title: Selective deletion of CD8(+) cells upregulated by caspases-1 via IL-18 in mice immunized with major outer membrane protein of Shigella dysenteriae 1 following infection.
abstract: BACKGROUND
  Mucosal lymphoid changes were observed in cryopreserved rectal tissues obtained from BALB/c mice infected with Shigella dysenteriae 1, immunized with 57-kDa major antigenic outer membrane protein, and infection after immunization.
  
  
  CONCLUSIONS
  Our data suggested that caspase-3 is downregulated in CD4(+) cells of immunized BALB/c mice following infection with substantial increased expression of interleukin (IL)-2 and interferon (IFN)-gamma, while caspase-1 is upregulated in CD8(+) cells with decreased expression of IL-4 and IL-10. This indicated an involvement of Fas-mediated lytic pathway for selective deletion of CD8(+) cells out of CD3(+) T cells. IL-18 promotes inflammation and induces IFN-gamma and tumor necrosis factor (TNF)-alpha as the expression of IFN-gamma and TNF-alpha cytokines was evident in this study. It is assumed that the role of caspase-1 in inducing the CD4+ T cell activity increased with IL-18 rather than CD8+ suppressor cell activity. Bcl-2 is capable of inhibiting the Fas/Fas-L-mediated cell death for helper cells. Overall, the findings indicate that majority of the apoptotic cells were CD8(+) T cells in the groups of infection following immunization, and there might be a selective deletion of T lymphocytes mediated by caspase-1 via IL-18.
authors.affiliation: Research & Development Division, Nutratech, Inc., Winnipeg, MB, R3Y 1M5, Canada. ashim_k_bagchi333@yahoo.co.in
authors.forename: Ashim Kumar
authors.initials: AK
authors.lastname: Bagchi
authors.forename: Ajoy Kumar
authors.initials: AK
authors.lastname: Sinha
authors.forename: Rushita
authors.initials: R
authors.lastname: Adhikari
authors.forename: Pradip
authors.initials: P
authors.lastname: Maiti
authors.forename: Joydeep
authors.initials: J
authors.lastname: Mukherjee
authors.forename: Arpita
authors.initials: A
authors.lastname: Panda
authors.forename: Dhira Rani
authors.initials: DR
authors.lastname: Saha
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000276:immunology; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000378:metabolism*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism / Q000382:microbiology / Q000473:pathology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology / Q000378:metabolism* / Q000382:microbiology / Q000473:pathology; D020170:Caspase 1 / Q000378:metabolism; D053148:Caspase 3 / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D017637:Clonal Deletion; D016207:Cytokines / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D004405:Dysentery, Bacillary / Q000097:blood / Q000276:immunology*; D018928:Immunity, Mucosal; D007114:Immunization; D007070:Immunoglobulin A / Q000096:biosynthesis / Q000097:blood / Q000235:genetics; D007074:Immunoglobulin G / Q000097:blood; D008213:Lymphocyte Activation; D051379:Mice; D008807:Mice, Inbred BALB C; D012762:Shigella dysenteriae / Q000276:immunology* / Q000472:pathogenicity
chemical_list: D001425:Bacterial Outer Membrane Proteins; D016207:Cytokines; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D053148:Caspase 3; D020170:Caspase 1