The T helper cells (Th cells), also known as CD4+ cells or CD4-positive cells, are a type of T cell that play an important role in the adaptive immune system. They aid the activity of other immune cells by releasing cytokines. They are considered essential in B cell antibody class switching, breaking cross-tolerance in dendritic cells, in the activation and growth of cytotoxic T cells, and in maximizing bactericidal activity of phagocytes such as macrophages and neutrophils. CD4+ cells are mature Th cells that express the surface protein CD4. Genetic variation in regulatory elements expressed by CD4+ cells determines susceptibility to a broad class of autoimmune diseases.
CD32, also known as FcγRII or FCGR2, is a surface receptor glycoprotein belonging to the Ig gene superfamily. CD32 can be found on the surface of a variety of immune cells. CD32 has a low-affinity for the Fc region of IgG antibodies in monomeric form, but high affinity for IgG immune complexes. CD32 has two major functions: cellular response regulation, and the uptake of immune complexes. Cellular responses regulated by CD32 include phagocytosis, cytokine stimulation, and endocytic transport. Dysregulated CD32 is associated with different forms of autoimmunity, including systemic lupus erythematosus. In humans, there are three major CD32 subtypes: CD32A, CD32B, and CD32C. While CD32A and CD32C are involved in activating cellular responses, CD32B is inhibitory.
Cancer immunotherapy (immuno-oncotherapy) is the stimulation of the immune system to treat cancer, improving the immune system's natural ability to fight the disease. It is an application of the fundamental research of cancer immunology and a growing subspecialty of oncology.
Alloimmunity is an immune response to nonself antigens from members of the same species, which are called alloantigens or isoantigens. Two major types of alloantigens are blood group antigens and histocompatibility antigens. In alloimmunity, the body creates antibodies against the alloantigens, attacking transfused blood, allotransplanted tissue, and even the fetus in some cases. Alloimmune (isoimmune) response results in graft rejection, which is manifested as deterioration or complete loss of graft function. In contrast, autoimmunity is an immune response to the self's own antigens. Alloimmunization (isoimmunization) is the process of becoming alloimmune, that is, developing the relevant antibodies for the first time.
An antigen-presenting cell (APC) or accessory cell is a cell that displays antigen bound by major histocompatibility complex (MHC) proteins on its surface; this process is known as antigen presentation. T cells may recognize these complexes using their T cell receptors (TCRs). APCs process antigens and present them to T-cells.
Anakinra, sold under the brand name Kineret, is a biopharmaceutical medication used to treat rheumatoid arthritis, cryopyrin-associated periodic syndromes, familial Mediterranean fever, and Still's disease. It is a slightly modified recombinant version of the human interleukin 1 receptor antagonist protein. It is marketed by Swedish Orphan Biovitrum. Anakinra is administered by subcutaneous injection.
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.
B7 is a type of integral membrane protein found on activated antigen-presenting cells (APC) that, when paired with either a CD28 or CD152 (CTLA-4) surface protein on a T cell, can produce a costimulatory signal or a coinhibitory signal to enhance or decrease the activity of a MHC-TCR signal between the APC and the T cell, respectively. Binding of the B7 of APC to CTLA-4 of T-cells causes inhibition of the activity of T-cells.
Cluster of differentiation 40, CD40 is a type I transmembrane protein found on antigen-presenting cells and is required for their activation. The binding of CD154 (CD40L) on TH cells to CD40 activates antigen presenting cells and induces a variety of downstream effects.
Co-stimulation is a secondary signal which immune cells rely on to activate an immune response in the presence of an antigen-presenting cell. In the case of T cells, two stimuli are required to fully activate their immune response. During the activation of lymphocytes, co-stimulation is often crucial to the development of an effective immune response. Co-stimulation is required in addition to the antigen-specific signal from their antigen receptors.
CD28 is one of the proteins expressed on T cells that provide co-stimulatory signals required for T cell activation and survival. T cell stimulation through CD28 in addition to the T-cell receptor (TCR) can provide a potent signal for the production of various interleukins.
Belatacept, sold under the brand name Nulojix, is a fusion protein composed of the Fc fragment of a human IgG1 immunoglobulin linked to the extracellular domain of CTLA-4, which is a molecule crucial in the regulation of T cell costimulation, selectively blocking the process of T-cell activation. It is intended to provide extended graft and transplant survival while limiting the toxicity generated by standard immune suppressing regimens, such as calcineurin inhibitors. It differs from abatacept (Orencia) by only two amino acids.
The Cluster of differentiation 80 is a B7, type I membrane protein in the immunoglobulin superfamily, with an extracellular immunoglobulin constant-like domain and a variable-like domain required for receptor binding. It is closely related to CD86, another B7 protein (B7-2), and often works in tandem. Both CD80 and CD86 interact with costimulatory receptors CD28, CTLA-4 (CD152) and the p75 neurotrophin receptor.
Cluster of Differentiation 86 is a protein constitutively expressed on dendritic cells, Langerhans cells, macrophages, B-cells, and on other antigen-presenting cells. Along with CD80, CD86 provides costimulatory signals necessary for T cell activation and survival. Depending on the ligand bound, CD86 can signal for self-regulation and cell-cell association, or for attenuation of regulation and cell-cell disassociation.
Tremelimumab, sold under the brand name Imjudo, is a fully human monoclonal antibody used for the treatment of hepatocellular carcinoma. Tremelimumab is designed to attach to and block CTLA-4, a protein that controls the activity of T cells, which are part of the immune system.
ICOS ligand is a protein that in humans is encoded by the ICOSLG gene located at chromosome 21. ICOSLG has also been designated as CD275.
The following outline is provided as an overview of and topical guide to immunology:
Artificial antigen presenting cells (aAPCs) are engineered platforms for T-cell activation. aAPCs are used as a new technology and approach to cancer immunotherapy. Immunotherapy aims to utilize the body's own defense mechanism—the immune system—to recognize mutated cancer cells and to kill them the way the immune system would recognize and kill a virus or other micro-organisms causing infectious diseases. Antigen presenting cells are the sentinels of the immune system and patrol the body for pathogens. When they encounter foreign pathogens, the antigen presenting cells activate the T cells—“the soldiers of the immune system”— by delivering stimulatory signals that alert there is foreign material in the body with specific cell surface molecules (epitopes). aAPCs are synthetic versions of these sentinel cells and are made by attaching the specific T-cell stimulating signals to various macro and micro biocompatible surfaces like micron-sized beads. This can potentially reduce the cost while allowing control over generating large numbers of functional pathogen-specific T cells for therapy. Activated and stimulated T cells can be studied in this biomimetic contex and used for adoptive transfer as an immunotherapy.
An immune checkpoint regulator is a modulator of the immune system, that allows initiation of a productive immune response and prevents the onset of autoimmunity. Examples of such a molecule are cytotoxic T-lymphocyte antigen 4, which is an inhibitory receptor found on immune cells and programmed cell death 1 (CD279), which has an important role in down-regulating the immune system by preventing the activation of T-cells.
An antiarthritic is any drug used to relieve or prevent arthritic symptoms, such as joint pain or joint stiffness. Depending on the antiarthritic drug class, it is used for managing pain, reducing inflammation or acting as an immunosuppressant. These drugs are typically given orally, topically or through administration by injection. The choice of antiarthritic medication is often determined by the nature of arthritis, the severity of symptoms as well as other factors, such as the tolerability of side effects.
(what is this?) (verify) 