Expression and immunogenicity of human immunodeficiency virus type 1 Gag expressed by a replication-competent rhabdovirus-based vaccine vector.
A replication-competent rhabdovirus-based vector expressing human immunodeficiency virus type 1 (HIV-1) Gag protein was characterized on human cell lines and analyzed for the induction of a cellular immune response in mice. We previously described a rabies virus (RV) vaccine strain-based vector expressing HIV-1 gp160. The recombinant RV was able to induce strong humoral and cellular immune responses against the HIV-1 envelope protein in mice (M. J. Schnell et al., Proc. Natl. Acad. Sci. USA 97:3544-3549, 2000; J. P. McGettigan et al., J. Virol. 75:4430-4434, 2001). Recent research suggests that the HIV-1 Gag protein is another important target for cell-mediated host immune defense. Here we show that HIV-1 Gag can efficiently be expressed by RV on both human and nonhuman cell lines. Infection of HeLa cells with recombinant RV expressing HIV-1 Gag resulted in efficient expression of HIV-1 precursor protein p55 as indicated by both immunostaining and Western blotting. Moreover, HIV-1 p24 antigen capture enzyme-linked immunosorbent assay and electron microscopy showed efficient release of HIV-1 virus-like particles in addition to bullet-shaped RV particles in the supernatants of the infected cells. To initially screen the immunogenicity of this new vaccine vector, BALB/c mice received a single vaccination with the recombinant RV expressing HIV-1 Gag. Immunized mice developed a vigorous CD8(+) cytotoxic T-lymphocyte response against HIV-1 Gag. In addition, 26.8% of CD8(+) T cells from mice immunized with RV expressing HIV-1 Gag produced gamma interferon after challenge with a recombinant vaccinia virus expressing HIV-1 Gag. These results further confirm and extend the potency of RV-based vectors as a potential HIV-1 vaccine.
McGettigan
J P
JP
Dorrance H. Hamilton Laboratories, Center for Human Virology, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, USA.
Sarma
S
S
Orenstein
J M
JM
Pomerantz
R J
RJ
Schnell
M J
MJ
D016915:AIDS Vaccines; D000818:Animals; D005434:Flow Cytometry; D015870:Gene Expression; D015683:Gene Products, gag / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D005822:Genetic Vectors; D016655:HIV Core Protein p24 / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D015497:HIV-1 / Q000235:genetics* / Q000276:immunology / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D007114:Immunization; D007371:Interferon-gamma / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D011498:Protein Precursors / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D011820:Rabies virus; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014614:Vaccines, Synthetic; D014771:Virion; D014779:Virus Replication
D016915:AIDS Vaccines; D015683:Gene Products, gag; D016655:HIV Core Protein p24; D011498:Protein Precursors; D014614:Vaccines, Synthetic; C059767:p55 gag precursor protein, Human immunodeficiency virus 1; D007371:Interferon-gamma