Abstract :We examined mouse immune response to 4 kinds of recombinant vaccinia viruses carrying the
human immunodeficiency virus type 1(HIV-1) Group-specific Antigen(gag) gene, including vacgag/pol,
which produces HIV-1-like particles with processed gag proteins; vac-gag, which also
produces HIV-1-like particles but with unprocessed gag protein; and vac-gag-pol-fuse and vaces-gag/pol,
neither of which produces such virus particles but releases Reverse Transcriptase (RT)
and gag protein, respectively, from infected cells. Although infection of mice with recombinant
vaccinia viruses induced production of the anti-HIV-1 gag protein 24 (p24) antibodies in all mice,
vac-gag/pol and vac-es-pol induced higher production than the other two recombinants. Increase in
thymidine [3H] uptake by splenic lymphocytes following HIV-1p24 antigen stimulation was most
evident in mice infected with vac-gag/pol. Thus, the highest immune response, both humoral and
cellular, was elicited by vac-gag/pol, indicating that among those tested; this recombinant vaccinia
virus is the best candidate for a vaccine that induces anti-HIV-1 gag immunity.