Prevention of cyclophosphamide-induced and spontaneous diabetes in NOD mice by syngeneic splenocytes treated with cytotoxic drugs

A Single L/D-Substitution at Q4 of the mInsA2-10 Epitope Prevents Type 1 Diabetes in Humanized NOD Mice

Autoreactive CD8⁺ T cells play an indispensable key role in the destruction of pancreatic islet β-cells and the initiation of type 1 diabetes (T1D). Insulin is an essential β-cell autoantigen in T1D. An HLA-A*0201-restricted epitope of insulin A chain (mInsA_2-10) is an immunodominant ligand for autoreactive CD8⁺ T cells in NOD.β2m^null .HHD mice. Altered peptide ligands (APLs) carrying amino acid substitutions at T cell receptor (TCR) contact positions within an epitope are potential to modulate autoimmune responses via triggering altered TCR signaling. Here, we used a molecular simulation strategy to guide the generation of APL candidates by substitution of L-amino acids with D-amino acids at potential TCR contact residues (positions 4 and 6) of mInsA_2-10, named mInsA_2-10DQ4 and mInsA_2-10DC6, respectively. We found that administration of mInsA_2-10DQ4, but not DC6, significantly suppressed the development of T1D in NOD.β2m^null .HHD mice. Mechanistically, treatment with mInsA_2-10DQ4 not only notably eliminated mInsA_2-10 autoreactive CD8⁺ T cell responses but also prevented the infiltration of CD4⁺ T and CD8⁺ T cells, as well as the inflammatory responses in the pancreas of NOD.β2m^null.HHD mice. This study provides a new strategy for the development of APL vaccines for T1D prevention.

The mechanisms and applications of T cell vaccination for autoimmune diseases: a comprehensive review

Autoimmune diseases (ADs) are a spectrum of diseases originating from loss of immunologic self-tolerance and T cell abnormal autoreactivity, causing organ damage and death. However, the pathogenic mechanism of ADs remains unclear. The current treatments of ADs include nonsteroidal anti-inflammatory drugs (NSAIDS), antimalarials, corticosteroids, immunosuppressive drugs, and biological therapies. With the need to prevent side effects resulting from current treatments and acquire better clinical remission, developing a novel pharmaceutical treatment is extremely urgent. The concept of T cell vaccination (TCV) has been raised as the finding that immunization with attenuated autoreactive T cells is capable of inducing T cell-dependent inhibition of autoimmune responses. TCV may act as an approach to control unwanted adaptive immune response through eliminating the autoreactive T cells. Over the past decades, the effect of TCV has been justified in several animal models of autoimmune diseases including experimental autoimmune encephalomyelitis (EAE), murine autoimmune diabetes in nonobese diabetic (NOD) mice, collagen-induced arthritis (CIA), and so on. Meanwhile, clinical trials of TCV have confirmed the safety and efficacy in corresponding autoimmune diseases ranging from multiple sclerosis (MS) to systemic lupus erythematosus (SLE). This review aims to summarize the ongoing experimental and clinical trials and elucidate possible molecule mechanisms of TCV.

Extracorporeal photopheresis in chronic graft-versus-host disease

Despite significant advances in stem cell manipulation and post-transplant immunosuppression, chronic graft-versus-host disease (cGVHD) remains a cause of major long-term morbidity in survivors of allogeneic stem cell transplantation. Extracorporeal photopheresis (ECP) is a novel therapeutic intervention which has demonstrated efficacy in patients with refractory acute and chronic GVHD. Clinical responses have been reported in skin and visceral GVHD. While the long-term immunomodulatory effects of ECP in cGVHD are unknown, recent studies of patients undergoing a 6- to 12-month course of ECP treatment demonstrated an attenuation of Th1-mediated cytokine secretion by activated T-helper cells, a shift in the DC1/DC2 ratio favoring plasmacytoid rather than monocytoid dendritic cell profiles, and a decrease in antigen responsiveness by dendritic cells. The implications of these immunomodulatory effects of ECP on pathogenesis and clinical outcome remains a fertile area for future research.

Self and non-self antigen in diabetic autoimmunity: molecules and mechanisms

In this article, we have summarized current facts, models and views of the autoimmunity that leads to destruction of insulin-producing beta-cells and consequent Type 1 (insulin-dependent) diabetes mellitus. The presence of strong susceptibility and resistance gene loci distinguishes this condition from other autoimmune disorders, but environmental disease factors must conspire to produce disease. The mapping of most of the genetic risk (or disease resistance) to specific alleles in the major histocompatibility locus (MHC class II) has direct functional implications for our understanding of autoimmunity in diabetes and directly implies that presentation of a likely narrow set of peptides is critical to the development of diabetic autoimmunity. While many core scientific questions remain to be answered, current insight into the disease process is beginning to have direct clinical impact with concerted efforts towards disease prevention or intervention by immunological means. In this process, identification of the critical antigenic epitopes recognized by diabetes-associated T cells has achieved highest priority.