase. International Journal of Medical Microbiology 304: 1066-1076. DOI:10.1016/j.ijmm.2014.07.017

96.) Zhang, X.S., Tegtmeyer, N., Traube, L., Jindal, S., Perez-Perez, G., Sticht, H., Backert, S., Blaser, M.J. (2015)
A Specific A/T Polymorphism in Western Tyrosine Phosphorylation B-Motifs Regulates Helicobacter pylori CagA Epithelial Cell Interactions. PLoS Pathogens 11: e1004621. DOI:10.1371/journal.ppat.1004621

97.) Boehm, M., Lind, J., Backert, S., Tegtmeyer, N. (2015)
Campylobacter jejuni serine protease HtrA plays an important role in heat tolerance, oxygen resistance, host cell adhesion, invasion, and transmigration. European Journal of Microbiology and Immunology 5: 68-80. DOI:10.1556/EUJMI-D-15-00003

98.) Koch, K.N., Hartung, M.L., Urban, S., Kyburz, A., Bahlmann, A.S., Lind, J., Backert,
S., Taube, C., Müller, A. (2015)
Helicobacter urease-induced activation of the TLR2/NLRP3/IL-18 axis protects against asthma. The Journal of Clinical Investigation 125: 3297-3302. DOI:10.1172/JCI79337

99.) Perna, A.M., Rodrigues, T., Schmidt, T.P., Böhm, M., Stutz, K., Reker, D., Pfeiffer, B.,
Altmann, K.H., Backert, S., Wessler, S., Schneider, G. (2015)
Fragment-Based De Novo Design Reveals a Small-Molecule Inhibitor of Helicobacter pylori HtrA. Angewandte Chemie International Edition in English 54: 10244-10248. DOI:10.1002/anie.201504035

100.) Hammond, C.E., Beeson, C., Suarez, G., Peek, R.M. Jr., Backert, S., Smolka, A.J.
(2015)
Helicobacter pylori virulence factors affecting gastric proton pump expression and acid secretion. American Journal of Physiology-Gastrointestinal and Liver Physiology 309: G193-201. DOI:10.1152/ajpgi.00099.2015

101.) Hartung, M.L., Gruber, D.C., Koch, K.N., Grüter, L., Rehrauer, H., Tegtmeyer, N., Backert, S., Müller, A. (2015)
H. pylori-induced DNA strand breaks are introduced by nucleotide excision repair endonucleases and promote NF-kB target gene expression. Cell Reports 13: 70-79. DOI:10.1016/j.celrep.2015.08.074

102.) Lind, J., Backert, S., Hoffmann, R., Eichler, J., Yamaoka, Y., Perez-Perez, G.I., Torres, J., Sticht, H., Tegtmeyer, N. (2016)
Systematic analysis of phosphotyrosine antibodies recognizing single phosphorylated EPIYA-motifs in CagA of East Asian-type Helicobacter pylori strains. BMC Microbiology 16: 201. DOI:10.1186/s12866-016-0820-6

103.) Tegtmeyer, N., Moodley, Y., Yamaoka, Y., Pernitzsch, S.R., Schmidt, V., Rivas Traverso, F., Schmidt, T.P., Rad, R., Yeoh, K.G., Bow, H., Torres, J., Gerhard, M., Schneider, G., Wessler, S., Backert, S. (2016)
Characterization of worldwide Helicobacter pylori strains reveals genetic conservation and essentiality of serine protease HtrA. Molecular Microbiology 99: 925-944. DOI:10.1111/mmi.13276

104.) Pachathundikandi, S.K., Backert, S. (2016)
Differential expression of Interleukin 1β during Helicobacter pylori infection of Toll-like receptor 2 (TLR2) and TLR10-expressing HEK293 cell lines. The Journal of Infectious Diseases 214: 166-167. DOI:10.1093/infdis/jiw154

105.) Schmidt, T.P., Perna, A.M., Fugmann, T., Böhm, M., Hiss, J., Haller, S., Götz, C., Tegtmeyer, N., Hoy, B., Rau, T.T., Neri, D., Backert, S., Schneider, G., Wessler, S. (2016)
Identification of E-cadherin signature motifs functioning as cleavage sites for Helicobacter pylori HtrA. Scientific Reports 6: 23264. DOI:10.1038/srep23264

