Autor: Toshihiko Kawamura, Chikako Miyaji, Hisami Watanabe, Hiroyuki Nozaki, Toru Abo, Hiromu Toma, Masahiro Minagawa, Yumiko Nohara, Yoshiya Sato
Rok vydání: 1997
Předmět:
Zdroj: Journal of Clinical Immunology. 17:420-429
ISSN: 0271-9142
DOI: 10.1023/a:1027324626199
Popis: The immune system in the aged is a very interesting subject for study. In this study, analysis was extended to extrathymic T cells as well as NK cells and “conventional” T cells (i.e., thymus-derived T cells) in terms of their constitution and function in both healthy and unhealthy centenarians. Middle-aged persons were used as controls. Healthy and unhealthy centenarians showed lower levels in the proportion and absolute number of lymphocytes. The major change in the constitution of lymphocyte subsets was increased levels in the proportion of NK cells (CD56+/CD57+) and extrathymic T cells (CD3+CD57+). Inversely, conventional T cells decreased in proportion and function (i.e., proliferative response to mitogen). Although NK cells increased in centenarians, NK activity by whole lymphocytes and the purified NK fraction decreased. The difference between healthy and unhealthy centenarians was small in all parameters, the only difference being a lower level of expression of CD56 antigens on CD57+ T cells in unhealthy centenarians. These results indicate that there is a major shift in lymphcyte population from conventional T cells to NK cells and extrathymic T cells with aging. Concerning the age-associated increases in CD56+ T and CD57+ T cells, these cells correspond to NK1+ T cells in mice.
Databáze: OpenAIRE
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