Type 2 Diabetes: How Much of an Autoimmune Disease?

Abstract

Type 2 diabetes (T2D) is characterized by a progressive status of chronic, low-grade inflammation (LGI) that accompanies the whole trajectory of the disease, from its inception to complication development. Accumulating evidence is disclosing a long list of possible “triggers” of inflammatory responses, many of which are promoted by unhealthy lifestyle choices and advanced age. Diabetic patients show an altered number and function of immune cells, of both innate and acquired immunity. Reactive autoantibodies against islet antigens can be detected in a subpopulation of patients, while emerging data are also suggesting an altered function of specific T lymphocyte populations, including T regulatory (Treg) cells. These observations led to the hypothesis that part of the inflammatory response mounting in T2D is attributable to an autoimmune phenomenon. Here, we review recent data supporting this framework, with a specific focus on both tissue resident and circulating Treg populations. We also propose that selective interception (or expansion) of T cell subsets could be an alternative avenue to dampen inappropriate inflammatory responses without compromising immune responses.

Autoimmune responses and inflammation in type 2 diabetes

“…This has been shown to have adverse effects on insulin production by promoting pancreatic β cell apoptosis 96 . The failure of pancreas to compensate for the insulin demand as the result of β cell apoptosis and pancreatic inflammation causes systemic insulin resistance to develop into T2D 6,97 …”

Overall Reduced Baseline Lymphocyte Subsets Closely Related to the Poor Prognosis and the Disease Severity in Patients With COVID-19 and Diabetes Mellitus

“…The function of speci c T lymphocyte subsets (including T regulatory (Treg) cells) has changed, leading to the following hypothesis: partial in ammation exacerbate T2D autoimmunity. [29]T cells play an important role in promoting or maintaining insulin resistance and in ammation by inducing the production of pro-in ammatory cytokines in metabolic organs (such as pancreas, muscle, adipose tissue and liver). [28,[30][31][32] In adipose tissue the major in ammatory cells was macrophages.…”

In-Silico Study of the Immune Systems Associated Genes in Case of Type-2 Diabetes with Insulin Action and Resistance and in Obesity

“…Diabetes mellitus (DM) and obesity are considered as metabolic disorder related diseases and DM is characterized by hyperglycemia resulting from defects in insulin secretion, insulin action, or both [1,24,25]. The diabetic chronic hyperglycemia is associated with long-term damage, dysfunction, and failure of various organs such as kidneys, eyes, nerves, blood vessels, and heart [1,17,[25][26][27][28][29]. T2D is most often found to be frequent in case of the obese and is characterized by abnormal insulin secretion and/or a decreased sensitivity for insulin which is also known as insulin resistance and results in increased blood glucose levels and T2D is known to be strongly associated with obesity.…”

“…The well-known factors contributing to T2D are age, metabolic syndrome, systematic low-grade inflammation, insulin resistance, islet cell auto-antibodies, beta cell dysfunction, and C-peptide. Some of the factors which promotes inflammation are altered function of specific T lymphocyte cells, B lymphocytes, Th1, and Th17 [17][18][19][20][21]. As mentioned above that T2D is also linked with obesity and these diseases are also the case of metabolic disorder and there exist strong evidences of immune-metabolic connection [10,22,23].…”