106.) Javaheri, A., Kruse, T., Moonen,s K., Mejías-Luque, R., Debraekeleer, A., Asche, C.I., Tegtmeyer, N., Kalali, B., Bach, N.C., Sieber, S.A., Hill, D.J., Königer, V., Hauck, C.R., Moskalenko, R., Haas, R., Busch, D.H., Klaile, E., Slevogt H., Schmidt, A., Backert, S., Remaut, H., Singer, B.B., Gerhard, M. (2016)
Helicobacter pylori adhesin HopQ engages in a virulence-enhancing interaction with human CEACAMs. Nature Microbiology 2: 16189. DOI:10.1038/nmicrobiol.2016.189. Erratum in: Nat Microbiol. 2: 16243. DOI:10.1038/nmicrobiol.2016.243

107.) Lim, M.C.C., Maubach, G., Sokolova, O., Feige, M.H., Diezko, R., Buchbinder, J., Backert, S., Schlüter, D., Lavrik, I.N., Naumann, M. (2017)
Pathogen-induced ubiquitin-editing enzyme A20 bifunctionally shuts off NF-κB and caspase-8-dependent apoptotic cell death. Cell Death Differentiation 24: 1621-1631. DOI:10.1038/cdd.2017.89

108.) Harrer, A., Boehm, M., Backert, S., Tegtmeyer, N. (2017)
Overexpression of serine protease HtrA enhances disruption of adherens junctions, paracellular transmigration and type IV secretion of CagA by Helicobacter pylori. Gut Pathogens 9: 40.DOI:10.1186/s13099-017-0189-6

109.) Boehm, M., Tegtmeyer, N., Harrer, A., Skórko-Glonek, J., Backert, S. (2017)
Expression of Helicobacter pylori serine protease HtrA in Campylobacter jejuni reveals a crucial function in oxygen stress resistance, heat tolerance and epithelial barrier disruption. Journal of Cellular Immunology and Serum Biology 3: 105- 114. https://doi.org/10.15436/2471-5891.17.009

110.) Tegtmeyer, N., Wessler, S., Necchi, V., Rohde, M., Harrer, A., Rau, T.T., Asche, C.I., Boehm, M., Loessner, H., Figueiredo, C., Naumann, M., Palmisano, R., Solcia, E., Ricci, V., Backert, S. (2017)
Helicobacter pylori Employs a Unique Basolateral Type IV Secretion Mechanism for CagA Delivery. Cell Host Microbe 22: 552-560. doi:10.1016/j.chom.2017.09.005.

111.) Tegtmeyer, N., Backert, S. (2017)
Helicobacter pylori infection of AZ-521 cells reveals a type IV secretion defect and VacA-independent CagA phosphorylation. Disease Models & Mechanisms 10: 1539-1540. doi:10.1242/dmm.032813.

112.) Pachathundikandi SK, Backert S. (2018)
Helicobacter pylori controls NLRP3 expression by regulating hsa-miR-223-3p and IL-10 in cultured and primary human immune cells. Innate Immunity 24: 11-23. doi:10.1177/1753425917738043.

113.) Smet, A., Yahara, K., Rossi, M., Tay, A., Backert, S., Armin, E., Fox, J.G., Flahou, B., Ducatelle, R., Haesebrouck, F., Corander, J. (2018)
Macroevolution of gastric Helicobacter species unveils interspecies admixture and time of divergence. The ISME Journal 12: 2518-2531. doi:10.1038/s41396-018-0199-5.

114.) Backert, S., Tegtmeyer, N., Oyarzabal, O.A., Osman, D., Rohde, M., Grützmann, R., Vieth M. (2018)
Unusual Manifestation of Live Staphylococcus saprophyticus, Corynebacterium urinapleomorphum, and Helicobacter pylori in the Gallbladder with Cholecystitis. International Journal of Molecular Sciences 19: E1826. doi:10.3390/ijms19071826.

115.) Moonens, K., Hamway, Y., Neddermann, M., Reschke, M., Tegtmeyer, N., Kruse, T., Kammerer, R., Mejías-Luque, R., Singer, B.B., Backert, S., Gerhard, M., Remaut, H. (2018)
Helicobacter pylori adhesin HopQ disrupts trans dimerization in human CEACAMs. The EMBO Journal 37: e98665. doi:10.15252/embj.201798665

116.) Dunne, C., Naughton, J., Duggan, G., Loughrey, C., Kilcoyne, M., Joshi, L., Carrinton, S., Earley, H., Backert, S., Robbe Masselot, C., May, F.E.B., Clyne, M. (2018)
Binding of Helicobacter pylori to Human Gastric Mucins Correlates with Binding of TFF1. Microorganisms 6: E44. doi:10.3390/microorganisms6020044

