Mono Mac 1: a new in vitro model system to study HIV-1 infection in human cells of the mononuclear phagocyte series

Throughout the years, most researchers have used continuous cell lines as i n vitro models to evaluate the immunopathogenesis of human immunodeficiency virus type-1 (HIV-1) infection. Unfortunately, the most commonly used mono cytoid malignant cells have not been shown to adequately mimic primary huma n monocyte-derived macrophages, at least with respect to HIV-1 infection, T he Mono Mac 1 cell Line has been defined as a model:system for studying bio chemical, immunological, and, genetic functions of human cells of the monoc yte/macrophage lineage, In this study, we have investigated whether Mono Ma c I represents an in vitro culture system for HIV-1 infection, Flow cytomet ric analyses revealed that Mono Mac 1 are positive for the HIV-1 primary re ceptor (CD4), as well as for the coreceptors (CXCR4, CCR5, and CCR3), Infec tivity experiments conducted with recombinant luciferase-encoding and fully infectious viruses demonstrated that Mono Mac 1 can support a highly produ ctive infection with both macrophage- and dual-tropic isolates of HIV-1, Fu rthermore, differentiation of such cells led to a marked increase in virus production, Data from semiquantitative polymerase chain reaction analysis a nd mobility shift assays indicated that-enhanced virus production in differ entiated Mono Mac 1 cells was most likely related to an increase in nuclear translocation of NF-kappaB. Mono Mac I can thus be considered as a human m onocytoid cell hue representing a proper in vitro system for studying the c omplex interactions between HIV-1 and cells of the monocyte/macrophage line age.