CD8+ T cells primed in the periphery provide time-bound immune-surveillance to the central nervous system

J Immunol. 2011 Aug 1;187(3):1192-200. doi: 10.4049/jimmunol.1100695. Epub 2011 Jun 29.

Abstract

After vaccination, memory CD8(+) T cells migrate to different organs to mediate immune surveillance. In most nonlymphoid organs, following an infection, CD8(+) T cells differentiate to become long-lived effector-memory cells, thereby providing long-term protection against a secondary infection. In this study, we demonstrated that Ag-specific CD8(+) T cells that migrate to the mouse brain following a systemic Listeria infection do not display markers reminiscent of long-term memory cells. In contrast to spleen and other nonlymphoid organs, none of the CD8(+) T cells in the brain reverted to a memory phenotype, and all of the cells were gradually eliminated. These nonmemory phenotype CD8(+) T cells were found primarily within the choroid plexus, as well as in the cerebrospinal fluid-filled spaces. Entry of these CD8(+) T cells into the brain was governed primarily by CD49d/VCAM-1, with the majority of entry occurring in the first week postinfection. When CD8(+) T cells were injected directly into the brain parenchyma, cells that remained in the brain retained a highly activated (CD69(hi)) phenotype and were gradually lost, whereas those that migrated out to the spleen were CD69(low) and persisted long-term. These results revealed a mechanism of time-bound immune surveillance to the brain by CD8(+) T cells that do not reside in the parenchyma.

MeSH terms

  • Animals
  • Brain / immunology*
  • Brain / microbiology
  • Brain / pathology
  • CD8-Positive T-Lymphocytes / immunology*
  • CD8-Positive T-Lymphocytes / microbiology
  • CD8-Positive T-Lymphocytes / transplantation
  • Cell Movement / immunology
  • Cell Survival / immunology
  • Cells, Cultured
  • Epitopes, T-Lymphocyte / cerebrospinal fluid
  • Epitopes, T-Lymphocyte / immunology
  • Female
  • Immunologic Memory
  • Immunologic Surveillance*
  • Immunophenotyping
  • Listeria monocytogenes / immunology
  • Listeriosis / cerebrospinal fluid*
  • Listeriosis / immunology*
  • Listeriosis / pathology
  • Lymphocyte Activation / immunology*
  • Mice
  • Mice, Inbred C57BL
  • Mice, Transgenic

Substances

  • Epitopes, T-Lymphocyte

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