Frontiers in Bioscience-Elite (FBE) is published by IMR Press from Volume 13 Issue 2 (2021). Previous articles were published by another publisher on a subscription basis, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Frontiers in Bioscience.
Lymphocytes are reported to express nicotinic acetylcholine receptors (nAChR). However, no data are available on the expression of these nAChR on activated lymphocyte relatively to resting lymphocytes. In this study, we examined nAChR subunits expression in PHA-stimulated versus un-stimulated lymphocytes, and four leukemic cell lines. Cell stimulation with nicotine triggered calcium responses only in some experiments conducted with PHA-stimulated lymphocytes. Likewise, only the Jurkat and HL-60 cell lines displayed calcium waves upon nicotine stimulation, whereas the Raji and CCRF-CEM did not. All responding cells displayed an active form of the nicotinic α-7 nAChR. Indeed, use of 2 different sets of primers for the corresponding mRNA showed that expression of the full-length α-7 subunit mRNA was only present in PHA-stimulated lymphocytes for which calcium waves had been evidenced. Microscopy analysis of lymphocytes structure showed a direct relationship between their size, their α-7 nAChR expression, and calcium release upon nicotine stimulation. Then, this relationship suggested that lymphocytes need a prime activation to express the α-7 nAChR, and therefore to release calcium in response to nicotine.