IDO and CD40 May Be Key Molecules for Immunomodulatory Capacity of the Primed Tonsil-Derived Mesenchymal Stem Cells

Abstract

Background: Tonsil-derived mesenchymal stem cells (T-MSCs) were reported to have suppressive effect on T cells, yet much remains unknown about the underlying mechanisms supporting this effect. We investigated the underlying mechanism of the immunomodulatory effect of T-MSCs on immune cell proliferation and cytokine production. Methods: We isolated T-MSCs from human palatine tonsil and evaluated the immunomodulatory capacity using RT-PCR, ELISA, and flow cytometry. Additionally, we assessed the expression of various soluble factors and several costimulatory molecules to detect the priming effect on T-MSCs. Results: T-MSCs significantly inhibited the immune cell proliferation and cytokine expression (TNF-α and IFN-γ) in the direct co-culture, but there was no suppressive effect in indirect co-culture. Additionally, we detected a remarkably higher expression of indoleamine 2,3-dioxygenase (IDO) in the primed T-MSCs having co-expression CD40. Moreover, immune cells or CD4+ T cells showed lower TNF-α, IFN-γ, and IL-4 expression when the primed T-MSC were added; whereas those findings were reversed when the inhibitor for IDO (not IL-4) or CD40 were added. Furthermore, T-bet and GATA3 levels were significantly decreased in the co-cultures of the primed T-MSCs and CD4+ T cells; whereas those findings were reversed when we added the neutralizing anti-CD40 antibody. Conclusions: Primed T-MSCs expressing IDO and CD40 may have immunomodulatory capacity via Th1-mediated and Th2-mediated immune response.

TNF-α and IFN-γ Participate in Improving the Immunoregulatory Capacity of Mesenchymal Stem/Stromal Cells: Importance of Cell–Cell Contact and Extracellular Vesicles

“…In BM-MSC cocultures with enriched CD4+ lymphocyte populations, the generation of CD4+CD25+FoxP3+ lymphocytes involves the participation of TGF-β and PGE2, but direct contact between the two cell types is an indispensable prerequisite [42]. Similar observations have been made in co-cultures with tonsil-derived MSCs (T-MSCs), where cell contact is essential to decrease the proliferation of CD4 T lymphocytes, as well as the differentiation of CD4+TNF-α+ and CD4+IFN-γ+ cells [47]. Likewise, our working group showed that the cell-cell interaction between activated CD3+ T lymphocytes and MSCs derived from BM or umbilical cord blood (UCB) is necessary to increase the expression of cytotoxic T lymphocyte-associated protein 4 (CTLA4), a molecule that is constitutively expressed by Tregs [51].…”

“…In addition, it affects the activation, proliferation, and effector function of T lymphocytes [67,74,77,78], increasing the generation of Treg cells [73] and decreasing the secretion of TNF-α and IFN-γ in activated T lymphocytes [79]. A recent study shows that this last effect is also mediated by CD40, whose expression increases in T-MSCs activated with TNF-α and IFN-γ [47] (Figure 2). It is important to mention that, although PD-L1 is a molecule present in the membrane of MSCs, some studies have suggested that it can also be secreted and that this form is capable of decreasing the expression of CD25 and IL-2 in activated T lymphocytes [78].…”

“…Although regulatory factor secretion plays an important role in the immunoregulatory potential of MSCs, several studies have reported the relevance of direct contact with immune system cells for the development of efficient immunoregulation. Molecules expressed in the MSC membrane, such as programmed cell death ligand 1 (PD-L1), human leukocyte antigen-G1 (HLA-G1), CD40, Jagged-1, intercellular adhesion molecule 1 (CD54/ICAM-1), and vascular cell adhesion molecule 1 (VCAM-1), participate in these mechanisms [43][44][45][46][47] (Figure 1). Furthermore, the generation of nanotubes by T lymphocytes to establish contact with MSCs has been reported [48].…”

The immunomodulation–immunogenicity balance of equine Mesenchymal Stem Cells (MSCs) is differentially affected by the immune cell response depending on inflammatory licensing and major histocompatibility complex (MHC) compatibility

“…In addition to MHC complexes, other costimulatory molecules are involved in the antigenic presentation and may have an impact on the immune recognition of MSCs. CD40 plays an important role in allograft rejection ( 49 , 50 ), and its expression in human MSCs may contribute to an effective activation of T cells ( 51 ). Furthermore, the coupling ligand of CD80 to the CD28 receptor is the first signaling pathway necessary for T-cell costimulation and enhances T-cell proliferation and cytokine secretion ( 51 ).…”

Effect of Airborne Particulate Matter on the Immunologic Characteristics of Chronic Rhinosinusitis with Nasal Polyps

“…Tonsils obtained by tonsillectomy were manually cut into small pieces and exposed to the enzymes, DNase I, and collagenase type I (Sigma-Aldrich) for 30 min at 37 • C under stirring [35]. This solution was then filtered through a 70 µm cell strainer to collect single-cell suspensions.…”