INTERACTION OF HUMAN PLASMA FIBRONECTIN WITH VIRAL-PROTEINS OF HUMAN-IMMUNODEFICIENCY-VIRUS

Fibronectin (FN) is present in soluble and matrix forms in various bod y fluids and tissues, and has been shown to bind to several pathogens, including viruses. The interaction of FN with viral proteins of human immunodeficiency virus (HIV-1) was investigated by immunofluorescence technique using a cell line chronically infected with HIV-1 (H9-V). T he results of this study showed that FN binds to HIV-1 infected cells, especially at FN concentration of 5 mu g/ml. In addition, FN-pentapep tide has shown the ability to bind to HIV-1 infected cells. On the oth er hand, preincubation with antibodies against FN abolished the bindin g of FN to HIV-1 infected cells. Finally, FN has shown to bind to HIV- 1 glycoproteins, including gp41 and gp120. In contrast, no binding to HIV-1 core proteins, including p15 and p24, was noted. We suggest that FN, in binding HIV-1 particles, may reduce viremia and thus may be in volved in the clearance of viral proteins from the cells.