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

作者：Shengbin Li, Joy M. Folkvord, Katalin J. Kovács, Reece Wagstaff, Gwantwa Mwakalundwa, Aaron Rendahl, Eva G. Rakasz, Elizabeth Connick, Pamela J. Skinner · 发表于：PLoS Pathogens · 年份：2019 · DOI：10.1371/journal.ppat.1007311 · 被引用次数：36 · 研究领域：Immune Cell Function and Interaction、T-cell and B-cell Immunology、HIV Research and Treatment

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. In this study we determined that SIV-specific CD8+ T cells were largely excluded from follicles during early infection, we also found that within follicles, they were entirely absent in 60% of the germinal centers (GCs) examined. Furthermore, levels of SIV-specific CD8+ T cells in follicular but not extrafollicular areas significantly correlated inversely with levels of viral RNA+ cells. In addition, subsets of follicular SIV-specific CD8+ T cells were activated and proliferating and expressed the cytolytic protein perforin. These studies suggest that a paucity of SIV-specific CD8+ T cells in follicles and complete absence within GCs during early infection may set the stage for the establishment of persistent chronic infection.