Rhabdovirus-based vectors with human immunodeficiency virus type 1 (HIV-1)envelopes display HIV-1-like tropism and target human dendritic cells

We describe replication-competent, vaccine strain-based rabies viruses (RVs ) that lack their own single glycoprotein and express, instead, a chimeric RV-human immunodeficiency virus type I (HIV-1) envelope protein composed of the ectodomain and transmembrane domains of HIV-1 gp160 and the cytoplasmi c domain of RV G. The envelope proteins from both X4 (NL4-3)- and R5X4 (89. 6)-tropic HIV-1 strains were utilized. These recombinant viruses very close ly mimicked an HIV-1-like tropism, as indicated by blocking experiments. In fection was inhibited by SDF-1 on cells expressing CD4 and CXCR4 for both v iruses, whereas RANTES abolished infection of cells expressing CCR5 in addi tion to CD4 in studies of the RV expressing HIV-1(89.6) Env. In addition, p reincubation with soluble CD4 or monoclonal antibodies directed against HIV -1 gp160 blocked the infectivity of both G-deficient viruses but did not af fect the G-containing RVs. Our results also indicated that the G-deficient viruses expressing HIV-1 envelope protein, in contrast to wild-type RV but similar to HIV-1, enter cells by a pH-independent pathway. As observed for HIV-1, the surrogate viruses were able to target human peripheral blood mon onuclear cells, macrophages, and immature and mature human dendritic cells (DC). Moreover, G-containing RV-based vectors also infected mature human DC , indicating that infection of these cells is also supported by RV G. The a bility of RV-based vectors to infect professional antigen-presenting cells efficiently further emphasizes the potential use of recombinant RVs as vacc ines.