The synthetic peptide from HIV increases functional activity of granulocytes in healthy subjects.

The influence of HIV lysate and eight synthetic peptides which are fragments of HIV proteins on the functional activity of polymorphonuclear neutrophils (PMN) was tested in 12 healthy subjects. PMN activity in nitroblue tetrazolium reduction (NBT test) and PMN chemiluminescence (CL) was studied. Only one peptide was found to result in a significant increase in NBT test on the whole blood. This was the oligopeptide (G-97) from the CD4-binding site of HIV-1 gp120. The increase of CL response of PMN in the presence of G-97 was revealed after only 15 min preincubation. The same effect in the presence of sera from healthy or infected patients at the persistent generalized lymphadenopathy stage was achieved by increasing the time of preincubation to 30 min. G-97 did not influence the proliferative activity of lymphocytes.

Production of a novel antigen by conjugation of HIV-1 to Brucella abortus: studies of immunogenicity, isotype analysis, T-cell dependency, and syncytia inhibition.

In the present study inactivated human immunodeficiency virus type 1 (HIV-1) was conjugated to Brucella abortus and tested for immunogenicity in normal and anti-L3T4-treated BALB/c mice. HIV-BA was more immunogenic than uncoupled HIV in normal mice, since 6-fold less virus in HIV-BA preparations elicited higher titer responses than HIV-1 alone. Furthermore, the HIV-BA antibody response reached higher levels before the HIV-1 response. Immunoblot analysis showed that most of the HIV-1 antigens were recognized by antibodies induced by either HIV-1 or HIV-BA. Isotype analysis revealed that HIV-1 induced similar levels of IgG1 and IgG2a antibodies, whereas the IgG2a responses to HIV-BA were more pronounced than the IgG1 response. These different IgG subclass patterns suggest that conjugation of HIV-1 to BA changed the immunogenic nature of HIV-1. The requirement for helper T cells was examined by immunizing mice that were depleted of CD4+ T cells by in vivo anti-L3T4 treatment. Under these conditions the IgG responses to HIV-1 were completely eliminated. Although HIV-BA antibody responses were markedly reduced in anti-L3T4-treated mice, anti-HIV-1 antibodies, mainly of the IgG2a isotype, were produced. The antibodies generated by HIV-1 and HIV-BA immunization were also tested for their ability to inhibit syncytia formed by infecting CD4 + CEM cells with gp160 vaccinia. Sera from normal mice, immunized with either HIV-1 or HIV-BA were capable of inhibiting syncytia. In contrast, following anti-L3T4 treatment, only mice immunized with HIV-BA, but not HIV-1, produced antibodies capable of inhibiting syncytia.

Characterization of monoclonal antibodies against the p17 core protein of the human immunodeficiency virus 1.

Five mouse hybridomas which produce monoclonal antibodies against the p17 core protein of HIV-1 have been isolated. Cross-competition assays and mapping with synthetic peptides demonstrate that two closely related epitopes are identified by these antibodies. Directed against two neighbouring peptides at the carboxy-terminal end of the molecule, they can be used for the selective detection of p17 polypeptide in a viral extract or in an infected cell lysate by a solid-phase sandwich enzyme immunoassay.

Comparative analysis of gp41 antigens by enzyme-linked immunosorbent assays for detecting antibodies to human immunodeficiency virus type 1.

We have compared the antigenic qualities of human immunodeficiency virus type 1 (HIV-1) gp41 glycoprotein with a synthetic oligopeptide (peptide R21S) and a bacterially synthesized protein (protein 566), which are homologous with the N-terminal region of gp41, in enzyme-linked immunosorbent assays (ELISA) for detecting antibodies to HIV-1 in sera of patients with the acquired immunodeficiency syndrome (AIDS) or the aids-related complex (ARC). Although the use of all three types of antigens readily allowed the detection of antibodies in human sera, ELISA employing purified gp41 glycoprotein and the protein 566 were more specific and sensitive than the peptide R21S ELISA.