MSC: immunoregulatory effects, roles on neutrophils and evolving clinical potentials

Abstract

Mesenchymal stem cells (MSCs) are multipotent, non-hematopoietic stem cells capable of differentiating into varieties of mature cell types such as osteoblasts, chondrocytes, adipocytes, and myoblasts. MSCs can be isolated from different kinds of tissues and cultivated in vitro for amplification and passage easily. These cells have drawn researcher's attention lately due to their ability of tissue repair, properties of hematopoiesis support and function of immunoregulation through the secretion of a variety of cytokines and growth factors that have both paracrine and autocrine activities. MSCs can regulate the proliferation of T cells, the antibodies secretion of B cells, maturation of DC, polarization of macrophages and also have many effects on neutrophils such as the suppression of NO secretion, inhibition of apoptosis, reduction of their infiltration, decreasing of N-Formy l-L-Methionine-L-leucy l-L-phenylalanine, induction of respiratory bursts and promotion of survivals. In some conditions, MSCs exert their function of treatment through immunoregulation. We reviewed the multifaceted roles of MSCs in communicating with immune cells mainly neutrophils in both in vivo and in vitro experiments. MSCs may provide promising trends for cell therapy in future.

Keywords: MSCs; immunoregulation; neutrophils.

Figure 1

The effects of MSC on immune cells. The secretion of IL-6, IL-8 and GM-CSF by MSC increases neutrophil migration to the site of infection/injury, enhancing their activation and phagocytosis whilst promoting their survival. Furthermore, MSC can secrete other cytokines like PGE2, IDO, HGF, CPG, IL-2, IL-4, IL-10, TGF-β1 and so on to affect the proliferation, differentiation, maturation and function of other immune cells such as T cell, B cell, Dendritic cell, Macrophage and NK cell.

Figure 2

The effect of MSCs on neutrophils. Abbreviations: IL-10 (interleukin 10), IL-6 (interleukin 6), IL-8 (interleukin 8), Signal transducer and activator of transcription 3 (STAT3), TNF-stimulated gene 6 protein (TSG-6), CXC receptor 2 (CXCR2).

Figure 3

Distribution of MSC regulation on neutrophils in different diseases.