LACK OF T-CELL DYSFUNCTION AND PROGRAMMED CELL-DEATH IN HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 INFECTED CHIMPANZEES CORRELATES WITH ABSENCE OFMONOCYTOTROPIC VARIANTS

In asymptomatic human immunodeficiency virus (HIV) infection in humans , disturbed T cell functions such as anergy and programmed cell death, thought to result from inappropriate signaling by antigen-presenting cells due to HIV infection, precede increase in virus load, decline in CD4+ T cell numbers, and subsequent disease progression. Here, in 3 l ong-term HIV-1-infected asymptomatic chimpanzees, antigen-presenting c ell function was intact and T cells had normal proliferative capacity with no evidence of HIV-1-associated programmed cell death. Polymerase chain reaction analysis demonstrated low frequencies of cells harbori ng proviral DNA. Primary virus isolation from the infected animals dem onstrated the absence of monocytotropic HIV-1 variants, in concordance with complete insusceptibility of chimpanzee monocytes for HIV-1 infe ction. Possibly, because of the incapacity of HIV-1 to infect monocyte s, systemic immune dysfunction will not occur, contributing to control led viral replication and maintenance of the asymptomatic state in HIV -infected chimpanzees.