Highly pathological influenza A virus infection is associated with augmented expression of PD-1 by functionally compromised virus-specific CD8 T cells

Abstract

One question that continues to challenge influenza A research is why some strains of virus are so devastating compared to their more mild counterparts.Weapproached this question from an immunological perspective, investigating the CD8+ T cell response in a mouse model system comparing high- and low-pathological influenza virus infections. Our findings reveal that the early (day 0 to 5) viral titer was not the determining factor in the outcome of disease. Instead, increased numbers of antigen-specific CD8+ T cells and elevated effector function on a per-cell basis were found in the low-pathological infection and correlated with reduced illness and latertime- point (day 6 to 10) viral titer. H..