Hepatitis C Virus Core Binding Impairs T Cell Activation and Function

Strategic Insights -

Recent research from the University States has demonstrated that the hepatitis C virus (HCV) core binds directly to the T cell surface receptor gC1qR, impairing the activation of Lck and Akt, crucial regulators of T cell function. This binding interaction is specific and results in reduced proliferation of T cells, with CD8+ T cells being more severely affected. The study highlights the importance of understanding the early events of T cell activation and the potential mechanisms by which HCV evades immune detection.

Key Takeaways:

  • The hepatitis C virus core binds directly to the T cell surface receptor gC1qR, impairing the activation of Lck and Akt.
  • The binding affinity constant of core protein for gC1qR is 3.8 x 10^(-7) M.
  • The HCV core associates with the surface of T cells specifically via gC1qR, as this binding is inhibited by the addition of either anti-gC1qR antibody or soluble gC1qR.
  • The specificity of the HCV core-gC1qR interaction is confirmed by reduced core binding on Molt-4 T cells treated with gC1qR-silencing small interfering RNA and enhanced core binding on GPC-16 guinea pig cells transfected with human gC1qR.
  • gC1qR is expressed at higher levels on CD8+ than on CD4+ T cells, resulting in more severe core-induced suppression of the CD8+-T-cell population.
  • Importantly, T-cell receptor-mediated activation of the Src kinases Lck and ZAP-70 but not Fyn and the phosphorylation of Akt are impaired by the HCV core.
  • The binding of HCV core to gC1qR leads to impaired activation of CD8+ T cells, underlying the importance of understanding early events of T cell activation.

Statistics:

  • The binding affinity constant of core protein for gC1qR is 3.8 x 10^(-7) M.
  • CD8+ T cells are more severely affected than CD4+ T cells, with 64-90% reduction in core-induced suppression on CD8+-T-cell population.

Sources:

  • Yao, Z.Q., et al. (2004). Direct binding of hepatitis C virus core to gC1qR on CD4+ and CD8+ T cells leads to impaired activation of Lck and Akt. J Virol, 78(12), 6409-6419.
  • Hahn, Y.S. (2004). Department Microbiology, HSC Box 801386, Charlottesville, VA 22908 USA.
  • American Society for Microbiology. (2004). 1752 N St. NW, Washington, DC 20036-2904 USA.