Immune system via paracrine factors and cell-contact molecules

The term 'Immune system via paracrine factors and cell-contact molecules' describes a complex physiological mechanism of immunomodulation rather than a single molecular target. This process is most notably associated with Mesenchymal Stem Cells (MSCs), which regulate the activity of T cells, B cells, and natural killer cells through two distinct but complementary pathways (Gao et al., 2016, 'Mesenchymal stem cells: a new strategy for immunosuppression'). The paracrine component involves the secretion of soluble factors such as Interleukin-10 (IL-10), Transforming Growth Factor-beta (TGF-β), and Indoleamine 2,3-dioxygenase (IDO), which create a suppressive chemical environment (Kyurkchiev et al., 2014, 'Secretion of immunomodulatory factors by mesenchymal stem cells'). Simultaneously, cell-contact molecules like PD-L1 and Fas ligand (FasL) interact directly with receptors on immune cells to trigger inhibitory signaling or apoptosis (Wang et al., 2014, 'Mesenchymal stem cells: immunomodulatory mechanisms and clinical applications'). While these pathways are critical for treating conditions like Graft-versus-Host Disease (GvHD) and autoimmune disorders, the entry is considered 'incorrect' as a target because it encompasses an entire system of diverse proteins and interactions rather than a specific, druggable molecule.

Other names

MSC-mediated immunomodulationParacrine and juxtacrine immune regulationCell-mediated immune suppressionStem cell immunomodulatory secretome

Modulation of the immune microenvironment through the simultaneous secretion of soluble anti-inflammatory mediators (paracrine) and direct physical interaction between cell-surface ligands and immune cell receptors (juxtacrine).