Preferential antibody recognition of structurally distinct HIV-1 gp120 molecules.
We have developed an assay, using a biosensor matrix and surface plasmon resonance, that rapidly and reproducibly measures antibody reactivity to human immunodeficiency virus type 1 (HIV-1) gp120 in various structural conformations. In particular, antibodies displaying preferential reactivity to a CD4-binding competent ("native," rgp120) or CD4-binding incompetent ("reduced," rcmgp120) monomeric gp120 molecule were distinguished. This technique has advantages over conventional enzyme-linked immunosorbent assay (ELISA) methodology in which it is difficult to control the concentration of protein adsorbed to the ELISA wells and a significant disruption of protein structure occurs on adsorption. A population of gp120 molecules that lacked CD4 receptor binding capacity and bound antibodies specific for reduced gp120 was found in several native gp120 preparations. The relative amount of this CD4-binding incompetent population varied among the various preparations studied. This presence of CD4-binding incompetent molecules within various native recombinant gp120 preparations may have implications for HIV-1 envelope vaccine development. By measuring antibody-binding ratios, several monoclonal antibodies were identified, which, although elicited by immunization with various native gp120 preparations, bound specifically to reduced gp120. The ability to screen antibody specificity against HIV-1 envelope proteins with different conformations will assist in determining the quality of antibodies induced by various HIV-1 envelope vaccine candidates.
VanCott
T C
TC
Department of Retroviral Research, Walter Reed Army Institute of Research, Rockville, Maryland.
Bethke
F R
FR
Kalyanaraman
V
V
Burke
D S
DS
Redfield
R R
RR
Birx
D L
DL
D016915:AIDS Vaccines / Q000276:immunology*; D000911:Antibodies, Monoclonal / Q000276:immunology; D000918:Antibody Specificity; D015374:Biosensing Techniques; D015704:CD4 Antigens / Q000276:immunology; D003429:Cross Reactions; D004306:Dose-Response Relationship, Immunologic; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000737:chemistry / Q000276:immunology; D015483:HIV Antibodies / Q000096:biosynthesis* / Q000276:immunology; D015699:HIV Envelope Protein gp120 / Q000737:chemistry / Q000276:immunology*; D015497:HIV-1 / Q000276:immunology*; D006801:Humans; D007700:Kinetics; D008024:Ligands; D011487:Protein Conformation; D011994:Recombinant Proteins / Q000737:chemistry / Q000276:immunology; D014614:Vaccines, Synthetic / Q000276:immunology
D016915:AIDS Vaccines; D000911:Antibodies, Monoclonal; D015704:CD4 Antigens; D000939:Epitopes; D015483:HIV Antibodies; D015699:HIV Envelope Protein gp120; D008024:Ligands; D011994:Recombinant Proteins; D014614:Vaccines, Synthetic