Target HCV NS3 CD4+ Th1 epitope to major histocompatibility complex class II pathway

Area of Science:

• Immunology
• Vaccinology
• Molecular Biology

Background:

• Hepatitis C virus (HCV) infection remains a significant global health concern.
• Current HCV vaccine development faces challenges in eliciting robust T-cell responses.
• Targeting conserved epitopes within viral proteins is a strategy for broad protection.

Purpose of the Study:

• To construct and evaluate a novel plasmid-based vaccine for Hepatitis C Virus (HCV).
• To investigate the endogenous targeting of an HCV T-helper epitope to Major Histocompatibility Complex (MHC) class II molecules.
• To assess the expression, localization, and assembly of the engineered vaccine construct.

Main Methods:

• Construction of a plasmid vaccine incorporating class II-associated invariant chain peptide (CLIP) substitution.
• In vitro expression analysis in COS-7 cell line.
• Co-localization studies with BALB/c mouse MHC class II molecule I-Ad.
• Analysis of molecular aggregation and cell surface transport via exocytosis.

Main Results:

• The plasmid vaccine was efficiently expressed in COS-7 cells.
• The expressed protein co-localized with BALB/c mouse MHC class II molecule I-Ad in the endomembrane system.
• The recombinant invariant chain molecule formed a theoretical nonomer structure with I-Ad and was trafficked to the cell surface.

Conclusions:

• The developed HCV plasmid vaccine demonstrates efficient expression and proper cellular trafficking.
• Endogenous targeting of HCV epitopes to MHC class II molecules is feasible.
• This approach holds potential for advancing HCV vaccine development by inducing T-helper cell responses.