Enzyme immunoassay (ELISA) for the evaluation of antibodies directed to the CD4 receptor-binding site of the HIV gp120 molecule.
The interaction between the HIV envelope glycoprotein gp120 and the CD4 molecule is probably the most important primary event determining HIV infection. Reactivity with the native viral envelope has been difficult to measure due to the lack of gp120 ligand purified directly from primary virus cultures. We have developed an ELISA, utilizing Galanthus nivalis agglutinin (GNA) which selectively binds native HIV envelope gp120 in culture medium. The GNA-based ELISA eliminates the need for isotope-labelled reagents, live cells and recombinant non-natively glycosylated envelope proteins and offers an easy way of using gp120 directly from crude HIV culture medium. The reactivities of sera from several categories of HIV infected individuals were assayed for inhibition of the HIV-1 gp120-CD4 binding. 19/32 (59.3%) sera from asymptomatic individuals and 7/10 (70%) sera from ARC/AIDS patients blocked the CD4-gp120 binding. 20 serum samples from uninfected individuals showed a gp120-CD4 interaction blocking capacity of 0-15%. Two monoclonal antibodies, T4.2 directed to CD4 and 1171 directed to the CD4 binding site of gp120 were used as positive controls. Both Mabs inhibited CD4-gp120 binding by 66-90%.
Hinkula
J
J
Swedish Institute for Infectious Disease Control, Department of Virology, Stockholm.
Gidlund
M
M
Persson
C
C
Osterhaus
A
A
Wahren
B
B
D000293:Adolescent; D000328:Adult; D001667:Binding, Competitive / Q000276:immunology; D015704:CD4 Antigens / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D000939:Epitopes / Q000276:immunology; D027801:Galanthus; D015686:Gene Products, env / Q000276:immunology; D015483:HIV Antibodies / Q000276:immunology*; D015699:HIV Envelope Protein gp120 / Q000276:immunology*; D019302:HIV Envelope Protein gp160; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D008875:Middle Aged; D009500:Neutralization Tests; D011498:Protein Precursors / Q000276:immunology
D015704:CD4 Antigens; D000939:Epitopes; D015686:Gene Products, env; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D019302:HIV Envelope Protein gp160; D011498:Protein Precursors