حسین رضوان

Abstract: Mesenchymal stem cells (MSCs) are non-hematopoietic stem cells with features such as self renew and multilineage differentiation. Modulation of immune responses is one of the characteristics of these cells. Due to the effectiveness of these cells to migrate towards the site of infections, production soluble factors, cell-cell communication mechanisms and releasing extracellular vesicles (EVs) containing immunomodulatory molecules and cytokines are hypothesized to modulate the immune system. The characteristics of innate and acquired immune system regulation are the therapeutic applications of these cells, which include anti-inflammatory, anti-apoptotic, chemotactic and tissue repair stimulator in response to injury. The mechanism of action of MSCs is by using the production of growth factor, enzymes, chemokines and the effect of these factors on the response to the site of damage and the stimulation of progenitor cells for tissue regeneration; such as: inhibiting infiltration of neutrophils, induce a “tolerogenic” phenotype in monocytes, effect on maturation of dendritic cells, stimulation of anti-inflammatory phenotype in macrophages, secretion of programmed death-ligand 1 (PD-L1) and PD L2 in T cells, effect on proliferation, differentiation and chemotactic behavior of B cells for immune mediated disorders, inhibiting proliferation and cytotoxicity of natural killer (NK) cells and regulatory T cells which cause the migration of these cells to the site of infection. MSCs also inhibit NK proliferation through factors such as indoleamine 2,3-dioxygenase (IDO) and prostaglandin E2(PGE2). In recent studies, in addition to examining the effects of these cells on non-infectious complications, the use of mesenchymal stem cells as one of the immunotherapy methods for infectious diseases has been considered. Recent studies have shown new ideas of treatment approaches against infectious agents such as bacteria, viruses, fungal agents and parasites. population of th