Surface markers and transendothelial migration of dendritic cells from elderly subjects

Age-related changes of immune functions have been extensively investigated in both humans and animal models; nevertheless, the literature on potential alterations of dendritic cells, potent antigen presenting cells responsibl e for initiating immune responses, with aging is very scarce. We studied th e immuno-phenotype of peripheral blood dendritic cells of elderly and young subjects by three-color flow cytometry. In addition, the capacity of trans endothelial migration, an important step in inflammatory reactions, of peri pheral blood dendritic cells of elderly subjects was investigated in an in vitro model. The expression of HLA-DR in the peripheral blood dendritic cel ls of the elderly subjects was significantly decreased when compared to the young control subjects. The expression of various other surface markers wa s similar in the young and elderly subjects. The ability of transendothelia l migration of dendritic cells was found to be unimpaired in the elderly su bjects. Both in the young and elderly subjects a significantly higher expre ssion of CD29, CD86, HLA-DR, and HLA-DQ in the dendritic cells that had mig rated through the endothelium in comparison to nonadherent, nonmigrating ce lls was found. In the migrating dendritic cells of the elderly subjects a s ignificantly increased expression of CD11c was observed, whereas the expres sion of CD54 was significantly enhanced in the migrating dendritic cells of the young subjects only. In conclusion, our results demonstrate intact fun ctions and a normal immunophenotype of dendritic cells derived from elderly subjects. Dendritic cells thus seem to be functional and therefore are not responsible for the well-known decline of T cell functions with aging. (C) 2000 Elsevier Science Inc. All rights reserved.