"It has long been recognized that lymphocyte counts in the human peripheral blood vary according to the time of day (15–19). Both CD4+ and CD8+ T cell counts are rhythmic, with peak levels during the night that decline in the morning and stay low during the day. This is true for naive, effector, and memory CD4+ and for naive CD8+ T cell subsets"

#Immunology #CD8Cells #Tcells #Circadian #Lymphocyte #Review

https://journals.aai.org/jimmunol/article/210/1/12/237594/Regulation-of-Cytotoxic-CD8-T-Cells-by-the