Signaling proteins modulate cytokine secretion in innate and adaptative immune responses.

GARCÍA VERÓNICA; CHULUYAN EDUARDO

CYTOKINE & GROWTH FACTOR REVIEWS

ELSEVIER SCI LTD

Año: 2007 vol. 18 p. 85 - 96

1359-6101

Immune cells are modulated through the crosslinking of receptors named ‘‘immunoreceptors’’. Ligation of immunoreceptors by their ligands induces a tyrosine-phosphorylation signal that is essential for cell activation or inhibition. Physiologically, immunoreceptor triggering is not enough for cell activation, and stimulation of co-receptors is necessary for antigen-evoked cytokine production. Thus, signal transduction pathways mediated by proteins that regulate cytokine secretion are critical to achieve an effective immune response of the host, where the balance between positive and negative signaling allows effective immune responses, preventing tolerance and autoimmunity. This review deals with recent studies based on the role of the receptor signaling lymphocytic activation molecule (SLAM), a signaling protein  that modulates cytokine secretion by immune cells, and the transmembrane glycoprotein CD31, which plays multiple roles in cellular signaling events by modulating the balance between inhibitory and stimulatory signals to immune cells. Recent studies have shed light on the ability of these molecules to transmit different signals that regulate the ability of innate and adaptive immune cells to synthesize stimulatory and inhibitory cytokines.