Low levels of SIV-specific CD8+ T cells in germinal centers characterizes acute SIV infection.

CD8+ T cells play an important role in controlling of HIV and SIV infections. However, these cells are largely excluded from B cell follicles where HIV and SIV producing cells concentrate during chronic infection. It is not known, however, if antigen-specific CD8+ T cells are excluded gradually as pathogenesis progresses from early to chronic phase, or this phenomenon occurs from the beginning infection.

Simian Immunodeficiency Virus-Producing Cells in Follicles Are Partially Suppressed by CD8+ Cells In Vivo.

Unlabelled: Human immunodeficiency virus (HIV)- and simian immunodeficiency virus (SIV)-specific CD8 T cells are typically largely excluded from lymphoid B cell follicles, where HIV- and SIV-producing cells are most highly concentrated, indicating that B cell follicles are somewhat of an immunoprivileged site. To gain insights into virus-specific follicular CD8 T cells, we determined the location and phenotype of follicular SIV-specific CD8 T cells in situ, the local relationship of these cells to Foxp3 cells, and the effects of CD8 depletion on levels of follicular SIV-producing cells in chronically SIV-infected rhesus macaques. We found that follicular SIV-specific CD8 T cells were able to migrate throughout follicular areas, including germinal centers.