Hepatitis C Virus Nonstructural Protein NS3 Binds to Sm-D1, a Small Nuclear Ribonucleoprotein Associated with Autoimmune Disease

This molecular cell study investigated an interaction between the hepatitis C virus NS3 protein and the human Sm-D1 small nuclear ribonucleoprotein. Yeast two-hybrid and deletion experiments identified the glycine-arginine-rich C-terminal region of Sm-D1 as an NS3-binding region. Co-expression also altered Sm-D1 behavior and the intracellular localization of NS3 in cultured cells. The findings concern viral and host-protein biology and a possible connection to autoimmune mechanisms. The paper does not study beta-glucan, monocyte cytokine production, supplementation, or patient outcomes.