Neonatal CD8 T cells are slow to develop into lytic effectors after HSV infection in vivo

Abstract

HSV is an important neonatal pathogen. We defined the kinetics of the primary CTL response to HSV-2 in vivo in neonatal mice. Using a replication-defective HSV-2 virus, we demonstrate that neonates mount a primary HSV-specific CTL effector response in the draining LN, with delayed onset and shortened peak activity, in contrast to the rapid, strong response observed in adult mice. The shortened peak neonatal CTL response is independent of HSV dose and is associated with retarded CD8+ T cell expansion, reduced expansion of HSV-specific tetramer-positive CD8+ T cells and a reduced CD8+ T cell IFN-γ response. Paradoxically, neonatal CD8+ T cells display enhanced non-specific early activation tha..