Cd8(+) T cell mediated noncytolytic inhibition of human immunodeficiency virus type I

The development of cellular immune responses in primary human immunodeficie ncy virus type-1 (HIV-1) infection is accompanied by a dramatic decrease in plasma viremia and resolution of the acute clinical syndrome. The full nat ure of the immunological response and its consequences on HIV pathogenesis is still largely a mystery, but significant progress has been achieved in t he characterization of some of the players involved. Several studies indica te that noncytolytic HIV suppression by CD8(+) T lymphocytes may be inverse ly associated with viral load Table 1. Characteristics of CD8(+) Antiviral Activity Non-cytolytic inhibition of virus replication Not HLA restricted, but some enhancement is seen when matched Dose dependent Effective against acutely or endogenously infected CD4(+) T-cells Declines with progression to AIDS Soluble and Contact mediated Effective against CCR5 and CXCR4 utilizing viruses Present in some exposed uninfected individuals suggesting that this antiviral activity is important in host control of HIV replication. This review focuses on this antiviral activity by CD8(+) T ly mphocytes, which is distinct from that activity elicited by some cytolytic CD8(+) T lymphocytes (CTLs).