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T Makinodan

Publications and source records attributed to T Makinodan.

131 records · Page 8Linked to original sources
PubMedDate not supplied

Nature of the decline in antigen-induced humoral immunity with age.

An attempt has been made to summarize our present knowledge of the influence of age on humoral immunity, as judged by the ability of an individual to generate antibody in response to antigenic stimulation. In general, humoral immunity declines with age, and the onset can occur as early as when an individual reaches sexual maturity. The decline is due to changes in the immune cells and their milieu. Cell loss, shift in the proportion of subpopulations, and qualitative cellular changes have all been detected. The most prominent cellular target of aging appears to be T cells involved in the regulation of humoral response. Since the changes are closely associated with the involution and atrophy of the thymus, an understanding of its changes could be the key to understanding immunosenescence.

Aging↗
PubMedDate not supplied

Suppression of murine natural killer cell activity by adherent cells from aging mice.

Natural killer (NK) cell activity declines with age in mice. The purpose of this study was to investigate the effect of peritoneal and splenic adherent cells from young and old mice on NK activity to determine whether adherent cell suppressor function might contribute to this decline. Peritoneal adherent cells from old mice suppressed NK activity of young splenic non-adherent indicator cells more than peritoneal cells from young mice. Splenic adherent cells from old but not from young mice also suppressed this activity. That (1) the suppressive activity of the adherent cell populations was not affected by treatment with anti-Thy-1 plus complement, and that (2) the adherent cell population contained 77-92% cells positive for alpha-naphthyl acetate esterase activity, suggests that the active adherent suppressor cell may be a macrophage. Therefore, the age-related decline in NK activity in mice can be explained, in part, by an increase in adherent cell suppressor function.

Aging↗
PubMedDate not supplied

Immunological changes in young and old adults during brief laboratory stress.

Few data are available on the response of the human immune system to acute psychological stressors under controlled laboratory conditions. Young female subjects (21-41 years) showed increases in natural killer (NK) cell activity, and in the numbers of circulating CD8 suppressor/cytotoxic T cells, and natural killer lymphocytes following a brief (12 minute) stressful mental arithmetic examination. Older female subjects (65-85 years) failed to show the stress-related increase in NK activity. The psychological stress did lead to increases in the numbers of circulating CD8 suppressor/cytotoxic T cells and NK lymphocytes in old subjects to a similar degree as that seen in the young group. No changes in the numbers of helper/inducer T cells (CD4), total T cells (CD3), or B cells (CD20) were found following the stressor for either group. Cardiovascular, catecholamine, and subjective stress responses were similar for the two age groups. These results demonstrate that brief psychological stress is associated with some rapid immune cell changes, including release of CD8 suppressor/cytotoxic T cells and NK cells into circulation, and in young subjects, increases in NK activity. The absence of an NK activity increase in the older subjects indicates that NK cell mobilization and cell lysis induced by NK cells may be differentially affected by stress. The results also suggest the possibility of an age-related deficit in the up-regulation of NK activity under some environmental demands.

Adult↗