CS1 (CRACC, CD319, SLAMF7) is a member of the Signaling Lymphocyte Activation Molecule family expressed on immune cells mediating host defense. CS1 is a self-ligand and has both activating and inhibitory functions in Natural Killer (NK) cells. However, induction and function of CS1 in human monocytes are currently unknown. The purpose of this study was to evaluate the control of CS1 surface expression in activated monocytes and to assess the effect of CS1 triggering on proinflammatory cytokine production to better understand the role of CS1 in the control of monocyte function. Our study revealed that adherent or LPS-activated monocytes express CS1, and CS1 induction is via NF-κB and PI3K signaling pathways. Importantly, CS1 engagement resulted in reduced production of proinflammatory cytokines TNF-α and IL12p70. Our study implicates that CS1 plays an inhibitory role in human monocytes to control proinflammatory immune responses.
- Copyright © 2013 by The American Association of Immunologists, Inc.