HIV-SPECIFIC CELLULAR AND HUMORAL IMMUNE-RESPONSES IN PRIMARY HIV-INFECTION

Primary human immunodeficiency virus (HIV) infection is characterized by a high-titer viremia that declines precipitously within weeks, most likely as a result of host immune responses, Peripheral blood mononuc lear cells (PBMCs) and plasma of four recently HIV-infected individual s were examined to assess the humoral and cellular immune responses po tentially involved in early suppression of viral replication, Neutrali zing antibodies against autologous viral isolates were low or undetect able in three subjects studied, Cellular cytotoxicity was assayed usin g Epstein-Barr virus (EBV)-transformed B lymphoblastoid cell lines (B- LCLs) infected with recombinant vaccinia that express HIV-1 proteins, HIV envelope-specific cytotoxicity, which was not mediated by CD8(+) c ells nor human leukocyte antigen (HLA) class I restricted, developed i n PBMCs of all four subjects early after primary infection, but was no t correlated with declines in viremia, Gag-specific cytotoxic T lympho cyte (CTL) activity was observed in freshly isolated PBMCs of two subj ects, and HIV-specific CTL cell lines were cultured from PBMCs of thre e subjects shortly after HIV infection, Antibody-dependent cellular cy totoxicity (ADCC) developed early in all four subjects, and was tempor ally correlated with declines in viremia in two subjects in whom viral load was well characterized, These data suggest that both CTL respons es and ADCC may be critical to control of viral replication in acute H IV infection.