Biomedical subjects

Rafael Solana

Publications and source records attributed to Rafael Solana.

20 records · Page 2Linked to original sources

PubMedDate not supplied

Valpha24+ NKT cells are decreased in elderly humans.

Natural killer T (NKT) cells represent a novel cell lineage characterized by the restricted expression of an invariant TCRalpha chain encoded by Valpha24/JalphaQ gene segments in humans and Valpha14/Jalpha281+ in mice. Different aspects of the immune response are severely affected by age. Thus, we have studied the effect of aging on NKT cells from healthy elderly individuals. Our results demonstrated a decreased percentage of CD3+Valpha24+ cells in peripheral blood from elderly donors, whereas mainstream T lymphocytes showed an age-associated decrease in the expression of CD28, the vast majority of CD3+Valpha24+ cells from old individuals were CD28+. A significant increase in the percentage of Valpha24+ cells with the CD4-CD8+ phenotype was also found in the elderly, indicating a redistribution of Valpha24+ subsets according to the CD4/CD8 phenotype. Given the important immunoregulatory role of these cells, the decrease of NKT cells will contribute to the deleterious immune response in the elderly.

Adult↗

PubMedDate not supplied

Human CD4+ T cell clone longevity in tissue culture: lack of influence of donor age or cell origin.

CD4+ human T cell clones were derived from activated peripheral blood lymphocytes of healthy young adults to establish cloning efficiencies (CE) and clonal longevities. These results were compared with those obtained using cells from the very elderly, also in excellent health. CE and both maximal and average longevities under appropriate culture conditions were very similar in the two groups. Moreover, CE of CD34+ hematopoietic progenitor cells and longevities of clones derived from them were also similar. Finally, CE and longevities of clones derived from a patient with chronic myelogenous leukaemia were found to be comparable as well. Hence, T cells with absolutely no antigenic exposure in vivo prior to cloning (i.e. CD34-derived) and those potentially exposed to chronic antigenic stimulation (CML-derived) and those from young or old donors all had similar cloning and propagation properties in vitro. These results imply that the longevity of T cells in culture is more likely to be dictated by cloning conditions than any intrinsic differences between the cells studied.

Adult↗