Insulin B (15-23)

Product Name: Insulin B (15-23)

Sequence One Letter Code: LYLVCGERG

Sequence Three Letter Code: H-Leu-Tyr-Leu-Val-Cys-Gly-Glu-Arg-Gly-OH

Chemical Formula:C44H72N12O13S1

Molecular Weight: 1009.3

Purity: 95%

Form: Lyophilized

Storage Conditions: - 20 °C

Research Area: Diabetes and Metabolic Syndrome

Source / Species: pig, bovine

Conjugation: Unconjugated

Code Nacres: NA.26

Application: This peptide corresponds to amino acids 15–23 of the human insulin B chain and represents an immunodominant epitope recognized by islet-associated T cells in autoimmune diabetes. It is commonly used in immunological studies to evaluate antigen-specific T-cell responses directed against pancreatic β-cell antigens. The peptide can stimulate diabetogenic CD4⁺ and CD8⁺ T lymphocytes, allowing researchers to measure cytokine production such as interferon-γ (IFN-γ) and interleukin-17 (IL-17) in functional immune assays. Because insulin-derived epitopes play a central role in autoimmune recognition of pancreatic islets, this peptide is widely used to investigate mechanisms underlying type 1 diabetes pathogenesis. It supports research on antigen presentation, T-cell activation, and immune tolerance, and is particularly useful in experimental models that examine pancreatic islet inflammation, cytotoxic T-cell responses, and autoimmune destruction of insulin-producing β cells.

Current Research: Type 1 diabetes (T1D) is an autoimmune disease characterized by immune-mediated destruction of pancreatic β cells, the insulin-producing cells responsible for maintaining glucose homeostasis. In this condition, autoreactive T lymphocytes recognize specific protein fragments derived from β-cell antigens and initiate inflammatory responses that progressively impair insulin production. Among the most extensively studied autoantigens in T1D is insulin itself, particularly epitopes derived from the insulin B chain. The insulin B chain (15–23) peptide represents a well-characterized immunodominant epitope that is recognized by islet-associated T cells and widely used as a model antigen in studies of autoimmune diabetes. Insulin as an Autoantigen in Type 1 Diabetes In healthy individuals, immune tolerance mechanisms prevent T cells from reacting against self-proteins such as insulin. However, in type 1 diabetes these tolerance mechanisms can fail, allowing autoreactive T cells to recognize β-cell antigens. Insulin is considered a primary autoantigen in the disease because it is uniquely produced by pancreatic β cells and frequently targeted by immune responses early in disease development. Fragments of the insulin molecule can be processed by antigen-presenting cells (APCs) and displayed on major histocompatibility complex (MHC) molecules. When autoreactive T cells encounter these peptide–MHC complexes, they become activated and initiate immune responses directed against pancreatic islets. One of the most important epitopes involved in this process is the B chain (15–23) region of insulin, which is strongly recognized by T cells in experimental models of autoimmune diabetes. Immunodominant Epitope Recognition The insulin B chain (15–23) peptide contains a sequence that can be presented by specific MHC class I or class II molecules, depending on the experimental system. Once presented on the surface of antigen-presenting cells, this epitope can be recognized by autoreactive CD4⁺ and CD8⁺ T cells. Because of its strong immunogenicity in autoimmune settings, this peptide is considered an immunodominant epitope—meaning it frequently triggers T-cell responses during autoimmune recognition of pancreatic β cells. Activation of these T cells contributes to the inflammatory cascade that ultimately results in β-cell destruction and loss of insulin production, a defining feature of type 1 diabetes. Studying Antigen-Specific T-Cell Responses Synthetic versions of the insulin B chain (15–23) peptide are widely used in laboratory studies to examine antigen-specific T-cell responses. By stimulating immune cells with the peptide in vitro, researchers can evaluate how T cells recognize β-cell antigens and how these responses contribute to disease progression. These experiments often involve culturing T cells with antigen-presenting cells loaded with the peptide and measuring functional responses such as T-cell proliferation or cytokine secretion. The peptide therefore serves as a controlled stimulus that allows researchers to analyze immune reactivity toward insulin-derived antigens. Measuring Cytokine Production in Functional Assays Activated T cells responding to insulin epitopes produce a range of pro-inflammatory cytokines that contribute to autoimmune pathology. Two commonly measured cytokines in these studies are interferon-γ (IFN-γ) and interleukin-17 (IL-17). IFN-γ is typically associated with Th1-type immune responses, which promote inflammatory processes and activation of immune effector cells. IL-17 is produced by Th17 cells and contributes to inflammatory signaling and recruitment of additional immune cells to sites of tissue damage. By measuring cytokine production following stimulation with the insulin B chain peptide, researchers can assess the strength and nature of antigen-specific immune responses. Such assays help reveal how immune cells contribute to the inflammatory environment within pancreatic islets. Applications in Experimental Models of Autoimmune Diabetes The insulin B chain (15–23) peptide is especially important in experimental models of type 1 diabetes, such as the non-obese diabetic (NOD) mouse model. In these systems, autoreactive T cells specific for insulin epitopes play a major role in initiating islet inflammation. Researchers use the peptide to examine several aspects of autoimmune disease development, including: Antigen presentation by dendritic cells and other APCs Activation and expansion of diabetogenic T cells Cytotoxic responses against pancreatic β cells Inflammatory signaling within pancreatic islets These studies help clarify how immune responses against insulin contribute to the progression of autoimmune diabetes. Investigating Immune Tolerance Mechanisms Beyond studying disease mechanisms, the insulin B chain (15–23) peptide is also used in research exploring immune tolerance strategies. Because this epitope is central to autoimmune recognition of β cells, it provides a useful model for investigating approaches that aim to restore immune tolerance and prevent T-cell–mediated tissue damage. Experimental therapies designed to induce antigen-specific tolerance often rely on defined peptides such as this one to selectively modulate immune responses toward β-cell antigens. A Key Tool for Autoimmune Diabetes Research The insulin B chain (15–23) peptide has become a widely used reagent in immunology research focused on type 1 diabetes. By representing a key autoantigenic epitope recognized by islet-associated T cells, it enables controlled investigation of antigen presentation, T-cell activation, and inflammatory cytokine responses. Through its application in functional immune assays and experimental disease models, this peptide continues to support studies aimed at understanding autoimmune mechanisms, pancreatic islet inflammation, and immune tolerance in type 1 diabetes.