Chapter 21 : Dynamics of the CD8 T-Cell Response Revealed by Listeria monocytogenes Infection

Abstract:

This chapter discusses the recent advances in understanding of the dynamics of the CD8 T-cell response as revealed by murine infection with Listeria monocytogenes. A number of studies suggest that the magnitude of expansion of the CD8 T-cell population after L. monocytogenes infection depends on the dose of the infecting pathogen. The expansion phase of the CD8 T-cell response after infection occurs in an environment of substantial inflammation. The peak of the CD8 T-cell response occurs approximately 1 week after infection, but the timing of the peak number of antigen specific CD8 T cells can vary by several days depending on the infection model system evaluated. The factors that determine the timing of peak expansion in antigen-specific CD8 T-cell numbers in these different systems are unknown. The expansion in antigen-specific CD8 T-cell numbers is followed by an abrupt transition, during which the number of these cells begins to decrease in all tissues of the host. Recent studies with the L. monocytogenes model system have begun to shed light on the nature of the input signals that program CD8 T-cell contraction. The infection of mice with L. monocytogenes evokes a defined, robust CD8 T-cell response that can be tracked and analyzed using modern immunological methodology. This host-pathogen interaction has provided important information in the understanding of all phases of the CD8 T-cell response, from initiation to expansion, contraction, and memory generation.