117.) Albrecht, N., Tegtmeyer, N., Sticht, H., Skórko-Glonek, J., Backert, S. (2018)
Amino-Terminal Processing of Helicobacter pylori Serine Protease HtrA: Role in Oligomerization and Activity Regulation. Frontiers in Microbiology 9: 642. DOI:10.3389/fmicb.2018.00642

118.) Zarzecka, U., Modrak-Wojcik, A., Bayassi, M., Szewczyk, M., Gieldon, A., Lesner, A., Koper, T., Bzowska, A., Sanguinetti, M., Backert, S., Lipinska, B., Skorko-Glonek, J. (2018)
Biochemical properties of the HtrA homolog from bacterium Stenotrophomonas maltophilia. International Journal of Biological Macromolecules. 109: 992-1005. DOI:10.1016/j.ijbiomac.2017.11.086

119.) Bauwens, E., Joosten, M., Taganna, J., Rossi, M., Debraekeleer, A., Tay, A., Peters, F., Backert, S., Fox, J., Ducatelle, R., Remaut, H., Haesebrouck, F., Smet, A. (2018)
In silico proteomic and phylogenetic analysis of the outer membrane protein repertoire of gastric Helicobacter species. Scientific Reports 8: 15453. doi:10.1038/s41598-018-32476-1

120.) Harrer, A., Bücker, R., Boehm, M., Zarzecka, U., Tegtmeyer, N., Sticht, H., Schulzke, J.D., Backert, S. (2019)
Campylobacter jejuni enters gut epithelial cells and impairs intestinal barrier function through cleavage of occludin by serine protease HtrA. Gut Pathogens 11: 4. doi:10.1186/s13099-019-0283-z.

121.) Tegtmeyer, N., Harrer, A., Schmitt, V., Singer, B.B., Backert, S. (2019)
Expression of CEACAM1 or CEACAM5 in AZ-521 cells restores the type IV secretion deficiency for translocation of CagA by Helicobacter pylori. Cellular Microbiology 21: e12965. doi: 10.1111/cmi.12965.

122.) Neddermann, M., Backert, S. (2019)
How many protein molecules are secreted by single Helicobacter pylori cells: quantification of serine protease HtrA. Cellular Microbiology 1: e13022. doi: 10.1111/cmi.13022.

123.) Neddermann, M., Backert, S. (2019)
Quantification of serine protease HtrA molecules secreted by the foodborne pathogen Campylobacter jejuni. Gut Pathogens 11: 14. doi: 10.1186/s13099-019-0295-8

124.) Gutiérrez-Escobar ,A.J., Bravo, M.M., Acevedo, O., Backert, S. (2019)
Molecular evolution of the VacA p55 binding domain of Helicobacter pylori in mestizos from a high gastric cancer region of Colombia. PeerJ. 7: e6634. doi: 10.7717/peerj.6634.

125.) Pachathundikandi, S.K., Tegtmeyer, N., Arnold, I.C., Lind, J., Neddermann, M., Falkeis-Veits, C., Chattopadhyay, S., Brönstrup, M., Tegge, W., Hong, M., Sticht, H., Vieth, M., Müller, A., Backert, S. (2019)
T4SS-dependent TLR5 activation by Helicobacter pylori infection. Nature Commununications 10: 5717. doi:10.1038/s41467-019-13506-6.

126.) Zarzecka, U., Harrer, A., Zawilak-Pawlik, A., Skorko-Glonek, J., Backert, S. (2019)
Chaperone activity of serine protease HtrA of Helicobacter pylori as a crucial survival factor under stress conditions. Cell Commununication and Signalling 17: 161. doi:10.1186/s12964-019-0481-9.

127.) Zarzecka, U., Modrak-Wójcik, A., Figaj, D., Apanowicz, M., Lesner, A., Bzowska, A., Lipinska, B., Zawilak-Pawlik, A., Backert, S., Skorko-Glonek, J. (2019)
Properties of the HtrA Protease From Bacterium Helicobacter pylori Whose Activity Is Indispensable for Growth Under Stress Conditions. Frontiers in Microbiology. 10: 961. doi:10.3389/fmicb.2019.00961.

128.) Zawilak-Pawlik, A., Zarzecka, U., Żyła-Uklejewicz, D., Lach, J., Strapagiel, D., Tegtmeyer, N., Böhm, M., Backert, S., Skorko-Glonek, J. (2019)
Establishment of serine protease htrA mutants in Helicobacter pylori is associated with secA mutations. Science Reports 9(1): 11794. doi:10.1038/s41598-019-48030-6.

