Mesenchymal Stem Cells — Their Antimicrobial Effects and Their Promising Future Role as Novel Therapies of Infectious Complications in High Risk Patients

The Rising Role of Mesenchymal Stem Cells in the Treatment of Various Infectious Complications

“…MSCs have immunomodulatory and immunosuppressive properties that enable them to have several therapeutic and clinical applications including: hematopoietic stem cell transplantation (HSCT), autoimmune disorders, regenerative medicine and tissue repair, neurological diseases, bone and cartilage disorders, as well as treatment of several infections and acute respiratory distress syndrome (ARDS). Details are shown in Table 3 [1,2,6,8,[25][26][27][28][29]. MSCs are major constituents of the BM microenvironment and the HSC niche and apparently they are the masters of survival and clonality [30][31][32].…”

“…The putative roles of BM-MSCs during infection are: (1) detection of pathogens, (2) activation of host immune responses, (3) elimination of pathogens, (4) induction of proinflammatory gradients, and (5) modulation of proinflammatory host immune response due to having specific immunoregulatory properties of MSCs including: inhibition of differentiation of monocytes to dendritic cells (DCs), alteration of cytokine profile of DCs, induction of tolerant phenotypes of naïve and effector T-cells, inhibition of antibody production by B-cells, and suppression of natural killer (NK) cell proliferation and NK-mediated cytotoxicity [1,2,28,34]. BM-MSCs may augment antimicrobial responses, abridge proinflammatory and damage responses, and ameliorate associated tissue injury and they appear to function as a critical fulcrum providing balance by promoting pathogen clearance during the initial inflammatory response, and suppressing inflammation to preserve integrity of the host and facilitate tissue repair [1,2,34].…”

“…BM-MSCs may protect against infectious challenge by direct effects on the pathogens or through indirect effects on the host [1]. However, placenta-derived MSCs and fetal membrane-derived MSCs are highly susceptible to herpes viruses including varicella zoster virus (VZV) [2,38]. Several types of stem cells including BM-MSCs and neural stem cells can cross the blood brain barrier and reach not only brain tumors but also ischemic and injured tissues caused by certain infections in the brain and engraft there.…”

“…Mesenchymal stem cells (MSCs), which were first described by Alexander Fridenstein in the 1960s, are heterogeneous, non-hematopoietic, adult multipotent stromal progenitor cells that are capable of self-renewal as well as differentiation into multiple lineages and various cell types [1][2][3][4][5][6][7][8]. They can be isolated from several sources including bone marrow (BM), peripheral blood (PB), umbilical cord blood (UCB), amniotic fluid, placenta, adipose tissue (AT), and dental pulp as shown in Table 1 [1][2][3][4][5][6][7][8]. Although the BM is the main source of MSCs, these stromal cells constitute only a small fraction of the total number of cells populating the BM [2,[4][5][6].…”

“…They can be isolated from several sources including bone marrow (BM), peripheral blood (PB), umbilical cord blood (UCB), amniotic fluid, placenta, adipose tissue (AT), and dental pulp as shown in Table 1 [1][2][3][4][5][6][7][8]. Although the BM is the main source of MSCs, these stromal cells constitute only a small fraction of the total number of cells populating the BM [2,[4][5][6]. markers: CD 45, CD 34, CD 11b, CD 14, CD 19, CD 79a, and HLA-DR.…”