INHIBITION OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1 REPLICATION IN MYELOMONOCYTIC CELLS DERIVED FROM RETROVIRAL VECTOR TRANSDUCED PERIPHERAL-BLOOD PROGENITOR CELLS

Monocytes and macrophages (Mo/M Phi) contribute to the pathogenesis of human immunodeficiency virus type 1 (HIV-1) infection, A successful h ematopoietic stem/progenitor cell (HSPC)-based gene therapy strategy f or HIV-1 disease must protect Mo/M Phi, as well as T cells from HIV-l- related pathology, In this report, we demonstrate that RevM10-transduc ed HSPCs isolated from cytokine-mobilized peripheral blood give rise t o Mo/M Phi suppressing replication of M Phi-tropic HIV-1 isolates. A M oloney murine leukemia virus (MoMLV)-based retroviral vector encoding a bicistronic mRNA co-expressing RevM10 and the murine CD8 alpha' chai n (Lyt2) was used to transduce HSPCs. Following transduction, these ce lls were expanded and differentiated by shortterm culture in methylcel lulose containing various cytokines, In vitro differentiated Mo/M Phi were enriched by fluorescence activated cell sorting (FAGS) for the co -expressed transgene (Lyt2) and myelomonocytic (CD33, CD14) surface ma rkers, HIV-1 replication of two M Phi-tropic isolates (JR-FL, Bat) was inhibited in Mo/M Phi expressing RevM10 and Lyt2 relative to control cells expressing only Lyt2 but no functional RevM10 gene product, Cell proliferation and expression of lineage-specific surface markers was not altered in transduced, in vitro differentiated Mo/M Phi, cells. Th is study supports the feasibility of HSPC-based gene therapy as a futu re treatment for HIV-1 disease.