HIV-INDUCED SYNCYTIA IN PERIPHERAL-BLOOD CELL-CULTURES CRAWL BY EXTENDING GIANT PSEUDOPODS

It was previously demonstrated that HIV-induced syncytia of the immort alized T cell line SupT1 reorganize their cytoskeleton and form a sphe rical supernuclear complex, thus mimicking the organization, polarity, and morphology of a single SupT1 cell. Then, through extension of a s ingle, giant pseudopod, these syncytia, which grow to more than 100 ti mes the volume of a single SupT1 cell, translocate along a substratum. To verify that syncytium motility is not peculiar to the SupT1 cell l ine, we have analyzed the cytoskeletal organization and motile capabil ities of HIV-induced syncytia formed in peripheral blood cell cultures containing more than 90% CD4-positive cells. The results demonstrate that although peripheral blood T cells differ from SupT1 cells in size and morphology, they are continuously motile and translocate along a substratum in a manner quite similar to that of SupT1 cells, and perip heral blood T cell syncytia induced by HIV-1LAI as well as two additio nal clinical isolates translocate by the extension of a giant anterior pseudopod in a fashion indistinguishable from that of HIV-induced Sup T1 syncytia. Together, these results support the generalization that H IV-induced T cell syncytia are motile. (C) 1995 Academic Press, Inc.