SEROLOGICAL ANALYSIS OF A SUBGROUP OF HUMAN T-LYMPHOTROPIC RETROVIRUSES (HTLV-III) ASSOCIATED WITH AIDS

The 2 main subgroups of the family of human T-lymphotropic retroviruses (HTLV [human T cell leukemia-lymphoma virus]) that have previously been characterized are known as HTLV-I and HTLV-II. Both are associated with certain human leukemias and lymphomas. Cell surface antigens (p61 and p65) encoded by HTLV -I are frequently recognized, at low titers, by antibodies in the serum of patients with acquired immunodeficiency syndrome (AIDS) or with signs or symptoms that precede AIDS (pre-AIDS). This suggests an involvement of HTLV in these disorders. Another subgroup of HTLV, designated HTLV-III, has now been isolated from many patients with AIDS and pre-AIDS. Virus-associated antigens in T-cell clones permanently producing HTLV-III were subjected to biochemical and immunological analyses. Antigens of HTLV-III, specifically detected by antibodies in serum from AIDS or pre-AIDS patients and revealed by the Western blot technique, were similar in size to those found in other subgroups of HTLV. They included at least 3 serologically unrelated antigenic groups, 1 of which was associated with group-specific antigens (p55 and p24) and another with envelope-related (p65) proteins; the antigens in the 3rd group were of unknown affiliation. Thus, HTLV-III is clearly distinguishable from HTLV-I and HTLV-II but is also significantly related to both viruses. HTLV-III is thus a true member of the HTLV family.