title: Dose-dependent lymphocyte apoptosis following respiratory infection with Vaccinia virus.
abstract: Recently there has been renewed interest in poxvirus pathogenesis, especially with regard to infection via the respiratory route. Members of this family are known to produce a number of proteins that have the potential to negatively regulate the immune response. Vaccinia virus (VACV) has been used for a number of years as a model for the study of poxvirus infection. We have previously reported a dose-dependent decrease in virus-specific CD8(+) T cells following respiratory infection with VACV. In this study we have evaluated whether more generalized immunosuppressive effects are also observed following infection with a high dose of VACV. We have found that mice infected intranasally with a high, but non-lethal, dose of VACV exhibited significant weight loss as well as decreased thymocyte number. Although these mice mounted an immune response, there was a significant increase observed in bystander T and B cell apoptosis. While increased death was apparent in both naïve and activated/memory T cells populations, naïve T cells appeared more sensitive to this effect. These findings are important for our understanding of poxvirus regulation of the immune response and extends our previous understanding of VACV-mediated immunosuppression to include generalized apoptosis in the naïve and activated/memory repertoires.
authors.affiliation: Department of Microbiology & Immunology, Wake Forest University School of Medicine, Medical Center Boulevard, Winston-Salem, NC 27157, United States.
authors.forename: Nicole L
authors.initials: NL
authors.lastname: Yates
authors.forename: Rama D
authors.initials: RD
authors.lastname: Yammani
authors.forename: Martha A
authors.initials: MA
authors.lastname: Alexander-Miller
mesh_terms: D000818:Animals; D017209:Apoptosis; D016207:Cytokines / Q000097:blood; D005260:Female; D006801:Humans; D008214:Lymphocytes / Q000276:immunology* / Q000821:virology; D051379:Mice; D008810:Mice, Inbred C57BL; D012141:Respiratory Tract Infections / Q000276:immunology* / Q000503:physiopathology / Q000821:virology; D013154:Spleen / Q000276:immunology / Q000821:virology; D014615:Vaccinia / Q000276:immunology* / Q000503:physiopathology / Q000821:virology; D014616:Vaccinia virus / Q000276:immunology*; D015431:Weight Loss
chemical_list: D016207:Cytokines