Immune system via paracrine factors and cell-cell contact

The immune system via paracrine factors and cell-cell contact describes the dual modalities of communication used by leukocytes to coordinate host defense and maintain self-tolerance. Paracrine signaling involves the secretion of soluble mediators, such as cytokines and chemokines, which bind to receptors on adjacent cells to initiate signaling cascades (NIH, 2023). Cell-cell contact, or juxtacrine signaling, requires direct physical interaction between surface molecules, exemplified by the immunological synapse where T-cell receptors engage MHC-peptide complexes (Nature Reviews Immunology, 2018). These mechanisms are critical in the tumor microenvironment, where cancer cells often exploit cell-cell contact (e.g., PD-L1) or paracrine factors (e.g., TGF-beta) to suppress immune surveillance (PubMed, 2021). While this entry encompasses a broad range of biological processes, therapeutic agents typically target specific nodes within these networks, such as monoclonal antibodies that neutralize cytokines or inhibitors that block checkpoint receptors (StatPearls, 2023). Consequently, this term represents a physiological framework rather than a single druggable molecular target.

Other names

Immune cell communicationParacrine and juxtacrine immune signalingImmune synapse and secretomeIntercellular immune signaling

Modulation of immune signaling through the inhibition or activation of specific cytokines (paracrine) or membrane-bound checkpoint receptors and ligands (cell-cell contact).