The interleukin superfamily is a vital group of cytokine proteins involved in regulating immune and inflammatory responses. It includes multiple cytokine molecules that transmit signals between immune and non-immune cells by binding to specific receptors, thereby influencing cell proliferation, differentiation, activation, and function.
Members of the interleukin superfamily are typically named with the prefix IL, such as IL-1, IL-2, IL-6, and so on. Each member has distinct biological functions, signaling pathways, and specific receptor molecules. They play roles in various aspects of the immune system, ranging from the activation and proliferation of immune cells to the regulation of immune responses and inflammation.
The interleukin superfamily significantly contributes to immune regulation. Some members, like IL-1 and IL-6, have pro-inflammatory effects, regulating and coordinating inflammatory and immune responses, as well as promoting immune cell activation and the release of inflammatory mediators. Other members, such as IL-10, have anti-inflammatory effects, suppressing the inflammatory response, reducing tissue damage, and mitigating immune hyperresponsiveness.
Moreover, the interleukin superfamily is involved in the development and differentiation of immune cells. For example, IL-2 plays a crucial role in T cell proliferation and activation, IL-4 promotes B cell differentiation into antibody-producing cells, and IL-7 is essential for lymphocyte development.
Studying the interleukin superfamily holds great significance in understanding immune system regulation, disease occurrence and progression, and the development of therapeutic strategies. Many autoimmune diseases, infectious diseases, and tumors are associated with abnormal expression and dysfunction of interleukin superfamily members. Consequently, therapeutic approaches targeting specific interleukins, such as the development of IL-specific antibodies and inhibitors, have become important research directions, offering new hopes and opportunities for treating related diseases.
IL-2 is a key cytokine involved in T cell proliferation and differentiation. It plays a central role in the regulation of immune responses, especially in the activation of cytotoxic T cells and natural killer (NK) cells. IL-2 is also used in the treatment of certain cancers and autoimmune diseases.
IL-4 is mainly produced by activated T cells and mast cells. It plays a crucial role in the differentiation of naive CD4+ T cells into Th2 cells involved in humoral immune responses. IL-4 promotes B cell proliferation, antibody class shift to IgE, and development of allergic reactions.
IL-5 is mainly produced by Th2 cells and mast cells. It plays a central role in the development, activation and survival of eosinophils. IL-5 is involved in allergic inflammation, especially in diseases such as asthma and eosinophilic disease.
IL-13 is mainly produced by Th2 cells and is involved in allergic inflammation and tissue remodeling. It has some overlapping functions with IL-4 and contributes to the development of asthma, allergic rhinitis and other allergic diseases.
IL-14 is a cytokine that belongs to one of the members of the interleukin family. IL-14 is mainly produced by activated B cells, but can also be produced by other immune cells such as macrophages and T cells. It plays an important role in immune regulation and B cell function.
IL-32 is a cytokine that was originally described as a natural killer cell stimulator (NK4). IL-32 is a polypeptide molecule that exists in multiple subtypes in the human body, including IL-32α, IL-32β, IL-32γ, IL-32δ and IL-32ε. IL-32 is primarily produced by a variety of cell types, including leukocytes, epithelial cells, endothelial cells, and tumor cells.
IL-34 is a cytokine that was first discovered in 2008. It is a protein molecule produced by tissues such as the bone marrow and spleen. IL-34 shares certain structural and functional similarities with other cytokine family members, such as macrophage colony-stimulating factor (CSF-1) and interleukin-33 (IL-33).