Infection of chimpanzees with lymphadenopathy-associated virus [letter]

The first lymphadenopathy-associated virus/human T-cell virus type III (LAV/HTLV-III) infection of a nonhuman primate is reported. 2 male chimpanzees whose serum contained neither antibodies to membrane antigens of HTLV-I infected living cells nor antibodies to the major core protein of LAV were injected with LAV on March 5 1984. Both animals have remained healthy. However their T4/T8 ratios fell due primarily to an increase in T8 cells. One animals ratio dropped below the normal range. Allymphocyte specimens obtained after inoculation contained retroviruses detected by reverse transcriptase assay and by fluorescence microscopy from day 7 to day 162 post innoculation. Serological evidence of infection was not detectable until 3 months after inoculation when both animals had antibodies to p25. The identification of an animal model for LAV infection has implications for the study of AIDS. 1) It offers the possibility of proof that LAV/HTLV-III is the cause of AIDS. Time will show whether these 2 LAV-infected chimpanzees will acquire the tumors or opportunistic infections characteristic of AIDS though the changes in T-cell populations may be an indication. 2) It provides an opportunity to study the natural history of LAV/HTLV-III infection. 4) It will be useful in the study of passive and active immunization.