Human Regulatory Macrophages Derived from THP-1 Cells Using Arginylglycylaspartic Acid and Vitamin D3

Abstract

Regulatory macrophages (Mregs) are unique in that they have anti-inflammatory and immunosuppressive properties. Thus, treating inflammatory diseases using Mregs is an area of active research. Human Mregs are usually generated by culturing peripheral blood monocytes stimulated using a macrophage colony-stimulating factor with interferon (IFN)-γ. Herein, we generated Mregs with an elongated cell morphology from THP-1 cells that were stimulated with phorbol 12-myristate 13-acetate and cultured with both arginylglycylaspartic acid and vitamin D3. These Mregs regulated macrophage function, and respectively downregulated and upregulated the expression of pro-inflammatory and immunosuppressive mediators. They also expressed Mregs-specific markers, such as dehydrogenase/reductase 9, even when exposed to such inflammatory stimulants as IFN-γ, lipopolysaccharide, purified xenogeneic antigen, and xenogeneic cells. The Mregs also exerted anti-inflammatory and anticoagulatory actions in response to xenogeneic cells, as well as exerting immunosuppressive effects on mitogen-induced Jurkat T-cell proliferation. Our method of generating functional Mregs in vitro without cytokines is simple and cost-effective.

Redefining vascular repair: revealing cellular responses on PEUU—gelatin electrospun vascular grafts for endothelialization and immune responses on in vitro models

“…To further support these findings, gene expression analysis (Figure 14E) and cytokine panel analysis (Figure 14F) for M1/ M2 were performed on days 3 and 7 (Sharma et al, 2007;Wu et al, 2021;Pham et al, 2023).…”

“…Both these trends, along with the M1/M2 polarization Frontiers in Bioengineering and Biotechnology frontiersin.org pattern, suggest inflammation resolution due to the macrostructure and gelatin inclusion in the ML + P + P TEVG. Gelatin, rich in adhesive peptides for cell adhesion, has been linked to a positive stimulus for M2 transformation (Wu et al, 2021;Pham et al, 2023).…”

Regulatory macrophages in solid organ xenotransplantation

“…The first signal is elicited by exposure to M-CSF, granulocyte M-CSF, prostaglandin E2, glucocorticoids, or apoptotic cells [ 81 , 89 ]. The second can be achieved through stimulation with IFN-γ [ 97 - 99 ], IL-10 [ 100 ], or immunosuppressive reagents such as glucocorticoids [ 101 ], vitamin D [ 102 , 103 ], or rapamycin [ 104 ]. The initial signal facilitates the transformation of monocytes into macrophages, while the subsequent signal imparts immunosuppressive characteristics to these cells [ 62 ] ( Fig.…”

“…1 ). Although various methods of Mreg induction have been examined, including our own approach (in which human monocytes were cultured on a three-dimensional micropatterned polydimethylsiloxane surface coated with polydopamine and the common cell adhesion peptide motif arginylglycylaspartic acid [RGD]) [ 105 ], as well as activation with a combination of phorbol 12-myristate 13-acetate, RGD, and vitamin D3 [ 103 ], the most extensively studied method involves combined treatment with M-CSF and IFN-γ. Human Mregs originate from CD14 + peripheral blood monocytes, which are first stimulated with M-CSF for 6 days and then with IFN-γ [ 99 ].…”

“…Although the mechanisms underlying the immunomodulatory functions of Mregs have not been fully elucidated, several have been identified: (1) Mregs secrete anti-inflammatory cytokines, such as IL-10 and TGF-β, which attenuate the proinflammatory response of other immune cells [ 91 ]; (2) Mregs can interact with and promote the development of Tregs, which possess potent suppressive capabilities to regulate immune responses and prevent immune-mediated tissue damage [ 52 , 91 , 103 ]; (3) Mregs undergo specific metabolic reprogramming, shifting their metabolism toward oxidative phosphorylation, a process associated with their anti-inflammatory and tissue-repair capabilities [ 107 , 108 ]; and (4) Mregs engage in cross-talk with other immune cells, such as dendritic cells, T cells, and B cells, thereby influencing their activation and function [ 52 ]. As such, Mregs contribute to a balanced and controlled immune response ( Fig.…”