Adoptive Transfer of Immunomodulatory M2 Macrophages Prevents Type 1 Diabetes in NOD Mice

Abstract

Macrophages are multifunctional immune cells that may either drive or modulate disease pathogenesis depending on their activation phenotype. Autoimmune type 1 diabetes (T1D) is a chronic proinflammatory condition characterized by unresolved destruction of pancreatic islets. Adoptive cell transfer of macrophages with immunosuppressive properties represents a novel immunotherapy for treatment of such chronic autoimmune diseases. We used a panel of cytokines and other stimuli to discern the most effective regimen for in vitro induction of immunosuppressive macrophages (M2r) and determined interleukin (IL)-4/IL-10/transforming growth factor-β (TGF-β) to be optimal. M2r cells expressed programmed cell death 1 ligand-2, fragment crystallizable region γ receptor IIb, IL-10, and TGF-β, had a potent deactivating effect on proinflammatory lipopolysaccharide/interferon-γ–stimulated macrophages, and significantly suppressed T-cell proliferation. Clinical therapeutic efficacy was assessed after adoptive transfer in NOD T1D mice, and after a single transfer of M2r macrophages, >80% of treated NOD mice were protected against T1D for at least 3 months, even when transfer was conducted just prior to clinical onset. Fluorescent imaging analyses revealed that adoptively transferred M2r macrophages specifically homed to the inflamed pancreas, promoting β-cell survival. We suggest that M2r macrophage therapy represents a novel intervention that stops ongoing autoimmune T1D and may have relevance in a clinical setting.

Fasting and meal-stimulated residual beta cell function is positively associated with serum concentrations of proinflammatory cytokines and negatively associated with anti-inflammatory and regulatory cytokines in patients with longer term type 1 diabetes

“…Peak expression of anti-inflammatory counterregulatory cytokines may occur prior to the onset of overt diabetes, as seen in the siblings of patients with type 1 diabetes or in animal models [23,27], whereas the diseaserelated production of these cytokines may regress several years after diagnosis of diabetes, as observed here. Previous studies have reported that these anti-inflammatory and regulatory cytokines are able to protect pancreatic beta cells from immune destruction [8,[29][30][31]. The lack of such activity may promote the persistence of the beta cell destructive process in patients with a longer duration of diabetes.…”

Polarization of Macrophages toward M2 Phenotype Is Favored by Reduction in iPLA2β (Group VIA Phospholipase A2)

“…by IL-4 or IL-10) (13). Whereas M1 macrophages are recognized causative factors in T1D development (14), M2 macrophages appear to protect against T1D (15). Recent studies suggest that ROS can modulate macrophage polarization and that reduction in ROS generation promotes an M2 macrophage phenotype, blunts M1 macrophage phenotype, and dramatically delays T1D onset (16).…”

Generation of anti-inflammatory macrophages for implants and regenerative medicine using self-standing release systems with a phenotype-fixing cytokine cocktail formulation

“…Double and triple combinations of anti-inflammatory factors IL4, IL10 and TGFβ1 were previously shown to be more efficient than single cytokines, and induced robust tolerogenic phenotype in mouse and human macrophages [8,9,12]. In addition, macrophages stimulated by such cytokine combinations partially retained anti-inflammatory phenotype in vivo and their adoptive transfer protected mice from chronic inflammatory disorders including autoimmune type 1 diabetes and adriamycin nephrosis [8,9]. In our study, we have utilized triple combination of IL4, IL10 and TGFβ1…”

“…Thus, engineering a microenvironment around implanted devices or artificial tissues that would convert macrophages to a more pro-healing phenotype (generally designated as M2) is a promising approach to improve the integration of the device and attenuate the adverse immune reactions [6,7]. Furthermore, phenotype-controlled macrophages polarized by anti-inflammatory cytokines have previously been used to treat chronic inflammatory conditions and favored implant tolerance in mouse models [1,8,9].…”