HCV envelope protein E2 inhibits T cell receptor (TCR)-mediated signaling.

<p>Jurkat control cells (JC) or Jurkat cells stably expressing HCV E2 protein were stimulated with anti-CD3 and anti-CD28. Twenty-four hours later, IL-2 release (A) was measured. Phosphorylation and activation of the lymphocyte specific tyrosine kinase (Lck Y394; B), the zeta-chain-associated protein kinase (ZAP)-70 (Y319; C) and linker for activation of T cells (LAT, Y226; D) was analyzed in HCV E2 expressing Jurkat cells compared to the controls (JC) following TCR activation using anti-CD3. IL-2 released in truncated or substitution mutant HCV E2 proteins expressing Jurkat cells are shown in panel E. The amino acid numbers relate to their location on the HCV polyprotein. Phospho-blots for Lck, ZAP-70 and LAT were performed at least three times with consistent results. Data represent the average of three technical replicates and the standard deviation is shown. Each experiment was independently performed three times with consistent results. *<i>P</i>< 0.01, ns = not significant.