Seasonal variation in proliferative response and subpopulations of lymphocytes from mice housed in a constant environment.
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.
Planelles
D
D
Unidad de Immunologia Experimental, Centro de Investigación, Hospital La Fe, Valencia, Spain.
Hernández-Godoy
J
J
Montoro
A
A
Montoro
J
J
González-Molina
A
A
D000818:Animals; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D002940:Circadian Rhythm; D003208:Concanavalin A / Q000494:pharmacology; D004777:Environment; D005260:Female; D005455:Fluorescent Antibody Technique; D006799:Housing, Animal; D008070:Lipopolysaccharides / Q000494:pharmacology; D016131:Lymphocyte Subsets / Q000166:cytology*; D008214:Lymphocytes / Q000166:cytology*; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D010835:Phytohemagglutinins / Q000494:pharmacology; D011043:Pokeweed Mitogens / Q000494:pharmacology; D012621:Seasons; D013154:Spleen / Q000166:cytology / Q000187:drug effects
D008070:Lipopolysaccharides; D010835:Phytohemagglutinins; D011043:Pokeweed Mitogens; D003208:Concanavalin A