COSTIMULATION OF NAIVE CD8(-IMMUNODEFICIENCY-VIRUS TYPE-1 INFECTION()LYMPHOCYTES INDUCES CD4 EXPRESSION AND ALLOWS HUMAN)

Human immunodeficiency virus type 1 (HIV-1) infection requires cell su rface expression of CD 1. Costimulation of CD8(+)/CD4(-) T lymphocytes by anti-CD3 and anti-CD28 antibodies or by allogeneic dendritic cells induced expression of CD4 and rendered these CD8 cells susceptible to HIV-1 infection. Naive CD45RA(+) cells responded with greater express ion of CD4 than did CD45RO(+) cells. CD8(+) lymphocytes derived from f etal or newborn sources exhibited a greater tendency to express CD4, c onsistent with their naive states. This mechanism of infection suggest s HIV-induced perturbation of the CD8 arm of the immune response and c ould explain the generally rapid disease progression seen in HIV-infec ted children.