Study data from University Autonoma of Madrid update knowledge of salmonellosis immunology
2007 OCT 2 -- Current study results from the report, "Infection with Salmonella typhimurium has no effect on the composition and cleavage specificity of the 20S proteasome in human lymphoid cells," have been published. "Human leucocyte antigen (HLA)-B27 is strongly associated with spondyloarthropathies, including reactive arthritis. Several Gram-negative bacteria, such as Salmonella typhimurium, can trigger this disease," scientists in Madrid, Spain report. "It has been suggested that peptides derived from bacterial proteins and presented by HLA-B27 to cytotoxic T lymphocytes might show molecular mimicry with autologous peptides, leading to T-cell cross-reaction and autoimmunity. Antigen presentation in Salmonella-infected cells could be modulated by changes in the composition of the proteasome, which is the major proteolytic system that generates major histocompatibility complex class I ligands. In this study we analysed whether the composition or activity of the 20S proteasome was altered upon infection of lymphoid cells by S. typhimurium. Two-dimensional gel electrophoresis failed to show any differences between the composition of 20S proteasomes from cells infected with S. typhimurium for 24 hr, relative to non-infected cells. In addition, digestions of oxidized insulin B-chain with purified 20S proteasomes from non-infected and infected cells generated the same products, indicating that the proteasomal cleavage specificity was not altered upon infection," wrote M. Marcilla and colleagues, University Autonoma of Madrid. The researchers concluded: "These data indicate that infection of lymphoid cells by S. typhimurium fails to induce formation of immunoproteasomes or otherwise alter the proteolytic specificity of the 20S proteasome." Marcilla and colleagues published their study in Immunology (Infection with Salmonella typhimurium has no effect on the composition and cleavage specificity of the 20S proteasome in human lymphoid cells. Immunology, 2007;122(1):131-9). For more information, contact M. Marcilla, Universidad Autonoma de Madrid, Centro de Biologia Molecular Severo Ochoa (CSIC-UAM), Facultad de Ciencias, Madrid, Spain. Publisher contact information for the journal Immunology is: Blackwell Publishing Ltd., 9600 Garsington Rd., Oxford OX4 2DG, Oxon, England. Keywords: Spain, Madrid, Salmonellosis Immunology, Immunology, Salmonella. This article was prepared by Life Science Weekly editors from staff and other reports. Copyright 2007, Life Science Weekly via NewsRx.com.
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