Physiological functions of mitochondrial Na+-Ca2+ exchanger, NCLX, in lymphocytes.

Roles of mitochondrial Na+-Ca2+ exchanger, NCLX, were studied in B lymphocytes such as heterozygous NCLX knockout DT40 cells, NCLX knockdown A20 cells, and native mouse spleen B lymphocytes treated with a NCLX blocker, CGP-37157. Cytosolic Ca2+ response to B cell receptor stimulation was impaired in these B lymphocytes, demonstrating importance of mitochondria-ER Ca2+ recycling via NCLX and sarco/endoplasmic reticulum Ca2+-ATPase SERCA, and interaction with store-operated Ca2+ entry. NCLX was also associated with motility and chemotaxis of B lymphocyte. Contrary to B lymphocytes, contribution of NCLX in mouse spleen T lymphocytes was minor.