CD40/CD40L interactions and cytokines regulate HIV replication in B cells in vitro.

Using our in vitro model of normal B cell infection, we investigated whether cellular interactions and/or cytokines directing the B cell response also regulate HIV replication. Phorbol esters and CD40 Ab plus IL4, added prior to infection, substantially increased subsequent viral replication. Postinfection, IL2 with or without IL4 and, to a lesser extent, CD40/CD40L interactions enhanced viral replication. In contrast, IL10 down-regulated HIV replication induced by cytokines, without affecting spontaneous or CD40 Ab-induced replication. Both enhancing and inhibitory effects of cytokines on viral replication were independent of their ability to modulate B cell proliferation. Thus, these two phenomena seem to be independently regulated in human B cells.