title: Changes in the expression of CD31 and CXCR3 in CD4+ naïve T cells in elderly persons.
abstract: So far, very few studies exist on the naïve T cell population of elderly persons. Only recently an increase in the percentage of long lived CD4(+)CD31(-) naïve T cells has been claimed to occur with aging. We, therefore, characterised CD31(+) and CD31(-) CD45RA(+) CD4(+) T cells in young and healthy elderly persons. The production of IL-2 and IFN-gamma by the different subpopulations was studied following stimulation with PMA and Ionomycin. The expression of CD28, CD11a, CD62L, CXCR3 and CCR7 was also analysed. The results of this study demonstrate a pronounced increase in the percentage of CD31(-) CD45RA(+) T cells within the CD4 subpopulation of elderly persons. Both, CD31(-) and CD31(+) CD45RA(+) cells expressed CD28, CD62L, were CD11a (dim) and produced IL-2 but no IFN-gamma. This phenotype confirms that they were naïve T cells. IL-2 production by naïve T cells was not impaired in elderly persons. Interestingly, CD31(+) as well as CD31(-) naïve T cells contained a subpopulation of CXCR3(+) cells in elderly individuals, but not in young ones. In spite of expressing this chemokine receptor that enables the cells to migrate into inflammatory tissues, they were still CCR7(+) and CD62L(+). We speculate that due to previous contact with local environmental factors, this subset of naïve T cells acquires a different chemokine receptor phenotype, resulting in an altered migratory capacity in old age. Aberrant contact with antigen and effector cell differentiation in unorthodox locations may be the consequence. This could also affect Th1/Th2 polarisation, which is known to be impaired in elderly persons.
authors.affiliation: Institute for Biomedical Aging Research, Austrian Academy of Sciences, Peter Mayr Strasse 4b, A-6020, Innsbruck, Austria.
authors.forename: I
authors.initials: I
authors.lastname: Gomez
authors.forename: U
authors.initials: U
authors.lastname: Hainz
authors.forename: B
authors.initials: B
authors.lastname: Jenewein
authors.forename: S
authors.initials: S
authors.lastname: Schwaiger
authors.forename: A M
authors.initials: AM
authors.lastname: Wolf
authors.forename: B
authors.initials: B
authors.lastname: Grubeck-Loebenstein
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000276:immunology*; D015415:Biomarkers; D015704:CD4 Antigens / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000166:cytology / Q000378:metabolism*; D002448:Cell Adhesion / Q000276:immunology; D002465:Cell Movement / Q000276:immunology; D015331:Cohort Studies; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D017493:Leukocyte Common Antigens / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism*; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine / Q000378:metabolism*; D018417:Th1 Cells / Q000166:cytology / Q000378:metabolism; D018418:Th2 Cells / Q000166:cytology / Q000378:metabolism
chemical_list: D015415:Biomarkers; D015704:CD4 Antigens; C515187:CXCR3 protein, human; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D054367:Receptors, CXCR3; D019707:Receptors, Chemokine; D017493:Leukocyte Common Antigens