Seasonal variation in proliferative response and subpopulations of lymphocytes from mice housed in a constant environment

Abstract

A seasonal variation in the proliferative response to mitogens and in the proportion of splenic lymphocyte subpopulations was found in mice housed in a constant environment. The lymphoproliferative responses to T-cell and B-cell mitogens reached maximum values in autumn and summer. Identification of lymphocyte subpopulations by flow cytometry demonstrated that the proportion of T cytotoxic-suppressor (Tcs) lymphocytes was significantly higher in autumn and summer than in spring and winter. However, the proportion of B lymphocytes was significantly lower in spring than in the other three seasons, whereas the proportions of T and T helper (Th) cells did not show any seasonal variation. On the other hand, we observed a significant correlation between the level of mitogenic responsiveness and the proportion of Tcs cells, but not between the former and the proportions of B, T or Th cells. These data suggest that the seasonal variation in murine lymphoproliferative responses may depend on the cyclic changes in the proportion of Tcs lymphocytes; these changes, in turn, may be predetermined by the inherent internal biological rhythms of the animal.

Seasonal variations in inflammatory responses to sepsis and stress in mice*

“…Planelles et al (35) showed that mice housed in a constant environment had seasonally different lymphoproliferative responses of splenic T and B cells to mitogenic stimuli, and the portion of CD8-positive cytotoxic T lymphocytes in the spleen were maximal in autumn and summer and may be predetermined by an inherent internal biological rhythm. But, how could this light-independent rhythm be generated?…”

Modeling month‐season of birth as a risk factor in mouse models of chronic disease: from multiple sclerosis to autoimmune encephalomyelitis

“…Alternatively, distinct mechanisms with the same periodicity may uniquely influence seasonal variation in immunity and reproduction, particularly as immunologic circannual rhythms also persist under controlled conditions in domesticated rats and mice (131)(132)(133)(134)(135)(136)(137)(138). Notwithstanding, our documentation that M-SOB effects in chronic human diseases can be modeled in mice will allow for detailed analysis of mechanisms that are associated with M-SOB effects in not only MS, but numerous other human diseases in which M-SOB impacts disease susceptibility during their lifetime.…”

Evaluation of the precision of intradermal injection of control substances for intradermal testing in clinically normal horses

“…A moderate to high degree of intraand interindividual variation in cell-mediated immune responses has been documented 20,[29][30][31][32][33][34][35] in other species. Analysis of this information suggests that there is a substantial amount of variation in the cell-mediated immune response within and among horses by 24 hours after ID injection of PHA.…”