Increased numbers and functional activity of CD56+ T cells in healthy cytomegalovirus positive subjects. Issue 2 (June 2014)

• Record Type: Journal Article
• Authors: Almehmadi, Mazen; Flanagan, Brian F.; Khan, Naeem; Alomar, Suliman; Christmas, Stephen E.
• Is Part Of: Immunology. Volume 142:Issue 2(2014:Jun.)
• Page Start: 258
• Page End: 268
• Publication Date: 2014-06
• Subjects: Immunology -- Periodicals
• DOI: 10.1111/imm.12250
• Languages: English
• ISSNs: 0019-2805

Abstract

<abstract abstract-type="main" id="imm12250-abs-0001"> <title>Summary</title> <p>Human T cells expressing CD56 are capable of tumour cell lysis following activation with interleukin‐2 but their role in viral immunity has been less well studied. Proportions of CD56<sup>+</sup> T cells were found to be highly significantly increased in cytomegalovirus‐seropositive (CMV<sup>+</sup>) compared with seronegative (CMV<sup>−</sup>) healthy subjects (9·1 ± 1·5% versus 3·7 ± 1·0%; <italic>P</italic> < 0·0001). Proportions of CD56<sup>+</sup> T cells expressing CD28, CD62L, CD127, CD161 and CCR7 were significantly lower in CMV<sup>+</sup> than CMV<sup>−</sup> subjects but those expressing CD4, CD8, CD45RO, CD57, CD58, CD94 and NKG2C were significantly increased (<italic>P</italic> < 0·05), some having the phenotype of T effector memory cells. Levels of pro‐inflammatory cytokines and CD107a were significantly higher in CD56<sup>+</sup> T cells from CMV<sup>+</sup> than CMV<sup>−</sup> subjects following stimulation with CMV antigens. This also resulted in higher levels of proliferation in CD56<sup>+</sup> T cells from CMV<sup>+</sup> than CMV<sup>−</sup> subjects. Using Class I HLA pentamers, it was found that CD56<sup>+</sup> T cells from CMV<sup>+</sup> subjects contained similar proportions of antigen‐specific CD8<sup>+</sup> T cells to CD56<sup>−</sup> T cells in donors of several different HLA types. These differences may reflect the expansion and enhanced functional activity of CMV‐specific CD56<sup>+</sup> memory T cells. In view of the link between CD56 expression and T‐cell cytotoxic function, this strongly implicates CD56<sup>+</sup> T cells as being an important component of the cytotoxic T‐cell response to CMV in healthy carriers.</p> </abstract>