Skewed representation of functionally distinct populations of Vγ9Vδ2 T lymphocytes in aging
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- 作者：Re ; Francesca ; Poccia ; Fabrizio ; Donnini ; Alessia ; Bartozzi ; Beatrice ; Bernardini ; Giovanni ; et. al.
- 关键词：Human γ ; δ ; T cells ; Immunosenescence ; Chemokine receptors ; CD27 ; Effector functions
- 刊名：Experimental Gerontology
- 出版年：2005
- 出版时间：January - February, 2005
- 年：2005
- 卷：40
- 期：1-2
- 页码：59-66
- 全文大小：232 K
文摘
We recently demonstrated that numerical and functional alterations of γδ T cells are present in healthy elderly. Here we observed that the decreased absolute number of Vγ9Vδ2 T cells present in old subjects in comparison with young/adult and middle aged donors is due to the reduction of naive and central memory Vγ9Vδ2 T cells bearing CD27 and CCR7 antigens. The proportion of effector/memory Vγ9Vδ2 T cells lacking CD27 or CCR7 markers was significantly increased in the peripheral blood of old subjects in comparison with younger donors. Moreover, the percentage of CD69+ γδ T cells was significantly increased in old subjects in comparison with younger donors after overnight activation, confirming that more effector cells are available in aged people. A functional analysis in young/adult and middle aged donors revealed that effector/memory CD27− Vγ9Vδ2 T cells are increased after 10-days of in vitro colture in the presence of isopentenylpyrophosphate (IPP) and IL-2. In contrast, the IPP+IL-2 mediated differentiation and expansion of CD27− effector/memory cells was absent in old subjects, confirming a lack of naive and central memory cells responding to IL-2. Accordingly, the expansion index of effector/memory CD27− Vγ9Vδ2 T cells was negatively correlated with the donor age. Finally, terminally differentiated Vγ9Vδ2 T cells measured as perforin content after 10-day in vitro expansion showed no age-related difference. These data demonstrated a shift of the circulating γδ T cell population towards CD27− and CCR7− effector T cells in the elderly with the reduction of immature CD27+ and CCR7+ T cell precursors.