Sphingosine-1-phosphate receptors 2 and 3 reprogram resting human macrophages into M1 phenotype following mycobacteria infection

Mycobacteria tuberculosis (M.tb) the causative agent for tuberculosis has been accredited for a high rate of morbidity and mortality worldwide. The rise in MDR and XDR cases has further created new obstacles in achieving the “End TB Strategy”, which is aimed for 2035. In this article, we have demonstrated the potential of sphingosine-1-phosphate (S1P) analogs in providing an anti-mycobacterial effector response by altering macrophage polarity into M1. Among S1PR1 and S1PR3 analogs, S1PR2 analogs proficiently favor selective polarization of infected human macrophages into M1 phenotypes, marked by increased expression of M1 markers and decreased M2 markers. Furthermore, S1PR1-3 analogs treated macrophages were also able to decrease the secretion of anti-inflammatory cytokine IL-10 and can induce NO secretion in infected macrophages. Lastly, only S1PR2-3 analogs were able to restrict the growth of mycobacteria in human macrophages. Taken together our study reflects the potential of S1PR2-3 analogs in providing host defenses following mycobacterial infection by favoring M1 macrophage polarization.