Adriana Ravina

Role for CD30 in HIV expression.

CD30 is a member of the tumor necrosis factor (TNF)-receptor superfamily, whose ligand (CD30L) has been identified on B cells, activated macrophages and a subset of activated T cells. We show here that infection in vitro with human immunodeficiency virus (HIV) of CD4+ T-cell clones generated from HIV-seronegative individuals can enhance the expression of CD30, which often preceeds and is associated with the death of clonal T cells. Furthermore, cross-linking CD30 with an agonistic CD30-specific monoclonal antibody potentiated HIV replication induced by an insolubilized anti-CD3 antibody in T-cell lines generated from HIV-infected individuals. More importantly, paraformaldehyde-fixed CD8+ T-cell clones expressing CD30L enhanced HIV replication in anti-CD3-stimulated allogeneic or autologous HIV-infected CD4+ T-cell lines and such a potentiating effect was inhibited by an anti-CD30L antibody. The anti-CD30L antibody also exerted a suppressive effect on the spontaneous HIV replication occurring in lymph node cells, freshly derived from an HIV-seropositive patient showing CD30 expression in B cells and in a proportion of CD8+ T lymphocytes. Thus, CD30 triggering may play an important role in both HIV replication and the death of HIV-infected CD4+ T cells.

Increased production of IgE protein and IgE antibodies specific for fungal antigens in patients with the acquired immunodeficiency syndrome

SummaryLevels of IgE protein and IgE antibodies specific for 8 different allergenic extracts were measured in the serum of a large series of patients infected by the human immunodeficiency virus (HIV) and in HIV-seronegative subjects belonging to the same risk groups (intravenous drug-users, homosexual men and hemophiliacs). The proportion of subjects showing elevated IgE levels was higher among HIV-infected patients with group IV disease than among HIV-infected patients with group II–III diseases or seronegative individuals. In addition, many HIV-infected patients with elevated IgE levels showed the presence in their serum of IgE antibodies specific for fungal antigens.

Screening and confirmatory tests for antibody to HTLV-III/LAV retrovirus in individuals at risk for AIDS

SummaryThe prevalence of specific antibodies to HTLV-III/LAV retrovirus was investigated during 1985 in a large group of subjects at risk for AIDS living in the Florence area. Two hundred and thirty-two of 774 (29.9%) intravenous drug users (IDU), 40 of 164 homosexuals (24.3%), 43 of 147 hemophiliacs (29.2%), 7 of 10 children born from IDU mothers and 4 of 88 heterosexual partners of IDU were found to be seropositive using different ELISA kits. The positivity in all serum samples showing low antibody titres and/or discordant results with different sandwich ELISA kits was confirmed by a competition ELISA assay and the Western blot technique. Serum samples from 4 of 210 hemodialyzed and from one of 17 polytransfused patients also showed positive reactions in the assays based on the sandwich principle, but gave negative results in both the competition ELISA assay and the Western blot technique. In addition, all these sera showed positive reactions using immunofluorescence and ELISA procedures that control for reactivity with H9 human cell line material used for culturing the HTLV-III/LAV retrovirus. These data demonstrate that exposure to HTLV-III/LAV retrovirus is widespread in groups of subjects at risk for AIDS living in the Florence area. Furthermore, the results of the present study suggest that, in addition to the Western blot technique, the competition ELISA assay as well as assays that control reactivity with H9 human cell line material may be of value for detecting false positive reactions due to antibody cross-reactive with human cellular components.

In vitro Infection with hiv of antigen-specific t cell clones derived from hiv-seronegative individuals. effects on cytokine production and helper function

SummaryThree human T cell clones (TCC) specific for purified protein derivative of Mycobacterium tuberculosis were incubated in the presence of polybrene and phytohemagglutinin with irradiated mononuclear cells from one individual exhibiting seropositivity for human immunodeficiency virus (HIV) and high levels of circulating p24 antigen. After three weeks, TCC showed HIV integration in their DNA, as shown by polymerase chain reaction analysis and Southern blot technique. All the three HIV-infected TCC maintained their ability to recognize the specific antigen, even if their proliferative ability was reduced. The ability of the HIV-infected TCC to produce IL-2, IL-4 and IFN-y in response to phorbol myristate acetate plus anti-CD3 monoclonal antibody was decreased, whereas their ability to produce TNF-α was unaffected or even enhanced. Two our. of the three HIV-infected TCC showed the ability to provide helper function for polyclonal immunoglobulin production when cocukured with autologous B cells in the absence of any stimulant. These data suggest that in vitro infection of normal human TCC may provide a useful model for the study of immunological alterations induced by HIV.