Immunology Antibodies

SPA4 is a surfactant protein-A (SP-A)-derived peptide which is an antagonist of toll-like receptor-4 (TLR4). SP-A and TLR4 have been identified as important pathogen-pattern recognition receptors (PPRRs). SP-A represents the majority of SPs and plays a key role in fighting pathogens and down-regulating inflammation, whereas TLR4 recognises pathogens and endogenous stress proteins and induces the inflammatory and adaptive immune responses.Over-activation of TLR4 induces inflammatory response via NF-KB and TNF-α cytokine. SPA4 has been shown to bind to TLR4 and inhibit the release of TNF-α in response to the most potent TLR4-ligand: Gram-negative bacteria-derived lipopolysaccharide (LPS), however SPA4 does not interfere with LPS binding to TLR4. The suppression of LPS-TLR4 signalling by SPA4 peptide alleviates inflammatory response.

A20FMDV2, a peptide derived from the foot and mouth disease virus, inhibits the epithelial-specific integrin alphavβ6 and here is labelled with 4-fluorobenzoyl as the light version of the PET ligand 4-[18F]Fluorobenzoyl A20FMDV2 which can be used for in vivo imaging.

Protease activated receptors (PARs) are a distinctive four-member family of seven transmembrane G protein-coupled receptors (GPCRs) widely expressed in inflammatory cells. PARs are cleaved by certain serine proteases to expose a tethered ligand domain, this ligand domain then binds to and activates the receptors to initiate multiple signalling cascades. These PAR-activating proteases therefore represent PAR agonists. This PAR-4 agonist peptide represents the N-terminal sequence of the 'tethered ligand' and is therefore capable of activating the receptor independently of N-terminal proteolysis.

Ara h 6 is one of the major allergenic proteins from peanut (Arachis hypogaea) which contains approximately 13 potential allergenic proteins. Ara h 6 is a member of the 2S albumins (conglutinins) belonging to the prolamin superfamily which also includes Ara h 2. 2S albumins contain major food allergens from seeds of many mono- and dicotyledon plants and share a common compact structure that renders the proteins highly resistant to proteolysis.Ara h 6 contains multiple disulphide-bridged cysteine residues, resulting in a tightly coiled, heat-stable, protease resistant core structure that may be important for allergenicity. In mouse models Ara h 2 and Ara h 6 are the main cause of effector responses such as mast cell degranulation and anaphylaxis.This peptide represents a tryptic peptide of Ara h 6. The phenylalanine residue at position 11 of this peptide is isotopically labelled with carbon-13 (9) and nitrogen-15 (1), giving this peptide a mass increase of 10 compared to the unlabelled peptide.

IL-33 is a member of the IL-1 superfamily of cytokines, a determination based in part on the molecules β-trefoil structure, a conserved structure type described in other IL-1 cytokines. IL-33 acts intracellularly as a nuclear factor and extracellularly as a cytokine.IL-33 has been associated with several disease states through Genome Wide Association Studies: asthma, allergy, endometriosis and hay fever. A single-nucleotide polymorphism rs928413 (A/G), is located in the 5' upstream region of IL33 gene, and its minor 'G' allele was identified as a susceptible variant for early childhood asthma and atopic asthma development.

Myelin oligodendrocyte glycoprotein (MOG) is a member of the immunoglobulin (Ig) protein superfamily and is expressed exclusively in the central nervous system (CNS) on the surface of myelin sheaths and oligodendrocyte processes. MOG is expressed at the onset of myelination, and therefore is a potential marker for oligodendrocyte maturation.MOG contains an extracellular domain, a transmembrane domain, a cytoplasmic loop, a membrane-associated region and a cytoplasmic tail.- MOG may function as a cell surface receptor or cell adhesion molecule. -Fifteen different alternatively spliced isoforms have been detected in humans. These are present either on the cell surface, the endoplasmic reticulum in the endocytic system, or in secreted form.The secreted form of MOG may trigger autoimmunity if released into the cerebrospinal fluid and periphery. MOG is thought to be a key target for autoantibodies and cell-mediated immune responses in inflammatory demyelinating diseases such as multiple sclerosis (MS) and is therefore widely studied in this field.Fragment 92-106 of MOG is able to induce experimental autoimmune/allergic encephalomyelitis (EAE), an animal model that resembles MS.

The MHC class II allele I-Ag7 is the allele associated with diabetes in the non-obese diabetic (NOD) mouse. I-Ag7 is also associated with spontaneous mouse models of arthritis and multiple sclerosis. The peptide mimotope mimics the structure of an epitope and therefore causes an antibody response similar to the one elicited by the epitope.

