High expression of CD38 and MHC class II on CD8 T cells during severe influenza disease reflects bystander activation and trogocytosis

Abstract

Objectives: Although co-expression of CD38 and HLA-DR reflects T-cell activation during viral infections, high and prolonged CD38+HLA-DR+ expression is associated with severe disease. To date, the mechanism underpinning expression of CD38+HLA-DR+ is poorly understood. Methods: We used mouse models of influenza A/H9N2, A/H7N9 and A/H3N2 infection to investigate mechanisms underpinning CD38+MHC-II+ phenotype on CD8+ T cells. To further understand MHC-II trogocytosis on murine CD8+ T cells as well as the significance behind the scenario, we used adoptively transferred transgenic OT-I CD8+ T cells and A/H3N2-SIINKEKL infection. Results: Analysis of influenza-specific immunodominant DbNP366+CD8+ ..