129.) Buß, M., Tegtmeyer, N., Schnieder, J, Dong, X., Li, J., Springer, T.A., Backert, S., Niemann, H.H. (2019)
Specific high affinity interaction of Helicobacter pylori CagL with integrin αV β6 promotes type IV secretion of CagA into human cells. FEBS Journal 286(20): 3980-3997. doi:10.1111/febs.14962.

130.) Valenzuela-Valderrama, M., Cerda-Opazo, P., Backert, S., González, M.F., Carrasco-Véliz, N., Jorquera-Cordero, C., Wehinger, S., Canales, J., Bravo, D., Quest, A.F.G.. (2019)
The Helicobacter pylori Urease Virulence Factor Is Required for the Induction of Hypoxia-Induced Factor-1α in Gastric Cells. Cancers (Basel). 11(6). pii: E799. doi:10.3390/cancers11060799.

131.) Schmidt AM, Escher U, Mousavi S, Tegtmeyer N, Boehm M, Backert S, Bereswill S, Heimesaat MM. (2019)
Immunopathological properties of the Campylobacter jejuni flagellins and the adhesin CadF as assessed in a clinical murine infection model. Gut Pathogogens 11:24. doi:10.1186/s13099-019-0306-9

132.) Schmidt, A.M., Escher, U.,Mousavi, S., Boehm, M., Backert, S., Bereswill, S., Heimesaat, M.M.  (2019)
Protease Activity of Campylobacter jejuni HtrA Modulates Distinct Intestinal and Systemic Immune Responses in Infected Secondary Abiotic IL-10 Deficient Mice. Frontiers in Cellular  and Infection Microbioly 9: 79. doi: 10.3389/fcimb.2019.00079.

133.) Simson, D., Boehm, M., Backert, S. (2020)
HtrA-dependent adherence and invasion of Campylobacter jejuni in human vs. avian cells. Letters of Applied Microbiology. doi:10.1111/lam.13277. [Epub ahead of print]

 

II Review Articles

134.) Backert, S., Nielsen, B.L., Börner, T. (1997)
The mystery of the rings: structure and replication of the mitochondrial genome in higher plants. Trends in Plant Sciences 2: 477-483. https://doi.org/10.1016/S1360-1385(97)01148-5

135.) Backert, S., Churin Y., Meyer, T.F. (2002)
Helicobacter pylori type IV secretion, host cell signalling and vaccine development. Keio Journal of Medicine 51 Suppl. 2: 6-14. DOI:10.2302/kjm.51.supplement2_6

136.) Selbach, M., Backert, S. (2005)
Cortactin: an Achilles´ heel of the actin cytoskeleton targeted by pathogens. Trends in Microbiology 13: 181-189. DOI:10.1016/j.tim.2005.02.007

137.) König, W., H. Lauf, U. Arnold, I. Tammer, B. Ghebremedhin, A. Clarici, F.L. Thies, A. Drynda, A. Schmalcz, T. Kwok, R. Arnold, S. Backert, Werchau, H., König, B. (2004)
Natürliche und adaptive Immunität des Respirationstraktes – Bedeutung mikrobieller Faktoren für Infektabwehr und Sensibilisierung, Atemwegs & Lungenkrankungen, 30, Teil 1 Nr. 11: 551–568.

138.) König, W., Lauf, H., Arnold, U., Tammer, I., Ghebremedhin, B., Clarici, A., Thies, F.L., Drynda, A., Schmalcz, A., Kwok, T., Arnold, R., Backert, S., Werchau, H., König, B. (2004)
Natürliche und adaptive Immunität des Respirationstraktes – Bedeutung mikrobieller Faktoren für Infektabwehr und Sensibilisierung, Atemwegs & Lungenkrankungen 30, Teil 2 Nr. 12: 605-620.

139.) König, W., H. Lauf, U. Arnold, I. Tammer, B. Ghebremedhin, A. Clarici, F.L. Thies, A. Drynda, A. Schmalcz, T. Kwok, R. Arnold, Backert, S., Werchau, H., König, B. (2005)
Natürliche und adaptive Immunität des Respirationstraktes – Bedeutung mikrobieller Faktoren für Infektabwehr und Sensibilisierung, Atemwegs & Lungenkrankungen 31, Teil3 Nr. 4: 188-203.

