Interleukin-13 Pathway Alterations Impair Invariant Natural Killer T-Cell-Mediated Regulation of Effector T Cells in Type 1 Diabetes

An Insulin-Inspired Supramolecular Hydrogel for Prevention of Type 1 Diabetes

Supramolecular peptide hydrogel has shown promising potential in vaccine development largely because of its ability to function both as antigen depot and immune adjuvant. Nap-GdFdFdY, a tetrapeptide hydrogel that has been previously reported to exhibit adjuvant effect, is inadvertently found to contain conserved peptide sequence for insulin, proinsulin, and glutamic acid decarboxylase, 3 major autoantigens for the autoimmune type 1 diabetes (T1D). At present, despite being managed clinically with insulin replacement therapy, T1D remains a major health threat with rapidly increasing incidences, especially in children and young adults, and antigen-specific immune tolerance induction has been proposed as a feasible approach to prevent or delay T1D progression at an early stage. Here, it is reported that innoculation of Nap-GdFdFdY leads to complete protection of nonobese diabetic (NOD) mice from T1D development till the age of 36 weeks. Better maintenance of pancreatic islet morphology with minimal immune cell infiltration is also observed from mice exposed to Nap-GdFdFdY. This beneficial impact is mainly due to its facilitative role on enhancing peripheral T regulatory cell (Treg) population, shown as increased splenic Treg percentage, and function, demonstrated by maintenance of circulating TGF-β1 level. Serum cytokine microarray data further implicate a "buffering" role of Nap-GdFdFdY on systemic inflammatory tone in NOD mice. Thus, with its versatility, applicability, and excellent potency, Nap-GdFdFdY is posited as a novel therapeutic intervention for T1D.

A systematic review on the functional role of Th1/Th2 cytokines in type 2 diabetes and related metabolic complications

The T-helper (Th1/Th2) paradigm is widely studied for its role in modulating an adaptive immune response, especially in relation to the onset of various autoimmune diseases. In fact, emerging evidence clearly shows an inverse relationship between Th1/Th2 cytokines and the development of type 2 diabetes (T2D) complications, which is accelerated by an exacerbated inflammatory state. Here, relevant studies reporting on any association between the levels of Th1/Th2 cytokines and the development of T2D were retrieved through major electronic databases such as The Cochrane Library, Embase and PubMed. Extracted evidence which mostly involved animal models and human subjects with T2D or metabolic syndrome was assessed for quality and risk of bias using the Downs and Black checklist and Animal Research: Reporting of In Vivo Experiments (ARRIVE) guidelines. Results strongly correlated raised Th1/Th2 cytokines such as interferon-gamma (IFN-γ)/interleukin (IL)-5 and IL-2/IL-5 ratios to T2D, and this was positively linked with the other complications including retinopathy and cardiovascular complications. Further, logistic regression analysis demonstrated that the Th1/Th2 ratios were significantly associated with impaired glucose homeostasis, abnormally enhanced lipid profiles, and insulin resistance. Although more studies making use of a larger sample size are required, current data suggest that optimal modulation of Th1/Th2 cytokines may be an important aspect in the management of T2D and its associated complications.

Interleukin-13: A promising therapeutic target for autoimmune disease

Interleukin-13 (IL-13) was previously thought to be a redundant presence of IL-4, but in recent years its role in immunity, inflammation, fibrosis, and allergic diseases has become increasingly prominent. IL-13 can regulate several subtypes of T helper (Th) cells and affect their transformation, including Th1, Th2, T17, etc., thus it may play an important role in immune system. Previous studies have revealed that IL-13 is implicated in the pathogenesis of autoimmune diseases, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), systemic sclerosis (SSc), ulcerative colitis (UC), type 1 diabetes (T1D), sjogren's syndrome (SS), etc. In this review, we will briefly discuss the biological features of IL-13 and summarize recent advances in the role of IL-13 in the development and pathogenesis of autoimmune diseases. This information may provide new perspectives and suggestions for the selection of therapeutic targets for autoimmune diseases.

Intralymphatic Glutamic Acid Decarboxylase-Alum Administration Induced Th2-Like-Specific Immunomodulation in Responder Patients: A Pilot Clinical Trial in Type 1 Diabetes

GAD-alum given into lymph nodes to type 1 diabetes patients participating in an open-label pilot trial resulted in preservation of C-peptide similar to promising results from other trials. Here, we compared the immunomodulatory effect of giving GAD-alum directly into lymph nodes versus that induced by subcutaneous administration. Samples from T1D patients (n = 6) who received 4 μg GAD-alum into lymph nodes (LNs), followed by two booster injections one month apart, and from patients (n = 6) who received two subcutaneous injections (SC) (20 μg) given one month apart were compared. GADA, IA-2A, GADA subclasses, IgE, GAD₆₅-induced cytokines, PBMC proliferation, and T cell markers were analyzed. Lower doses of GAD-alum into LN induced higher GADA levels than SC injections and reduced proliferation and IgG1 GADA subclass, while enhancing IgG2, IgG3, and IgG4. The cytokine profile was dominated by the Th2-associated cytokine IL-13, and GAD₆₅ stimulation induced activated CD4 T cells. Patients responding clinically best account for most of the immunological changes. In contrast, SC treatment resulted in predominant IgG1, predominant IFN-γ, higher proliferation, and activated CD4 and CD8 cells. Patients from the LN group with best metabolic outcome seemed to have common immune correlates related to the treatment. This trial is registered with DIAGNODE (NCT02352974, clinicaltrials.gov) and DIABGAD (NCT01785108, clinicaltrials.gov).

Innate immune cells for immunotherapy of autoimmune and cancer disorders

Modulation of the immune system has been widely targeted for the treatment of several immune-related diseases, such as autoimmune disorders and cancer, due to its crucial role in these pathologies. Current available therapies focus mainly on symptomatic treatment and are often associated with undesirable secondary effects. For several years, remission of disease and subsequently recovery of immune homeostasis has been a major goal for immunotherapy. Most current immunotherapeutic strategies are aimed to inhibit or potentiate directly the adaptive immune response by modulating antibody production and B cell memory, as well as the effector potential and memory of T cells. Although these immunomodulatory approaches have shown some success in the clinic with promising therapeutic potential, they have some limitations related to their effectiveness in disease models and clinical trials, as well as elevated costs. In the recent years, a renewed interest has emerged on targeting innate immune cells for immunotherapy, due to their high plasticity and ability to exert a potent and extremely rapid response, which can influence the outcome of the adaptive immune response. In this review, we discuss the immunomodulatory potential of several innate immune cells, as well as they use for immunotherapy, especially in autoimmunity and cancer.