Non-obese diabetic or NOD mice, like biobreeding rats, are used as an animal model for type 1 diabetes. [1] Diabetes develops in NOD mice as a result of insulitis, a leukocytic infiltrate of the pancreatic islets. [2] The onset of diabetes is associated with a moderate glycosuria and a non-fasting hyperglycemia. It is recommended to monitor for development of glycosuria from 10 weeks of age; this can be carried out using urine glucose dipsticks. NOD mice will develop spontaneous diabetes when left in a sterile environment. [3] The incidence of spontaneous diabetes in the NOD mouse is 60–80% in females and 20–30% in males. Onset of diabetes also varies between males and females: commonly, onset is delayed in males by several weeks. The mice (as well as C57BL/6 and SJL) are known to carry IgG2c allele. [4] [5]
Non-obese diabetic (NOD) mice exhibit a susceptibility to spontaneous development of autoimmune insulin dependent diabetes mellitus (IDDM). [6] The NOD strain and related strains were developed at Shionogi Research Laboratories in Aburahi, Japan by Makino and colleagues and first reported in 1980. [7] The group developed the NOD strain by an outbreeding of the cataract-prone strain from JcI:ICR mice. [8]
The susceptibility to IDDM is polygenic and environment exerts a strong effect on gene penetrances. Environment including housing conditions, health status, and diet all affect development of diabetes in the mice. For instance, NOD mice maintained in different laboratories can have different levels of incidence. The incidence of disease is linked to the microbiome. [9]
NOD mice are also susceptible to developing other autoimmune syndromes, including autoimmunine sialitis, autoimmune thyroiditis, autoimmune peripheral polyneuropathy etc. Diabetes in these mice can be prevented by a single injection of mycobacterial adjuvants such as complete Freund's adjuvant (FCA) or Bacille de Calmette et Guérin (BCG) vaccine. [10] [11]
Genetic Loci associated with susceptibility to IDDM have been identified in the NOD mouse strain through the development of congenic mouse strains, which have identified several insulin dependent diabetes (Idd) loci. The most important is idd1 which is the major histocompatibility complex class II loci I-Ag7. [12]
NOD mice have polymorphisms in the Idd3 locus which are linked to IL-2 production. IL-2 promotes either immunity or tolerance in a concentration dependent fashion by acting on T helper cells, CTL and NK cells. Low amounts of IL-2 may be needed to promote survival of Treg in mice. Loss of IL-2 can thereby contribute to the development of autoimmunity in NOD mice. [13]
NOD mice have a mutation in exon 2 of the CTLA-4 gene, which causes it to be spliced incorrectly. CTLA-4 plays a major role in suppressing the T-cell immune response. Without the proper functioning of CTLA-4, T-cells attack the insulin producing cells. This results in Type 1 Diabetes. [14]
Beta cells (β-cells), are specialized endocrine cells located within the pancreatic islets of Langerhans responsible for the production and release of insulin and amylin. Constituting ~50–70% of cells in human islets, beta cells play a vital role in maintaining blood glucose levels.Problems with beta cells can lead to disorders such as diabetes.
Lipopolysaccharides (LPS) are large molecules consisting of a lipid and a polysaccharide that are bacterial toxins. They are composed of an O-antigen, an outer core, and an inner core all joined by covalent bonds, and are found in the outer membrane of Gram-negative bacteria, such as E. coli and Salmonella. Today, the term endotoxin is often used synonymously with LPS, although there are a few endotoxins that are not related to LPS, such as the so-called delta endotoxin proteins produced by Bacillus thuringiensis.
Denise Louise Faustman is an American physician and medical researcher. An associate professor of medicine at Harvard University and director of the Immunobiology Laboratory at Massachusetts General Hospital, her work specializes in diabetes mellitus type 1 and other autoimmune diseases. She has worked at Massachusetts General Hospital in Boston since 1985.
Cytotoxic T-lymphocyte associated protein 4, (CTLA-4) also known as CD152, is a protein receptor that functions as an immune checkpoint and downregulates immune responses. CTLA-4 is constitutively expressed in regulatory T cells but only upregulated in conventional T cells after activation – a phenomenon which is particularly notable in cancers. It acts as an "off" switch when bound to CD80 or CD86 on the surface of antigen-presenting cells. It is encoded by the gene CTLA4 in humans.
Type 1 diabetes (T1D), formerly known as juvenile diabetes, is an autoimmune disease that originates when cells that make insulin are destroyed by the immune system. Insulin is a hormone required for the cells to use blood sugar for energy and it helps regulate glucose levels in the bloodstream. Before treatment this results in high blood sugar levels in the body. The common symptoms of this elevated blood sugar are frequent urination, increased thirst, increased hunger, weight loss, and other serious complications. Additional symptoms may include blurry vision, tiredness, and slow wound healing. Symptoms typically develop over a short period of time, often a matter of weeks if not months.
Slowly evolving immune-mediated diabetes, or latent autoimmune diabetes in adults (LADA), is a form of diabetes that exhibits clinical features similar to both type 1 diabetes (T1D) and type 2 diabetes (T2D), and is sometimes referred to as type 1.5 diabetes. It is an autoimmune form of diabetes, similar to T1D, but patients with LADA often show insulin resistance, similar to T2D, and share some risk factors for the disease with T2D. Studies have shown that LADA patients have certain types of antibodies against the insulin-producing cells, and that these cells stop producing insulin more slowly than in T1D patients.
