Cutting Edge: Effector Memory CD8+ T Cells Play a Prominent Role in Recall Responses to Secondary Viral Infection in the Lung

Abstract

The relative contributions of CD62Lhigh (central) memory and CD62Llow (effector) memory T cell populations to recall responses are poorly understood, especially in the respiratory tract. In this study, we took advantage of a dual-adoptive transfer system in the mouse to simultaneously follow the recall response of effector and central memory subpopulations to intranasal parainfluenza virus infection. Using MHC class I and class II multimers, we tracked the responses of Ag-specific CD8+ and CD4+ memory T cells in the same animals. The data show that effector memory T cells mounted recall responses that were equal to, or greater than, those mounted by central memory T cells. Moreover, effector memory T cells were more efficient at subsequently establishing a second generation of memory T cells. These data contrast with other studies indicating that central memory CD8+ T cells are the prominent contributors to systemic virus infections.