Fig. 4.

Effect of GBV-C on SDF-1 release and CXCR4 surface density. (A) SDF-1 in culture supernatants was measured by ELISA in triplicate on sequential days after removal of doxycycline. There were no differences between VC or parental Jurkat cells; however, SDF-1 increased in Jurkat cells expressing NS5A (t test, P < 0.001 for days 5 and 6). (B) Surface CXCR4 on VC cells or cells stably expressing NS5A was determined by flow cytometry by using isotype control (IC) or anti-CXCR4 antibodies. (C) The effect of adding neutralizing antibody to SDF-1 to cell cultures or isotype control antibody (IC) only partially decreased the HIV-1 inhibitory effect (HIV p24 antigen in culture supernatants 4 days after infection).