%0 Journal Article
%T Adenine Dinucleotide Second Messengers and T-lymphocyte Calcium Signaling
%A Insa M. A. Ernst
%A Ralf Fliegert
%A Andreas H. Guse
%J Frontiers in Immunology
%D 2013
%I Frontiers Media
%R 10.3389/fimmu.2013.00259
%X Calcium signaling is a universal signal transduction mechanism in animal and plant cells. In mammalian T-lymphocytes calcium signaling is essential for activation and re-activation and thus important for a functional immune response. Since many years it has been known that both calcium release from intracellular stores and calcium entry via plasma membrane calcium channels are involved in shaping spatio-temporal calcium signals. Second messengers derived from the adenine dinucleotides NAD and NADP have been implicated in T cell calcium signaling. Nicotinic acid adenine dinucleotide phosphate (NAADP) acts as a very early second messenger upon T cell receptor/CD3 engagement, while cyclic ADP-ribose (cADPR) is mainly involved in sustained partial depletion of the endoplasmic reticulum by stimulating calcium release via ryanodine receptors. Finally, adenosine diphosphoribose (ADPR) a breakdown product of both NAD and cADPR activates a plasma membrane cation channel termed TRPM2 thereby facilitating calcium (and sodium) entry into T cells. Receptor-mediated formation, metabolism, and mode of action of these novel second messengers in T-lymphocytes will be reviewed.
%K calcium signaling
%K T-lymphocyte
%K calcium release
%K nicotinic acid adenine dinucleotide phosphate
%K cyclic ADP-ribose
%K adenosine diphosphoribose
%K TRPM2 cation channels
%K calcium entry
%U http://www.frontiersin.org/Journal/10.3389/fimmu.2013.00259/abstract