Acute Effects of Pathogenic Simian-Human Immunodeficiency Virus Challenge on Vaccine-Induced Cellular and Humoral Immune Responses to Gag in Rhesus Macaques †

Krista K. Steger, Paul M. Waterman, C. David Pauza
1999 Journal of Virology  
Simian-human immunodeficiency virus (SHIV) infection in macaques provides a convenient model for testing vaccine efficacy and for understanding viral pathogenesis in AIDS. We immunized macaques with recombinant, Salmonella typhimurium (expressing Gag) or soluble Gag in adjuvant to generate T-cell-dependent lymphoproliferative or serum antibody responses. Immunized animals were challenged by intrarectal inoculation with SHIV89.6PD. Virus infection was accompanied by rapid losses of
more » ... ative responses to Gag or phytohemagglutinin. By 8 weeks, mitogen responses recovered to near normal levels but antigen-specific immunity remained at low or undetectable levels. Serum antibody levels were elevated initially by virus exposure but soon dropped well below levels achieved by immunization. Our studies show a rapid depletion of preexisting Gag-specific CD4+ T cells that prevent or limit subsequent antiviral cellular and humoral immune responses during acute SHIV infection.
doi:10.1128/jvi.73.3.1853-1859.1999 fatcat:elrkld2z5rdxbm2y6hnwxxd32q