Enhanced infection of an X4 strain of HIV-1 due to capping and colocalization of CD4 and CXCR4 induced by capsianoside G, a diterpene glycoside

We investigated whether capsianosides, diterpene glycosides, extracted from Capsicum plants could affect human immunodeficiency virus type 1 (HIV-1) i nfection. Significant effect on virus infection in MAGI/CCR5 cells was neit her observed for the X4 virus by capsianosides II, XI, and A, nor for an R5 virus by capsianoside G, Apparent enhancement of X4 HIV-1 infection by cap sianoside G was observed and exclusively related to the usage of the CXCR4 coreceptor, The capsianoside G-treated cells had no change in the expressio n level of CD4, CXCR4, and CCR5, however, colocalization and capping of CD4 and CXCR4, but not of CD4 and CCR5 was observed. Our results suggested tha t capsianoside G enhanced X4 virus infection at the level of viral penetrat ion through the capping and colocalization of receptors needed for infectio n. (C) 2001 Academic Press.