140.) Backert, S., Selbach, M. (2005)
Tyrosine-phosphorylated microbial effector proteins: the enemies within. Trends in Microbiology 13: 476-484. DOI:10.1016/j.tim.2005.08.002

141.) Backert, S., König, W. (2005)
Interplay of bacterial toxins with host defence: molecular mechanisms of immunomodulatory signaling. International Journal of Medical Microbiology 295: 519-530. DOI:10.1016/j.ijmm.2005.06.011

142.) Backert, S., Meyer, T.F. (2006)
Type IV secretion systems and their effector proteins in bacterial pathogenesis. Current Opinion in Microbiology 9: 207-217. DOI:10.1016/j.mib.2006.02.008

143.) Backert, S., Fischer, W. (2007)
Transport von Proteinen und DNA: Typ IV-Sekretion bei Gram-negativen Bakterien. Naturwissenschaftliche Rundschau 60: 10-17.

144.) Backert, S., Feller, S.M., Wessler, S. (2008)
Emerging roles of Abl family tyrosine kinases in microbial pathogenesis.
Trends in Biochemical Sciences 33: 80-90. DOI:10.1016/j.tibs.2007.10.006

145.) Hänel, I., Alter, T., Backert, S. (2008)
25th Jenaer Symposium: Campylobacter Infections. Bundesgesundheitsblatt Gesundheitsforschung Gesundheitsschutz. 51: 1347-1352. doi: 10.1007/s00103-008-0705-4

146.) Wessler, S., Backert, S. (2008)
Molecular mechanisms of epithelial-barrier disruption by Helicobacter pylori. Trends in Microbiology 16: 397-405. DOI:10.1016/j.tim.2008.05.005

147.) Backert, S., Selbach, M. (2008)
Role of type IV secretion in Helicobacter pylori pathogenesis. Cellular Microbiology 10: 1573-1581. DOI:10.1111/j.1462-5822.2008.01156.x

148.) Torres, J., Backert, S. (2008)
Pathogenesis of Helicobacter pylori infection. Helicobacter 13 (Suppl. 1):13-17. DOI:10.1111/j.1523-5378.2008.00630.x

149.) Backert, S., Fronzes, R., Waksman, G. (2008)
VirB2 and VirB5 proteins: specialized adhesins in bacterial type-IV secretion systems? Trends in Microbiology 16: 409-413. DOI:10.1016/j.tim.2008.07.001

150.) Backert, S., Kenny, B., Gerhard, R., Tegtmeyer, N., Brandt, S. (2010)
PKA-mediated phosphorylation of EPEC-Tir at serine residues 434 and 463: A novel pathway in regulating Rac1 GTPase function. Gut Microbes 1: 94-99. DOI:10.4161/gmic.1.2.11437

151.) Backert, S., Tegtmeyer, N. (2010)
The Versatility of the Helicobacter pylori Vacuolating Cytotoxin VacA in Signal Transduction and Molecular Crosstalk. Toxins 2: 69-92. DOI:10.3390/toxins2010069

152.) Stradal. T.E.B., Backert, S. (2010)
Wie EHEC das Aktinzytoskelett der Wirtszelle beeinflussen. Biospektrum 16: 624-627.

153.) Backert, S., Naumann, M., (2010)
What a disorder: pro-inflammatory signaling pathways  induced by Helicobacter pylori . Trends in Microbiology 18: 479-486. DOI:10.1016/j.tim.2010.08.003

154.) Tegtmeyer, N., Backert, S., (2011)
Role of Abl and Src family kinases in actin-cytoskeletal rearrangements induced by the Helicobacter pylori CagA protein. European Journal of Cell Biology 90: 880-890. DOI:10.1016/j.ejcb.2010.11.006

155.) Backert, S., Clyne., M (2011)
Pathogenesis of Helicobacter pylori infection. Helicobacter 16: 19-25. DOI:10.1111/j.1523-5378.2011.00876.x

156.) Backert, S., Clyne, M., Tegtmeyer, N. (2011)
Molecular mechanisms of gastric epithelial cell adhesion and injection of CagA by Helicobacter pylori. Cell Communication & Signaling 9: 28-35. DOI:10.1186/1478-811X-9-28

157.) Tegtmeyer, N., Wessler, S., Backert, S. (2011)
Role of the cag-pathogenicity island encoded type IV secretion system in Helicobacter pylori pathogenesis. FEBS Journal 278: 1190-1202. DOI:10.1111/j.1742-4658.2011.08035.x

