Immunological properties of the Gag protein p24 of the acquired immunodeficiency syndrome retrovirus (human T-cell leukemia virus type III).

Abstract

Antigenic cross-reactivity of human T-cell leukemia virus type III (HTLV-III) with HTLV-I and HTLV-II and other retroviruses was measured by using a stringent homologous competition radioimmunoassay for the Gag protein p24 and a less stringent electrophoretic transfer blot assay. In the competition radioimmunoassay only minimal crossreactivities were detected between HTLV-III p24 and both HTLV-I and HTLV-II. No cross-reactivity was detected with any other retrovirus. In the electrophoretic transfer blot system using rabbit antibody to HTLV-I, HTLV-II, and HTLV-III, low-level cross-reaction was detected between HTLV-I and HTLV-IH and between HTLV-II and HTLV-IIl. Unlike the cross-reactivity between HTLV-I p24 and HTLV-III p24, which was bidirectional, the one between HTLV-II and HTLV-III was only a one-way reactivity. Antiserum to HTLV-II recognized HTLV-III p24, but the antiserum to HTLV-III did not recognize HTLV-II p24. The results indicate that HTLV-III is a unique retrovirus with a limited homology with HTLV-I and HTLV-II but unrelated to most other retroviruses.The human retrovirus human T-cell leukemia virus type III (HTLV-III) was isolated from cultured T cells of several patients with acquired immunodeficiency syndrome (AIDS), or generalized lymphadenopathy, and from asymptomatic carriers of the virus (1-3). Like HTLV-I and HTLV-II, this new isolate has a preferential tropism for OKT4+ lymphocytes and contains a Mg2+-dependent reverse transcriptase (1, 2) and a major core protein of about 24,000 daltons (4). Unlike the first two subgroups, however, HTLV-Il does not transform T cells in vitro and the in vitro transmission of the virus to fresh human T-cells only results in a transient virus production (1, 2, 5, 6). The virus could be conveniently propagated in an immortalized human neoplastic cell line (HT) and several clones of this cell line (1). Seroepidemiological assays using this virus showed a nearly complete correlation between AIDS and antibodies to HTLV-III antigens (3, 4, 7). In addition, nearly 90% of patients with lymphadenopathy syndrome and a significant but lower proportion ("40%) of asymptomatic homosexual men at risk of AIDS also carry circulating antibodies to HTLV-Ill. All of a group of patients with no risk factors for AIDS who developed AIDS after receiving blood transfusions from blood donors who were themselves seropositive showed HTLV-III antibodies (unpublished results). All of these data indicate HTLV-III to be the etiological agent for AIDS. A virus with similar properties, but described variously as lymphadenopathy-associated virus (9, 10), immune deficiency-associated virus I, and immune deficiency-associated virus II (11), has been isolated from patients with lymphadenopathy and AIDS. In the present communication we describe the antigenic characteristics of the major core protein of HTLV-III. We show that HTLV-III is a unique retrovirus with some, albeit limited, cross-reactivities with HTLV-I and HTLV-II, but not detectably related to other viruses. In addition, ...

Isolation of infectious human T-cell leukemia/lymphotropic virus type III (HTLV-III) from patients with acquired immunodeficiency syndrome (AIDS) or AIDS-related complex (ARC) and from healthy carriers: a study of risk groups and tissue sources.

“…The minimum criteria used to identify new HTLV-III isolates were (i) release of particulate, Mg2+-requiring, viral reverse transcriptase into cell culture supernatant fluids (1, 2); (ii) transmission of virus to cultures of normal human peripheral blood mononuclear cells or to permissive T-cell lines with resulting characteristic cytopathic effects and release of virus (1, 2); and (iii) detection of HTLV-III proteins by indirect immunofluorescence assays using virus-specific monoclonal antibody (13) or hyperimmune sera (12).…”

“…Six individual virus isolates further characterized by detailed immunological and nucleic acid analyses also showed relatedness to each other. Details of the protein and nucleic acid comparisons of virus isolates of HTLV-Ill have been presented elsewhere (3,4,10,12,14).…”

“…HTLV-III (2,12) or monoclonal antibodies to HTLV-Ill p24 (13). Selected cell cultures were tested for the presence of HTLV-III proteins by competition radioimmunoassays using 125I-labeled HTLV-III p24 and specific antisera (12).…”

Detection of HIV-I related antigens in rheumatoid synovial tissues.

“…In general, infections with HIV-I result in the for- Reactivity with monoclonal antibodies against HIV-I p17 and p24 (IGSS technique) reported semiquantitatively as percentage of cells labeled ( -0%, + 0.1-1 %, + + 2-5%, + + + 5%, ND: not done) mation of antibodies to virion structural as well as envelope glycoprotein antigens (32,33). We, as well as other investigators (15) were not able to detect antibodies to HIV-I viral antigens in sera of RA patients by ELISA and immunoblotting.…”

Characterization of the Serological Cross-reactivity between Glycoproteins of the Human Immunodeficiency Virus and Equine Infectious Anaemia Virus

“…Several reports have indicated that the pattern of serological reactivity observed with lentiviruses is dependent on the immunoassay employed (Montagnier et al, 1984;Sarngadharan et al, 1985;Goudsmit et al, 1986). Thus, we performed a series of immunoassays (RIP, RIA and immunoblot) to ascertain the reactivity of the respective purified surface glycoproteins of HIV (gpl20) (Robey et al, 1986) and EIAV (gp90) (Parekh et al, 1980) against a panel of sera including an AIDS patient serum pool (Robey et al, 1986), a goat serum raised against purified HIV gpl20 (Robey et al, 1986), and reference sera from horses naturally infected with EIAV (Montelaro et al, 1984a, b).…”