title: Effective ex vivo neutralization of human immunodeficiency virus type 1 in plasma by recombinant immunoglobulin molecules.
abstract: We tested the ability of human monoclonal antibodies (immunoglobulin G1b12 [IgG1b12] and 19b) and CD4-based molecules (CD4-IgG2 and soluble CD4 [sCD4]) to neutralize human immunodeficiency virus type 1 directly from the plasma of seropositive donors in an ex vivo neutralization assay. IgG1b12 and CD4-IgG2, at concentrations from 1 to 25 micrograms/ml, were found to be effective at reducing the HIV-1 titer in most plasma samples. When viruses recovered from plasma samples were expanded to produce virus stocks, no correlation between the neutralization sensitivities to IgG1b12 and CD4-IgG2 of the in vitro passaged stocks and those of the ex vivo neutralizations performed directly on the plasma was observed. These differences could be due to changes in neutralization sensitivity that occur after one passage of the virus in vitro, or they could be related to the presence of complement or antibodies in the plasma. Furthermore, differences in expression of adhesion molecules on plasma-derived and phytohemagglutinin-activated peripheral blood mononuclear cell-derived viruses could be involved. These studies suggest that IgG1b12 and CD4-IgG2 have broad and potent neutralizing activity in both in vitro and ex vivo neutralization assays and should be considered for use as potential immunoprophylactic or therapeutic agents.
authors.affiliation: Aaron Diamond AIDS Research Center, New York, NY 10016, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Gauduin
authors.forename: G P
authors.initials: GP
authors.lastname: Allaway
authors.forename: P J
authors.initials: PJ
authors.lastname: Maddon
authors.forename: C F
authors.initials: CF
authors.lastname: Barbas
authors.forename: D R
authors.initials: DR
authors.lastname: Burton
authors.forename: R A
authors.initials: RA
authors.lastname: Koup
mesh_terms: D000911:Antibodies, Monoclonal / Q000276:immunology*; D000998:Antiviral Agents / Q000494:pharmacology; D015704:CD4 Antigens / Q000494:pharmacology; D016860:CD4 Immunoadhesins / Q000494:pharmacology; D015483:HIV Antibodies / Q000276:immunology*; D006679:HIV Seropositivity / Q000097:blood / Q000276:immunology / Q000821:virology; D015497:HIV-1 / Q000187:drug effects / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000276:immunology; D009500:Neutralization Tests; D011994:Recombinant Proteins / Q000276:immunology / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; D000998:Antiviral Agents; D015704:CD4 Antigens; D016860:CD4 Immunoadhesins; C096753:CD4-IgG(2); D015483:HIV Antibodies; D007074:Immunoglobulin G; D011994:Recombinant Proteins; C076613:recombinant soluble CD4