158.) Ó Cróinín, T., Backert, S. (2012)
Host epithelial cell invasion by Campylobacter jejuni: trigger or zipper mechanism? Frontiers in Cellular & Infection Microbiology 2: 25. DOI:10.3389/fcimb.2012.00025

159.) Gölz, S., Sharbati, S., Backert, S., Alter T. (2012)
Quorum sensing dependant phenotypes and their molecular mechanisms in Campylobacterales. European Journal of Microbiology & Immunology 2: 50-60. DOI:10.1556/EuJMI.2.2012.1.8

160.) Backert, S., Tegtmeyer, N. (2012)
Helicobacter pylori CagA tertiary structure reveals functional insights. CELL host & microbe 12: 3-5. DOI:10.1016/j.chom.2012.07.001

161.) Smolka, A.J., Backert, S. (2012)
How Helicobacter pylori infection controls gastric acid secretion. Journal of Gastroenterology 47: 609-618. DOI:10.1007/s00535-012-0592-1

162.) Backert, S., Hofreuter, D. (2013)
Molecular methods to investigate adhesion, transmigration, invasion and intracellular survival of the foodborne pathogen Campylobacter jejuni. Journal of Microbiological Methods 95: 8-23. DOI:10.1016/j.mimet.2013.06.031

163.) Backert, S., Boehm, M., Wessler, S., Tegtmeyer, N. (2013)
Transmigration route of Campylobacter jejuni across polarized intestinal epithelial cells: paracellular, transcellular or both? CELL Communication and Signaling 11: 72. DOI:10.1186/1478-811X-11-72

164.) Posselt, G., Backert, S., Wessler, S. (2013)
The functional interplay of Helicobacter pylori factors with gastric epithelial cells induces a multi-step process in pathogenesis. CELLl Communication and Signaling 11: 77. DOI:10.1186/1478-811X-11-77

165.) Pachathundikandi, S.K., Tegtmeyer, N., Backert, S. (2013)
Signal transduction of Helicobacter pylori during interaction with host cell protein receptors of epithelial and immune cells. Gut Microbes 4: 454-474. DOI:10.4161/gmic.27001

166.) Fernandez-Gonzalez, E., Backert, S. (2014)
DNA transfer in the gastric pathogen Helicobacter pylori. Journal of Gastroenterology 49: 594-604. DOI:10.1007/s00535-014-0938-y

167.) Pachathundikandi, S.K., Lind, J., Tegtmeyer, N., El-Omar, E.M., Backert, S. (2015)
Interplay of the gastric pathogen Helicobacter pylori with Toll-like receptors. BioMedical Research International 2015:192420. DOI:10.1155/2015/192420

168.) Backert, S., Tegtmeyer, N., Fischer, W. (2015)
Composition, structure and function of the Helicobacter pylori cag pathogenicity island encoded type IV secretion system. Future Microbiology 10:955-965. DOI:10.2217/fmb.15.32

169.) Backert, S., Neddermann, M., Maubach, G., Naumann, M. (2016)
Pathogenesis of Helicobacter pylori infection. Helicobacter 21 Suppl 1:19-25. DOI:10.1111/hel.12335

170.) Backert, S., Blaser, M.J. (2016)
The Role of CagA in the Gastric Biology of Helicobacter pylori. Cancer Research 76: 4028-4031. DOI:10.1158/0008-5472.CAN-16-1680

171.) Pachathundikandi, S.K., Müller, A., Backert, S. (2016)
Inflammasome Activation by Helicobacter pylori and Its Implications for Persistence and Immunity. Current Topics in Microbiology and Immunology 397: 117-131. DOI:10.1007/978-3-319-41171-2_6

172.) Tegtmeyer, N., Neddermann, M., Asche, C.I., Backert, S. (2017)
Subversion of host kinases: a key network in cellular signaling hijacked by Helicobacter pylori CagA. Molecular Microbiology 105: 358-372. DOI:10.1111/mmi.13707

173.) Backert, S., Tegtmeyer, N. (2017)
Type IV Secretion and Signal Transduction of Helicobacter pylori CagA through Interactions with Host Cell Receptors. Toxins (Basel) 9. DOI:10.3390/toxins9040115

174.) Backert, S., Schmidt, T.P., Harrer, A, Wessler, S. (2017)
Exploiting the Gastric Epithelial Barrier: Helicobacter pylori’s Attack on Tight and Adherens Junctions. Current Topics in Microbiology and Immunology 400: 195-226. DOI:10.1007/978-3-319-50520-6_9