Immune tolerance, or immunological tolerance, or immunotolerance, is a state of unresponsiveness of the immune system to substances or tissue that would otherwise have the capacity to elicit an immune response in a given organism. It is induced by prior exposure to that specific antigen and contrasts with conventional immune-mediated elimination of foreign antigens. Tolerance is classified into central tolerance or peripheral tolerance depending on where the state is originally induced—in the thymus and bone marrow (central) or in other tissues and lymph nodes (peripheral). The mechanisms by which these forms of tolerance are established are distinct, but the resulting effect is similar.
Biobreeding rat, also known as the BB or BBDP rat, is an inbred laboratory rat strain that spontaneously develops autoimmune Type 1 Diabetes. Like the NOD mice, BB rats are used as an animal model for Type 1 diabetes. The strain re-capitulates many of the features of human type 1 diabetes, and has contributed greatly to the research of T1D pathogenesis.
Certain sites of the mammalian body have immune privilege, meaning they are able to tolerate the introduction of antigens without eliciting an inflammatory immune response. Tissue grafts are normally recognised as foreign antigens by the body and attacked by the immune system. However, in immune privileged sites, tissue grafts can survive for extended periods of time without rejection occurring. Immunologically privileged sites include:
Programmed death-ligand 1 (PD-L1) also known as cluster of differentiation 274 (CD274) or B7 homolog 1 (B7-H1) is a protein that in humans is encoded by the CD274 gene.
Free fatty acid receptor 1 (FFAR1), also known as G-protein coupled receptor 40 (GPR40), is a rhodopsin-like G-protein coupled receptor that is coded by the FFAR1 gene. This gene is located on the short arm of chromosome 19 at position 13.12. G protein-coupled receptors reside on their parent cells' surface membranes, bind any one of the specific set of ligands that they recognize, and thereby are activated to trigger certain responses in their parent cells. FFAR1 is a member of a small family of structurally and functionally related GPRs termed free fatty acid receptors (FFARs). This family includes at least three other FFARs viz., FFAR2, FFAR3, and FFAR4. FFARs bind and thereby are activated by certain fatty acids.
Free fatty acid receptor 2 (FFAR2), also termed G-protein coupled receptor 43 (GPR43), is a rhodopsin-like G-protein coupled receptor. It is coded by the FFAR2 gene. In humans, the FFAR2 gene is located on the long arm of chromosome 19 at position 13.12. Like other GPCRs, FFAR2s reside on the surface membrane of cells and when bond to one of their activating ligands regulate the function of their parent cells. FFAR2 is a member of a small family of structurally and functionally related GPRs termed free fatty acid receptors (FFARs). This family includes three other receptors which, like FFAR2, are activated by certain fatty acids: FFAR1, FFAR3 (GPR41), and FFAR4 (GPR120). FFAR2 and FFAR3 are activated by short-chain fatty acids whereas FFAR1 and FFAR4 are activated by long-chain fatty acids.
Islet cell autoantigen 1 is a protein that in humans is encoded by the ICA1 gene.
Receptor-type tyrosine-protein phosphatase N2 (R-PTP-N2) also known as islet cell autoantigen-related protein (ICAAR) and phogrin is an enzyme that in humans is encoded by the PTPRN2 gene. PTPRN and PTPRN2 are both found to be major autoantigens associated with insulin-dependent diabetes mellitus.
A NOG (NOD/Shi-scid/IL-2Rγnull) mouse is a new generation of severely immunodeficient mouse, developed by Central Institute for Experimental Animals (CIEA) in 2000. The NOG mouse accepts heterologous cells much more easily compared with any other type of immunodeficient rodent models, such as nude mouse and NOD/scid mouse. Thus, the mouse can be the best model as a highly efficient recipient of human cells to engraft, proliferate and differentiate. This unique feature offers a great opportunity for enhancing therapy researches of cancer, leukemia, visceral diseases, AIDS, and other human diseases. It also provides applications for cancer, infection, regeneration, and hematology researches.
Chemerin, also known as retinoic acid receptor responder protein 2 (RARRES2), tazarotene-induced gene 2 protein (TIG2), or RAR-responsive protein TIG2 is a protein that in humans is encoded by the RARRES2 gene.
The NSG mouse is a brand of immunodeficient laboratory mice, developed and marketed by Jackson Laboratory, which carries the strain NOD.Cg-Prkdcscid Il2rgtm1Wjl/SzJ. NSG branded mice are among the most immunodeficient described to date. NSG branded mice lack mature T cells, B cells, and natural killer (NK) cells. NSG branded mice are also deficient in multiple cytokine signaling pathways, and they have many defects in innate immunity. The compound immunodeficiencies in NSG branded mice permit the engraftment of a wide range of primary human cells, and enable sophisticated modeling of many areas of human biology and disease. NSG branded mice were developed in the laboratory of Dr. Leonard Shultz at Jackson Laboratory, which owns the NSG trade mark.
TOL101, is a murine-monoclonal antibody specific for the human αβ T cell receptor. In 2010 it was an Investigational New Drug under development by Tolera Therapeutics, Inc.
Freund's adjuvant is a solution of antigen emulsified in mineral oil and used as an immunopotentiator (booster). The complete form, Freund's Complete Adjuvant is composed of inactivated and dried mycobacteria, whereas the incomplete form lacks the mycobacterial components. It is named after Jules T. Freund.
Islet resident macrophages are the predominant myeloid cell of the pancreatic islets of langerhans.