IMMUNE-COMPLEX TRANSFER ENZYME-IMMUNOASSAY THAT IS MORE SENSITIVE ANDSPECIFIC THAN WESTERN BLOTTING - FOR DETECTION OF ANTIBODY IMMUNOGLOBULIN-G TO HUMAN IMMNUNODEFICIENCY VIRUS TYPE-1 IN SERUM WITH RECOMBINANT POL AND GAG PROTEINS AS ANTIGENS

Antibody immunoglobulin G (IgG) to human immunodeficiency virus type 1 (HIV-1) in serum was detected by ultrasensitive enzyme immunoassays ( immune complex transfer enzyme immunoassays) with recombinant reverse transcriptase (rRT), p17 (rp17) and p24 (rp24) of HIV-1 as antigens an d P-D-galactosidase from Escherichia coli as the label, The immune com plex, comprising 2,4-dinitrophenyl-bovine serum albumin-recombinant pr otein conjugate, antibody IgG to HIV-1, and recombinant protein-beta-D -galactosidase conjugate, was trapped on polystyrene beads coated with affinity-purified (anti-2,4-dinitrophenyl group) IgG, eluted with eps ilon N-2,4-dinitrophenyl-L-lysine, and transferred to polystyrene bead s coated with affinity-purified (anti-human IgG gamma-chain) IgG, Boun d beta-D-galactosidase activity was assayed by fluorometry, The assays were highly reproducible with no serious serum interference, and they were much more sensitive than Western immunoblotting for the correspo nding antigens. Signals with rRT, rp17, and rp24 for asymptomatic carr iers were at least 56,000-, 680-, and 22-fold higher, respectively, th an those for seronegative individuals, and neither indeterminate nor f alse-positive results were observed, whereas some serum samples were f alse negative or false positive by Western blotting for p17 and/or p24 antigen, In some eases, seroconversion was detected earlier than by c onventional methods, Therefore, these assays are suggested to be more useful than conventional methods not only for the confirmation of anti body IgGs to RT, p17, and p24 of HIV-1 in serum but also for the detec tion of seroconversion.