Epitope mapping of the HIV-1 gag region by analysis of gag gene deletion fragments expressed in Escherichia coli defines eight antigenic determinants.
Immune response to HIV infection is generally characterized by appearance of antibodies to the gag protein p24 early in infection, and by apparent loss of p24 antibodies accompanied by increases in p24 antigen levels with disease progression. Precise definition of the immunodominant epitopes present in gag gene proteins has potential clinical significance. Seventeen anti-gag monoclonal antibodies (MAb) were used in enzyme-linked immunosorbent assays (ELISA) with antigens expressed by nine recombinant clones to define epitopes on HIV gag proteins which elicit an immune response. All of the MAbs tested, except two anti-p17, reacted with a clone which expresses the carboxyl terminal 13 amino acids of p17 and all of p24 and p15. All anti-p24 MAbs reacted with clones containing all of p24. MAbs reacted differentially with clones containing deleted regions depending on the antigenic portion expressed. Of thirteen potential identifiably different genomic regions which could be predicted from the genomic structure of the clones, eight different antigen epitopes were defined: two on p17, five on p24, and one on p15 (in the region corresponding to the carboxyl terminal protein p6). Six regions did not appear to react with any of the monoclonal antibodies available. Identification of the epitopes present in the cloned antigens should allow their use to evaluate sera from HIV-infected donors at different clinical stages of progression to AIDS.
Division of Virology, Food and Drug Administration, Bethesda, MD 20892.
C J
CJ
Marcus-Sekura
A M
AM
Woerner
P F
PF
Zhang
M
M
Klutch
D000818:Animals; D000911:Antibodies, Monoclonal; D001483:Base Sequence; D015153:Blotting, Western; D002872:Chromosome Deletion; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000032:analysis*; D004926:Escherichia coli / Q000235:genetics*; D015683:Gene Products, gag / Q000032:analysis / Q000276:immunology*; D015488:HIV Antigens / Q000276:immunology*; D016655:HIV Core Protein p24; D051379:Mice; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000276:immunology; D014758:Viral Core Proteins / Q000032:analysis / Q000276:immunology*
D000911:Antibodies, Monoclonal; D000939:Epitopes; D015683:Gene Products, gag; D015488:HIV Antigens; D016655:HIV Core Protein p24; D011994:Recombinant Proteins; D014758:Viral Core Proteins