T-cell signaling - effect of age

Age-associated alteration of the immune function is most prominent in the T-cell compartment. The effect of age is observed in the proximal as well as distal events of the T-cell activation pathway. Multiple defects which contribute to the abnormalities in the early phase of the T-cell activation due to aging in humans and/or rodents include progressive expansion of CD28(-) T-cells; impairment of activation of various kinases; relocalization of different enzymes, their substrates and adaptor proteins to the immunological synapses; etc. The contribution of these abnormalities towards the down-regulation of the T-cell activity due to aging has been summarized. (C) 2001 Elsevier Science Inc. All rights reserved.