Multiple sclerosis (MS) is a chronic debilitating disease of the central nervous system primarily mediated by T lymphocytes with specificity to neuronal antigens in genetically susceptible individuals. On the other hand, myasthenia gravis (MG) primarily involves destruction of the neuromuscular junction by antibodies specific to the acetylcholine receptor. Both autoimmune diseases are thought to result from loss of self-tolerance, which allows for the development and function of autoreactive lymphocytes. Although the mechanisms underlying compromised self-tolerance in these and other autoimmune diseases have not been fully elucidated, one possibility is numerical, functional, and/or migratory deficits in T regulatory cells (Tregs). Tregs are thought to play a critical role in the maintenance of peripheral immune tolerance. It is believed that Tregs function by suppressing the effector CD4+ T cell subsets that mediate autoimmune responses. Dysregulation of suppressive and migratory markers on Tregs have been linked to the pathogenesis of both MS and MG. For example, genetic abnormalities have been found in Treg suppressive markers CTLA-4 and CD25, while others have shown a decreased expression of FoxP3 and IL-10. Furthermore, elevated levels of pro-inflammatory cytokines such as IL-6, IL-17, and IFN-γ secreted by T effectors have been noted in MS and MG patients. This review provides several strategies of treatment which have been shown to be effective or are proposed as potential therapies to restore the function of various Treg subsets including Tr1, iTr35, nTregs, and iTregs. Strategies focusing on enhancing the Treg function find importance in cytokines TGF-β, IDO, interleukins 10, 27, and 35, and ligands Jagged-1 and OX40L. Likewise, strategies which affect Treg migration involve chemokines CCL17 and CXCL11. In pre-clinical animal models of experimental autoimmune encephalomyelitis (EAE) and experimental autoimmune myasthenia gravis (EAMG), several strategies have been shown to ameliorate the disease and thus appear promising for treating patients with MS or MG.

Improvement over current methods of beta cell viability assessment is highly warranted in order to efficiently predict the viability and function of beta cells prior to transplantation into type 1 diabetes patients. Dispersed human islet cells were stained with the cell‐permeable zinc‐selective dye, FluoZin‐3‐AM, along with the mitochondrial membrane potential indicator [(tetramethylrhodamine ethylester (TMRE)] and the thiol‐binding dye, monochlorobimane (mBcl), and analyzed by flow cytometry. Islets were subjected to various experimental conditions to validate the usefulness of this method to accurately determine the viability and function of beta cells. Staining with FluoZin‐3 revealed the presence of higher amounts of chelatable zinc ions in beta cells than in lymphoid cells and fibroblasts. An intracellular zinc chelator competitively inhibited the binding of FluoZin‐3 to zinc ions. Mitochondrial depolarization or oxidative stress minimally affected the binding of mBcl and FluoZin‐3, respectively, to thiols and zinc ions. The combination of FluoZin‐3, TMRE, and mBcl was sufficient and necessary for the determination of the viability and function of beta cells. The data demonstrate the usefulness of the zinc‐specific dye and the indicators of mitochondrial function and thiol levels, to accurately estimate the beta cell viability and function. This novel flow cytometry method has implications for islet transplantation in type 1 diabetes patients. © 2008 International Society for Analytical Cytology.