Breast milk-derived antigen-specific CD8+ T cells: An extralymphoid effector memory cell population in humans

Academic Article


  • Although mouse studies have demonstrated the presence of an effector memory population in nonlymphoid tissues, the phenotype of human CD8+ T cells present in such compartments has not been characterized. Because of the relatively large number of CD8+ T cells present in breast milk, we were able to characterize the phenotype of this cell population in HIV-infected and uninfected lactating women. CMV, influenza virus, EBV, and HIV-specific CD8+ T cells as measured by the IFN-γ ELISPOT and MHC class I tetramer staining were all present at greater frequencies in breast milk as compared with blood. Furthermore, a greater percentage of the breast milk CD8+ T cells expressed the intestinal homing receptor, CD103, and the mucosal homing receptor CCR9. Breast milk T cells were predominantly CD45RO+HLADR+ and expressed low levels of CD45RA, CD62L, and CCR7 consistent with an effector memory population. Conversely, T cells derived from blood were mainly characterized as central memory cells (CCR7 +CD62L+). These results demonstrate a population of extralymphoid CD8+ T cells with an effector memory phenotype in humans, which could contribute to enhanced local virologic control and the relative lack of HlV transmission via this route.
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    Digital Object Identifier (doi)

    Author List

  • Sabbaj S; Ghosh MK; Edwards BH; Leeth R; Decker WD; Goepfert PA; Aldrovandi GM
  • Start Page

  • 2951
  • End Page

  • 2956
  • Volume

  • 174
  • Issue

  • 5