Presentation of connected peptides of distinct length and conformation, homologous to self-peptides with high flexibility in their bound state. In conclusion, the higher accuracy and sensitivity of existing MS technologies brought about a significant improvement in the detection of naturally processed HLA-B27 ligands from C. trachomatis, allowing us to detect 3 novel peptides from distinct proteins, including the second recognized HLA-B27-restricted epitope recognized by T-cells from ReA individuals. Both the homology of all of the κ Opioid Receptor/KOR Inhibitor Biological Activity reported peptides with human sequences carrying the binding motif of HLA-B27 plus the finding of a peptide from DNAP with considerable sequence and conformational similarity to a human-derived HLA-B27 ligand suggest that molecular mimicry among bacterial and self-derived HLA-B27 ligands may perhaps play a part in ReA. This mechanism could supply an autoimmune component that would exacerbate the proinflammatory role of HLA-B27, influencing disease severity and evolution toward chronicity.Acknowledgments–We thank the employees with the Proteomics SMYD3 Inhibitor Synonyms facilities at the Centro de Biolog Molecular Severo Ochoa and Centro Nacional de Biotecnolog , Madrid, for help in MS.14. Jendro, M. C., Fingerle, F., Deutsch, T., Liese, A., Kohler, L., Kuipers, J. G., Raum, E., Martin, M., and Zeidler, H. (2004) Chlamydia trachomatisinfected macrophages induce apoptosis of activated T cells by secretion of tumor necrosis factor- in vitro. Med. Microbiol. Immunol. 193, 452 15. Fields, K. A., and Hackstadt, T. (2002) The chlamydial inclusion. Escape from the endocytic pathway. Annu. Rev. Cell Dev. Biol. 18, 22145 16. Beatty, W. L., Belanger, T. A., Desai, A. A., Morrison, R. P., and Byrne, G. I. (1994) Tryptophan depletion as a mechanism of interferon-mediated chlamydial persistence. Infect. Immun. 62, 3705711 17. Beatty, W. L., Belanger, T. A., Desai, A. A., Morrison, R. P., and Byrne, G. I. (1994) Role of tryptophan in interferon-mediated chlamydial persistence. Ann. N.Y. Acad. Sci. 730, 304 06 18. Zhong, G., Fan, T., and Liu, L. (1999) Chlamydia inhibits interferon -inducible significant histocompatibility complex class II expression by degradation of upstream stimulatory issue 1. J. Exp. Med. 189, 1931938 19. Zhong, G., Liu, L., Fan, T., Fan, P., and Ji, H. (2000) Degradation of transcription issue RFX5 during the inhibition of each constitutive and interferon -inducible important histocompatibility complicated class I expression in chlamydia-infected cells. J. Exp. Med. 191, 1525534 20. Zhong, G., Fan, P., Ji, H., Dong, F., and Huang, Y. (2001) Identification of a chlamydial protease-like activity factor responsible for the degradation of host transcription elements. J. Exp. Med. 193, 93542 21. Zhong, G. (2011) Chlamydia trachomatis secretion of proteases for manipulating host signaling pathways. Front. Microbiol. 2, 14 22. Loomis, W. P., and Starnbach, M. N. (2002) T cell responses to Chlamydia trachomatis. Curr. Opin. Microbiol. five, 871 23. Marcilla, M., and Lopez de Castro, J. A. (2008) Peptides. The cornerstone of HLA-B27 biology and pathogenetic part in spondyloarthritis. Tissue Antigens 71, 49506 24. Benjamin, R., and Parham, P. (1990) Guilt by association. HLA-B27 and ankylosing spondylitis. Immunol. Currently 11, 13742 25. Albert, L. J., and Inman, R. D. (1999) Molecular mimicry and autoimmunity. N. Engl. J. Med. 341, 2068 074 26. Could, E., Dorris, M. L., Satumtira, N., Iqbal, I., Rehman, M. I., Lightfoot, E., and Taurog, J. D. (2003) CD8 T cells are not important to.