DIFFERENTIAL-EFFECTS OF INTERLEUKIN-13 ON CYTOMEGALOVIRUS AND HUMAN-IMMUNODEFICIENCY-VIRUS INFECTION IN HUMAN ALVEOLAR MACROPHAGES

Alveolar macrophages, which form a principal line of defense against a variety of pulmonary pathogens, may themselves be infected by viruses like human immunodeficiency virus-1 (HIV-1), which impair their defen sive functions. Interleukin-13 (IL-13), a multifunctional cytokine, ha s been considered for therapeutic use based on its potent inhibition o f HIV-1 in these cells. We have further examined the effects of IL-13 on alveolar macrophages under conditions that reflect those seen in ac quired immune deficiency syndrome, where this cell type is often infec ted by the opportunistic pathogen human cytomegalovirus (HCMV). Alveol ar macrophages exposed to both HCMV and HIV-1 consistently exhibited h igher levels of HIV-1 replication than cells exposed to HIV-1 alone, H IV-1 production was strongly suppressed in alveolar macrophages treate d with IL-13 regardless of whether or not the cultures were coinfected with HCMV. However, IL-13 treatment markedly enhanced the expression of HCMV in otherwise latently infected macrophages in a dose dependent manner, These unexpected differential effects of IL-13 on host-virus interactions are important considerations in guiding its potential the rapeutic applications. (C) 1997 by The American Society of Hematology.