High Frequency of Virus-Specific CD8 + T Cells in the Central Nervous System of Macaques Chronically Infected with Simian Immunodeficiency Virus SIVmac251

Abstract

ABSTRACT Infection with human immunodeficiency virus or simian immunodeficiency virus (SIV) induces virus-specific CD8 + T cells that traffic to lymphoid and nonlymphoid tissues. In this study, we used Gag-specific tetramer staining to investigate the frequency of CD8 + T cells in peripheral blood and the central nervous system of Mamu-A*01-positive SIV-infected rhesus macaques. Most of these infected macaques were vaccinated prior to SIVmac251 exposure. The frequency of Gag 181-189 CM9 tetramer-positive cells was consistently higher in the cerebrospinal fluid and the brain than in the blood of all animals studied and did not correlate with either plasma viremia or CD4 + -T-cell level. Little or no infection in the brain was documented for most animals by nucleic acid sequence-based amplification or in situ hybridization. These data suggest that this Gag-specific response may contribute to the containment of viral replication in this locale.