T-lymphocyte Ca2+ signalling and proliferative responses during sepsis.
Alterations in T-lymphocyte kinetics and/or activation have been implicated in burn and traumatic injury. This study evaluated concanavalin A (Con A) regulation of both intracellular Ca2+ (Ca2+i) and proliferation in T-lymphocytes harvested from spleens of septic rats. Rats were implanted with fecal pellets containing Escherichia coli (150 colony forming units (CFU)) and Bacteroides fragilis (10(4) CFU). T-cell [Ca2+]i was measured before and after treatment of cells with Con A, using Fura-2 and microfluorophotometry. Splenic lymphocytes were cultured for 72 h with Con A to assess their proliferative response. As compared to sterile-implanted rats, the septic rat T-lymphocytes Ca2+i response to ConA significantly decreased on days 1 and 2 after implantation. A significant decrease in T-cell proliferative response to Con A, compared to sterile controls, was found in septic rats on day 2 but not on day 1. These results suggest that Con A-mediated proliferation in T-cells occurs secondarily to a decrease in cellular Ca2+ signalling. The depression in the T-cell proliferative response during sepsis could contribute to a decrease in host's resistance against sepsis.
Choudhry
M A
MA
Department of Physiology, Loyola University of Chicago, Stritch School of Medicine, Maywood, Illinois 60153, USA.
Ahmad
S
S
Thompson
K D
KD
Sayeed
M M
MM
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley; D018805:Sepsis / Q000276:immunology*; D015398:Signal Transduction; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism* / Q000473:pathology
D003208:Concanavalin A; D002118:Calcium