175.) Wessler S, Schneider G, Backert S. (2017)
Bacterial serine protease HtrA as a promising new target for antimicrobial therapy? Journal of Cell Communication and Signaling 15: 4. DOI:10.1186/s12964-017-0162-5

176.) Naumann, M., Sokolova, O., Tegtmeyer, N., Backert, S. (2017)
Helicobacter pylori: A Paradigm Pathogen for Subverting Host Cell Signal Transmission. Trends in Microbiology 25: 316-328. DOI:10.1016/j.tim.2016.12.004

177.) Wessler, S., Backert, S. (2017)
A novel basolateral type IV secretion model for the CagA oncoprotein of Helicobacter pylori. Microbial Cell 5: 60-62. doi:10.15698/mic2018.01.611

178.) Backert, S., Haas, R., Gerhard, M., Naumann, M. (2017)
The Helicobacter pylori Type IV Secretion System Encoded by the cag Pathogenicity Island: Architecture, Function, and Signaling. Current Topics in Microbiology and Immunology 413: 187-220. DOI:10.1007/978-3-319-75241-9_8

179.) Grohmann, E., Christie, P.J., Waksman, G., Backert, S. (2018)
Type IV Secretion in Gram-negative and Gram-positive Bacteria. Molecular Microbiology 107: 455-471. doi:10.1111/mmi.13896. Erratum:  Curr Top Microbiol Immunol. 2017;413:E1. doi:10.1007/978-3-319-75241-9_14.

180.) Backert, S., Bernegger, S., Skórko-Glonek, J., Wessler, S. (2018)
Extracellular HtrA serine proteases: An emerging new strategy in bacterial pathogenesis. Cellular Microbiology 20: e12845. doi:10.1111/cmi.12845.

181.) Pachathundikandi, K., Backert, S. (2018)
Heptose 1,7-Bisphosphate Directed TIFA Oligomerization: A Novel PAMP-Recognizing Signaling Platform in the Control of Bacterial Infections. Gastroenterology. 154: 778-783. doi:10.1053/j.gastro.2018.01.009.

182.) Boehm, M., Simson, D., Escher, U., Schmidt, A.M., Bereswill, S., Tegtmeyer, N., Backert, S., Heimesaat, M.M. (2018)
Function of Serine Protease HtrA in the Lifecycle of the Foodborne Pathogen Campylobacter jejuni. European Journal of Microbiology and Immunology (Bp) 8: 70-77. doi:10.1556/1886.2018.00011.

183.) Pachathundikandi SK, Blaser N, Backert S. (2019)
Mechanisms of Inflammasome Signaling, microRNA Induction and Resolution of Inflammation by Helicobacter pylori. Current Topics in Microbiology and Immunology 421: 267-302. doi:10.1007/978-3-030-15138-6_11.

 

184.) Rudnicka, K., Backert, S, Chmiela, M. (2019)
Genetic Polymorphisms in Inflammatory and Other Regulators in Gastric Cancer: Risks and Clinical Consequences. Current Topics in Microbiology and Immunology. ;421: 53-76. doi:10.1007/978-3-030-15138-6_3.

185.) Blaser, N., Backert S, Pachathundikandi, S.K. (2019)
Immune Cell Signaling by Helicobacter pylori: Impact on Gastric Pathology. Advances in Experimental Medical Biology. 1149: 77-106. doi:10.1007/5584_2019_360.

186.) Knorr, J., Ricci, V., Hatakeyam,a M., Backert, S. (2019)
Classification of Helicobacter pylori Virulence Factors: Is CagA a Toxin or Not? Trends in Microbiology 27: 731-738. doi:10.1016/j.tim.2019.04.010

187.) Sharafutdinov, I., Backert, S., Tegtmeyer, N. (2020)
Cortactin: A Major Cellular Target of the Gastric Carcinogen Helicobacter pylori. Cancers (Basel).12(1). pii: E159. doi:10.3390/cancers12010159.

 

III Books and book chapters

188.) Backert, S. (1996)
Untersuchungen zur Struktur und Replikation des Mitochondriengenoms von Chenopodium album (L.), Shaker-Verlag, Aachen (ISBN-Nr.:3-8265-1383-5).

189.) Backert, S., Moyer, P., Böhm, C., Riecken, E.-O., Hanski, C. (1998)
Differential gene expression in cell lines derived from colon carcinoma or normal colonic mucosa, Jahrbuch der 8. Wissenschaftswoche an der FU-Berlin (ISBN-Nr.: 3-9806076-5-8): pp. 45-46.

