Circadian variations of human lymphocytes are not responsible for contradictory or variable results in studies of IL-2 production.
Efforts to correlate various immunological disorders with alterations in IL-2 production in vitro have led to highly variable and often contradictory results. One possible contributing factor to these results could be the existence of circadian variations in the capacity of lymphocytes to produce IL-2 in culture. Although there were reasons to suspect that such variations might exist, the present study revealed no significant variations in 6 of 10 normal subjects in three experiments or in the mean values for all subjects at each of three sample acquisition times. In addition, no subject exhibited circadian variations in all three experiments. Since it was possible that failure to detect variations was due to selection of an inappropriate mitogen or inappropriate culture conditions, 2 mitogens and various culture conditions were used. Circadian variation was noted for only one subject out of eight under only one set of conditions. This suggests that circadian variations are not responsible for variable or contradictory results which have been reported. Therefore, the recently reported circadian variations in T helper to T suppressor ratios do not seem to significantly affect mitogen-induced IL-2 production.
Smith
C
C
Department of Biological Sciences, Mississippi State University, MS 39762.
Pruett
S B
SB
D000328:Adult; D002478:Cells, Cultured; D002940:Circadian Rhythm; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000096:biosynthesis*; D008213:Lymphocyte Activation; D008297:Male; D013601:T-Lymphocytes / Q000378:metabolism*; D006377:T-Lymphocytes, Helper-Inducer / Q000378:metabolism
D007376:Interleukin-2