Analysis of valpha24vbeta11 inkt cells in healthy young and elderly individuals

摘要

Natural Killer T (NKT) cells represent a cell lineage characterized by the restricted expression of an invariant TCR-alpha chain encoded by Valpha24/JalphaQ gene segment paired preferentially with the Vbeta11 chain. We have previously shown an age-associated decrease in the number of invariant NKT (iNKT) cells. In this work we compare the phenotype of Valpha24Vbeta11 iNKT cells in healthy young and elderly individuals. The frequency and phenotype of iNKT cells in peripheral blood was analyzed by flow cytometry. Our results confirm the age-associated decrease in the frequency of iNKT cells. The analysis of NK associated markers showed a significant reduction in the expression of NKG2D in iNKT cells from elderly individuals. Most iNKT cells expressed the activating receptor DNAM-1. However, low levels of NCRs and CD94/ NKG2 dimers were observed both in young and elderly donors. In conclusion, the decreased percentage of iNKT cells found in elderly individuals and the decreased expression of NKG2D confirms that these cells do not escape to the immunosenescence process.