Mapping and restriction of a dominant viral CD4 + T cell core epitope by both MHC class I and MHC class II

Abstract

Virus-specific CD4 + T cells contribute to effective virus control through a multiplicity of mechanisms including direct effector functions as well as “help” for B cell and CD8 + T cell responses. Here, we have used the lymphocytic choriomeningitis virus (LCMV) system to assess the minimal constraints of a dominant antiviral CD4 + T cell response. We report that the core epitope derived from the LCMV glycoprotein (GP) is 11 amino acids in length and provides optimal recognition by epitope-specific CD4 + T cells. Surprisingly, this epitope is also recognized by LCMV-specific CD8 + T cells and thus constitutes a unique viral determinant with dual MHC class I- and II-restriction.