This peptide is derived from gliadin wheat protein residues 31-43. It elicits an innate immune response by upregulating expression of interleukin (IL)-15 and cyclooxygenase (COX)-2. This peptide also promotes expression of CD25 on monocytes and macrophages, expression of CD83 on dendritic cells, and p38 MAP kinase activation. Treatment with this peptide allows immunodominant epitopes (57-68 and 62-75) to induce T-cell activation and enterocyte apoptosis.

AF12198 is a selective receptor antagonist to the human cytokine, type 1 interleukin-1 (IL-1) and thus blocks IL-1β signalling. AF12198 can inhibit IL-1-induced IL-8 production by human dermal fibroblasts and IL-1-induced intercellular adhesion molecule-1 (ICAM-1) expression by endothelial cells. AF12198 also blocks IL-1 induction of IL-6 and down regulates IL-6 induction in monkeys. AF12198 does not bind the human type II IL-1 receptor, or the murine type I IL-1 receptor.IL-1 influences a wide range of immune and inflammatory responses. Sustained expression of even low levels of IL-1 can be harmful in chronic inflammatory diseases such as rheumatoid arthritis and inflammatory bowel disease.

Pro-opiomelanocortin (POMC)-derived peptides act on neurons expressing the Melanocortin 4 receptor (MC4R) to reduce body weight. Setmelanotide is a highly potent MC4R agonist that leads to weight loss in diet-induced obese animals and obese individuals with complete POMC deficiency.The endogenous ligand alpha-melanocyte-stimulating hormone (alpha-MSH) for MC4R has been shown to have a much lower affinity than Setmelanotide, explaining some of the drug's potency. Administration of Setmelanotide to wildtype mice resulted in significant weight loss while  MC4R knockout mice fail to respond. Setmelanotide is in numerous clinical trials and shows promising results. Patients with POMC defects upstream of MC4R show more significant responses to treatment than those with MC4R deficiency or obese controls.

The GHK tripeptide has many attributes which can positively impact human health. GHK can improve tissue repair, exhibit anti-cancer and anti-inflammatory properties, suppress age related molecules and restore chronic obstructive pulmonary disease fibroblasts.The GHK tripeptide is found in the human plasma and binds copper. It exerts its effects through its ability to up regulate and downregulate 4,000 human genes. Due to its ability to protect and regenerate aspects of human health, GHK-Cu can be used in products for skin and hair.Specifically during skin regeneration GHK-Cu can promote the synthesis of collagen and glycosa-minoglycans, increase the rate of wound healing and the formation of blood vessels.A palmitoyl group is present on the N-terminus.

BAM (8-22), the Bovine adrenal medulla 8-22 peptide is synthesised from proekephalin after it has undergone proteolytic cleavage. It can induce what is known as the 'itching' or 'scratching' response through activating, using an opioid independent mechanism, the G-protein coupled receptor MRGPRX1. This subsequently activates the Gαq/11 pathway and the cation channel TRPA1 histamine independent itch pathways.It is believed that BAM 8-22 can contribute to chronic itching in diseases such as cholestasis-related pruritus, in which patients are commonly diagnosed as having a reduction in bile flow.

PD-1 (24-38) peptide is derived from the programmed cell death-1 (PD-1) which interacts with its ligand, PD-L1 to regulate immune homeostasis. PD-1 and its ligand PD-L1 are critical in regulating T cell activation, tolerance and immuno-pathology. PD-1 is an immune checkpoint and guards against autoimmunity through two mechanisms. First, it promotes apoptosis of antigen-specific T-cells in lymph nodes. Second, it reduces apoptosis in regulatory T cells.Several types of cancer cells overexpress PD-L1 in order to escape from the PD-1/PD-L1 immuno-surveillance mechanism. Consequently PD-1 inhibitors and PD-L1 inhibitors could be used as a therapeutic in the treatment of cancers.

Peptide derived from gp100, a type 1 transmembrane glycoprotein and a homologue of the melanocyte specific protein Pme117. Gp100 may therefore constitute a useful target for specific immunotherapy against melanoma.

Ovalbumin (OVA) is the primary protein in egg-white, and is involved in initiating food allergies and asthma. It is a highly immunogenic protein and can be used for peptide conjugation in the development of antibodies.OVA (324-340) is a class I (Kb)-restricted peptide epitope of OVA. The ovalbumin fragment is presented by the class I MHC molecule, H-2Kb.

Ovalbumin (OVA) is the primary protein in egg-white, and is involved in initiating food allergies and asthma. It is a highly immunogenic protein and can be used for peptide conjugation in the development of antibodies.OVA (371-382) is a class I (Kb)-restricted peptide epitope of OVA. The ovalbumin fragment is presented by the class I MHC molecule, H-2Kb.