190.) Backert, S., König, W., Arnold, R., König, B. (2006)
Induction and modulation of inflammatory networks by bacterial protein toxins. In “The Sourcebook of Bacterial Protein Toxins”, edited by J. E. Alouf, M. R. Popoff, Academic Press, New York. Section V, Chapter 54: pp. 887-918. ISBN 978-1-84593-594-8

191.) Backert, S., H. Mimuro, D.A. Israel, R.M. Peek jr. (2010)
Virulence factors in Helicobacter pylori, in: Helicobacter pylori in the 21st century. CABI-Verlag, edited by: P. Sutton and H.M. Mitchell, pp. 212-247. ISBN 978-1-84593-594-8

192.) Wessler, S., Backert, S., (2011)
The Abl Family of Tyrosine Kinases and Microbial Pathogenesis. International Reviews in Cell and Molecular Biology 286, Elsevier, edited by Kwang W. Jeon, pp. 271-300. ISBN 978-0-12385-859-7 doi: 10.1016/B978-0-12-385859-7.00006-9.

193.) Oyarzabal, O.A., Backert, S. Eds. (2012)
Microbial Food Safety, Springer New York, ISBN-Nr.: 978-1-4614-1176-5.

194.) Tegtmeyer, N., Rohde, M., Backert, S. (2012)
Clinical presentations and pathogenicity mechanisms of bacterial foodborne diseases. In “Microbial Food Safety”, Springer New York, edited by O.A. Oyarzabal & S. Backert. ISBN-Nr.: 978-1-4614-1176-5.

195.) Oyarzabal, O.A., Backert, S. (2012)
Food safety resources. In “Microbial Food Safety”, Springer New York, edited by O.A. Oyarzabal & S. Backert. ISBN-Nr.: 978-1-4614-1176-5.

196.) Backert, S., Zanotti, G., Lind, J., Asche, C.I., Tegtmeyer, N. (2016)
Roles of the cagPAI and CagA on gastroduodenal diseases. In “Helicobacter pylori research: from bench to bedside”, Springer New York, edited by S. Backert & Y. Yamaoka, ISBN-10: 4431559345.

197.) Backert, S., Y. Yamaoka (2016)
Helicobacter pylori research: from bench to bedside”, Springer Tokio, edited by S. Backert & Y. Yamaoka, ISBN-10: 4431559345.

198.) Omar A. Oyarzabal, O.A., Backert, S. (2016)
Control of Campylobacter spp. in Commercial Poultry Production. In “Campylobacter spp. and related organisms in poultry: relationship pathogen host, diagnosis and epidemiology”, Springer New York, edited by B.B. Fonseca, D.A. Rossi & H. Fernandez ISBN 978-3-319-29907-5

199.) Backert, S., Tegtmeyer, N., O’Croinin, T., Böhm, M., Heimesaat, M. (2016)
Human Campylobacteriosis. In ”Features, Detection and Prevention of Foodborne Disease: Campylobacter”, Elsevier, edited by G. Klein ISBN: 978-0-12-803623-5

200.) Backert, S. (2016)
“Inflammasome signalling and bacterial infections”, Springer Heidelberg, edited by S. Backert. ISBN: 978-3-319-41170-5
.
201.) Backert, S. (2016)
Preface in “Inflammasome signalling and bacterial infections”, Springer Heidelberg, edited by S. Backert. pp. 5-6, ISBN: 978-3-319-41170-5

202.) Oyarzabal, O.A., Backert, S. (2017)
Varying pathogenicity of Campylobacter jejuni isolates. In “Foodborne Pathogens: Virulence Factors and Host Susceptibility”, Springer New York, edited by J. Gurtler ISBN 978-3-319-56836-2

203.) Tegtmeyer, N., Backert, S. (2017)
”Molecular pathogenesis and signal transduction by Helicobacter pylori” Springer,
ISBN 978-3-319-505190

204.) Tegtmeyer, N., Backert, S. (2017)
Preface in ”Molecular pathogenesis and signal transduction by Helicobacter pylori”. pp. 9-11. Springer, ISBN 978-3-319-50520-6

205.) Backert, S., Grohmann, E. (2017)
”Type IV Secretion in Gram-positive and Gram-negative Bacteria” Springer, ISBN: 9783319752402

206.) Backert, S. (2019) Molecular mechanisms of inflammation: induction, resolution and escape by Helicobacter pylori. Springer, ISBN: 978-3030151379

207.) Kamiya, S., Backert S. (2019) Helicobacter pylori in human diseases. Springer ISBN 978-3-030-21916-1.