On Cell Signalling Mechanism of Mycobaterium Leprae Soluble Antigen (MLSA) in Jurkat T Cells

Abstract

We investigated the role of Mycobaterium leprae soluble antigen (MLSA) in the modulation of calcium signalling, phosphorylation of mitogen-activated protein (MAP) kinases and IL-2 mRNA expression in human Jurkat T cells. We observed that MLSA induced an increase in free intracellular calcium concentrations, [Ca2+] i , via opening CRAC (Ca2+-release activated- Ca2+) channels. Furthermore, MLSA failed to potentiate both thapsigargin- and anti-CD3 antibodies-induced capacitative calcium influx in Jurkat T cells. We observed that MLSA failed to affect the degree of phosphorylation of two MAP kinases, i.e., ERK1/ERK2, stimulated by anti-CD3 antibodies alone or phorbol 12-myristate 13-acetate (PMA) alone. In order to mimic co-stimulation of T cells, we stimulated them by both PMA and anti-CD3 antibodies. MLSA significantly curtailed the phosphorylation of ERK1/ERK2, stimulated by both PMA and anti-CD3 antibodies in Jurkat T cells. Also MLSA was found to reduce the transcription of IL-2 gene in PMA plus anti-CD3 antibodies-activated Jurkat T cells. Our finding demonstrates that Ca2+ influx via CRAC channels, inhibition of ERK1/ERK2 phosphorylation and IL-2 gene transcription may be implicated in immunosuppressive effects of MLSA antigen.

DOI: 10.1007/s11010-006-9132-8

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Cite this paper

@article{Joshi2006OnCS, title={On Cell Signalling Mechanism of Mycobaterium Leprae Soluble Antigen (MLSA) in Jurkat T Cells}, author={Beenu Joshi and Sihem Khedouci and Pradeep Dagur and Aziz Hichami and Uttpal Sengupta and Naim A Khan}, journal={Molecular and Cellular Biochemistry}, year={2006}, volume={287}, pages={157-164} }