Activation of calcium (Ca)-dependent protein kinase C in aged mesenteric lymph node T and B cells.
We studied the effects of aging on the activities and translocation of Ca-dependent protein kinase C (PKC) in resting mesenteric lymph node (MLN) T and B cells during the activation process induced by T and B cell mitogens and B cell-stimulatory interleukins, including IL-4, IL-5 and IL-6. The activation process in senescent, resting (high density (HD)) MLN T cells is impaired, when these cells are stimulated with T cell mitogen, Con A. The defect in activation is associated with a reduction in both the new production of inositol-1,4,5-triphosphate (IP3) (an indicator for the production of intracellular free Ca) and the induction of Ca-dependent PKC. In contrast, the activation of the aged B cells with LPS plus/minus interleukins (IL-4, IL-5 and IL-6) is not impaired, being at least associated with a Ca-independent pathway of PKC activation. The elevated IP3 content and total (cytosol plus membrane) PKC activity in both resting T and B cells from aged MLN along with the greater difference in T cells than in B cells suggest that the in vivo Go cell cycle status of these cells may differ from that of the young, involving more in T cells. Finally, the MLN and splenic T cell Ca-dependent and B cell Ca-independent PKC activation do not differ between both age groups.
Kawanishi
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Gut Mucosal Molecular Immunity Laboratory, Department of Medicine, UMDNJ Robert Wood Johnson Medical School, New Brunswick.
D000375:Aging / Q000276:immunology / Q000378:metabolism; D000818:Animals; D001402:B-Lymphocytes / Q000201:enzymology* / Q000276:immunology; D002118:Calcium / Q000378:metabolism; D004789:Enzyme Activation; D015544:Inositol 1,4,5-Trisphosphate / Q000378:metabolism; D007378:Interleukins / Q000494:pharmacology; D008198:Lymph Nodes / Q000166:cytology; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D011493:Protein Kinase C / Q000378:metabolism*; D015290:Second Messenger Systems; D013601:T-Lymphocytes / Q000201:enzymology* / Q000276:immunology
D007378:Interleukins; D015544:Inositol 1,4,5-Trisphosphate; D011493:Protein Kinase C; D002118:Calcium