A recombinant clone of HIV-1 preferentially transmitted in normal peripheral blood mononuclear cells

To study biologic properties associated with specific regions of HIV-1, a chimera, pHX-JY1, was constructed by exchanging the vif-env region of a Zairian molecular clone (JY1) with that of pHXB2gpt, a full-length biologically active proviral clone of North American origin. Virus was produced by transfection of permissive cells with parental and recombinant clones, and the biologic and molecular properties of these viruses were compared. Virus derived from pHXB2gpt infected phytohemagglutinin (PHA)-activated normal peripheral blood mononuclear cells (PBMC) and CD4+ leukemic T cell lines equally well. In contrast, virus derived from pHX-JY1 was transmitted slowly to both PBMC and cell lines, and the infectivity of pHX-JY1 virus was two orders of magnitude greater for PBMC than for T cell lines. All essential viral genes in the exchanged JY1 vif-env region were intact and functioned comparably to those of the parent clone in transfected COS-1 cells. The findings suggest differences in these regions of the HIV-1 genome may play an important role in differential cell tropism.