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Increased numbers and functional activity of CD 56 + T cells in healthy cytomegalovirus positive subjects
Author(s) -
Almehmadi Mazen,
Flanagan Brian F.,
Khan Naeem,
Alomar Suliman,
Christmas Stephen E.
Publication year - 2014
Publication title -
immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.297
H-Index - 133
eISSN - 1365-2567
pISSN - 0019-2805
DOI - 10.1111/imm.12250
Subject(s) - cytotoxic t cell , biology , antigen , t cell , microbiology and biotechnology , immunology , immune system , in vitro , biochemistry
Summary Human T cells expressing CD 56 are capable of tumour cell lysis following activation with interleukin‐2 but their role in viral immunity has been less well studied. Proportions of CD 56 + T cells were found to be highly significantly increased in cytomegalovirus‐seropositive ( CMV + ) compared with seronegative ( CMV − ) healthy subjects (9·1 ± 1·5% versus 3·7 ± 1·0%; P < 0·0001). Proportions of CD 56 + T cells expressing CD 28, CD 62L, CD 127, CD 161 and CCR 7 were significantly lower in CMV + than CMV − subjects but those expressing CD 4, CD 8, CD 45 RO , CD 57, CD 58, CD 94 and NKG 2C were significantly increased ( P < 0·05), some having the phenotype of T effector memory cells. Levels of pro‐inflammatory cytokines and CD 107a were significantly higher in CD 56 + T cells from CMV + than CMV − subjects following stimulation with CMV antigens. This also resulted in higher levels of proliferation in CD 56 + T cells from CMV + than CMV − subjects. Using Class I HLA pentamers, it was found that CD 56 + T cells from CMV + subjects contained similar proportions of antigen‐specific CD 8 + T cells to CD 56 − T cells in donors of several different HLA types. These differences may reflect the expansion and enhanced functional activity of CMV ‐specific CD 56 + memory T cells. In view of the link between CD 56 expression and T‐cell cytotoxic function, this strongly implicates CD 56 + T cells as being an important component of the cytotoxic T‐cell response to CMV in healthy carriers.