Breast milk-derived antigen-specific CD8+ T cells: an extralymphoid effector memory cell population in humans.
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-gamma 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 HIV transmission via this route.
Sabbaj
Steffanie
S
Department of Medicine, University of Alabama, Birmingham, AL 35294, USA.
Ghosh
Mrinal K
MK
Edwards
Bradley H
BH
Leeth
Ruth
R
Decker
W Don
WD
Goepfert
Paul A
PA
Aldrovandi
Grace M
GM
D000954:Antigens, Surface / Q000096:biosynthesis / Q000097:blood; D015415:Biomarkers / Q000032:analysis / Q000097:blood; D002454:Cell Differentiation / Q000276:immunology; D003587:Cytomegalovirus / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D018984:Epitopes, T-Lymphocyte / Q000032:analysis* / Q000096:biosynthesis / Q000097:blood; D005260:Female; D015488:HIV Antigens / Q000096:biosynthesis / Q000097:blood; D006801:Humans; D007156:Immunologic Memory; D016130:Immunophenotyping; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D018655:Lymphocyte Count; D008221:Lymphoid Tissue / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D008895:Milk, Human / Q000166:cytology* / Q000276:immunology* / Q000378:metabolism; D016176:T-Lymphocyte Subsets / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000166:cytology / Q000276:immunology* / Q000378:metabolism
D000954:Antigens, Surface; D015415:Biomarkers; D018984:Epitopes, T-Lymphocyte; D015488:HIV Antigens