title: CD56+ T cells are increased in kidney transplant patients following cytomegalovirus infection.
abstract: BACKGROUND
  CD56+ T cells previously have been identified as potentially cytotoxic lymphocytes, and relative numbers are increased in some infectious diseases.
  
  
  METHODS
  Relative proportions of CD56+ T cells were measured by flow cytometry in groups of renal transplant patients differing in cytomegalovirus (CMV) status of donor (D) and recipient (R). These measurements were related to episodes of CMV viremia.
  
  
  RESULTS
  Patient groups in which recipients (R+) or donors (D+/R-) were CMV+ had significantly higher proportions of CD56+ T cells (5.11 ± 0.69% and 5.42 ± 1.01%, respectively) than the D-/R- group (1.9 ± 0.35%; P = 0.0018 and 0.017, respectively). In the high-risk D+/R- group, it was found that patients who had post-transplant CMV viremia had higher levels than those who remained CMV negative (9.09 ± 2.34% vs. 3.16 ± 1.22%; P = 0.01). CD56+ T cells from R+ and D+/R- groups had higher proportions of both CD4+ and CD8+ cells than the D-/R- group. When activation markers were examined, some CD56+ T cells from both CMV+ groups had a TEM phenotype, with significantly more expressing CD45RO and NKG2C, and less expressing CD28, CD62L, CD127, and CD161 compared to the D-/R- group. Some CD56+ T cells showed specificity for CMV antigens and similar proportions of CD8+ cells were positive for class I HLA-CMV tetramers containing immunodominant CMV peptides compared to the majority CD56- T cells.
  
  
  CONCLUSIONS
  The results show significant increases in proportions of CD56+ T cells in relation to CMV infection in renal transplant patients and suggest that these cells have a cytotoxic function against CMV-infected cells.
authors.affiliation: Department of Clinical Infection, Microbiology & Immunology, Institute of Infection & Global Health, University of Liverpool, Liverpool, UK.|Applied Medical Sciences College Al-hada, Taif University, Taif, Kingdom of Saudi Arabia.
authors.forename: M
authors.initials: M
authors.lastname: Almehmadi
authors.affiliation: Transplant Unit, Royal Liverpool and Broadgreen University Hospital Trust, Liverpool, UK.
authors.forename: A
authors.initials: A
authors.lastname: Hammad
authors.affiliation: Transplant Unit, Royal Liverpool and Broadgreen University Hospital Trust, Liverpool, UK.
authors.forename: S
authors.initials: S
authors.lastname: Heyworth
authors.affiliation: Transplant Unit, Royal Liverpool and Broadgreen University Hospital Trust, Liverpool, UK.
authors.forename: J
authors.initials: J
authors.lastname: Moberly
authors.affiliation: Transplant Immunology, Royal Liverpool and Broadgreen University Hospital Trust, Liverpool, UK.
authors.forename: D
authors.initials: D
authors.lastname: Middleton
authors.affiliation: Liverpool Specialist Virology Centre, Royal Liverpool and Broadgreen University Hospital Trust, Liverpool, UK.
authors.forename: M J
authors.initials: MJ
authors.lastname: Hopkins
authors.affiliation: Liverpool Specialist Virology Centre, Royal Liverpool and Broadgreen University Hospital Trust, Liverpool, UK.
authors.forename: I J
authors.initials: IJ
authors.lastname: Hart
authors.affiliation: Department of Clinical Infection, Microbiology & Immunology, Institute of Infection & Global Health, University of Liverpool, Liverpool, UK.
authors.forename: S E
authors.initials: SE
authors.lastname: Christmas
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D019002:CD56 Antigen / Q000097:blood*; D003430:Cross-Sectional Studies; D003586:Cytomegalovirus Infections / Q000209:etiology / Q000276:immunology*; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016030:Kidney Transplantation; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000276:immunology*; D013602:T-Lymphocytes, Cytotoxic / Q000378:metabolism*; D014019:Tissue Donors
chemical_list: D015415:Biomarkers; D019002:CD56 Antigen; C522918:NCAM1 protein, human
keywords: CD56; T lymphocytes; cytomegalovirus; kidney transplantation