Peptide antigens and controls
SB-PEPTIDE offers a wide range of solutions adapted to immunology research.
Peptide antigens catalog
Control peptide pools
Peptide pools are used as standards and controls to stimulate antigen-specific T-cells in functional T-cell assays. SB-PEPTIDE offers various control peptide pools including CEF control peptide pool, CMV pp65 peptide pool, Ovalbumin peptide pool.
SB-PEPTIDE can also prepare fully customized pools.
Epitope mapping service
SB-PEPTIDE offers non-conformational epitope mapping service. SB-PEPTIDE can synthesize the antigenic protein as a library of overlapped peptides (usually 15aa, 5aa overlap) and perform ELISA to determine the epitope.
Custom peptide synthesis service
- Standard peptide synthesis service: synthesis of individual and purified peptides
- Peptide library synthesis service: synthesis of hundreds of peptides in parallel
- Peptide conjugation to carrier proteins (KLH/BSA/OVA)
Depraetere, V. Origins of antigenic peptides. Nat Cell Biol 2, E75 (2000).
Peptides derived from cellular proteins are continuously exposed at the cell surface, in association with MHC class I molecules. Recognition of these MHC–peptide complexes by circulating lymphocytes is critical to the immune system’s tolerance of self-derived antigenic peptides, and to the onset of immune reactions against exogenous peptide antigens, such as viral antigens. Antigenic peptides were thought to be derived from the proteolytic degradation of a fraction of total cellular proteins. However, the results of two studies recently published in Nature (Reits et al. Nature 404, 774–778, 2000; Schubert et al. Nature 404, 770–774, 2000) indicate that the generation of antigenic peptides may instead depend upon continuous protein synthesis, the antigens themselves being created through the degradation of up to 30% of these newly synthesized proteins. Although apparently wasteful, this system would ensure rapid, efficient presentation of antigens to the immune system, regardless of the half lives of individual proteins.
Depraetere, V. Origins of antigenic peptides. Nat Cell Biol 2, E75 (2000). DOI: 10.1038/35010504
Pardoll DM, Nat Rev Cancer. 2012 Apr; 12(4): 252–264
Among the most promising approaches to activating therapeutic antitumour immunity is the blockade of immune checkpoints. Immune checkpoints refer to a plethora of inhibitory pathways hardwired into the immune system that are crucial for maintaining self-tolerance and modulating the duration and amplitude of physiological immune responses in peripheral tissues in order to minimize collateral tissue damage. It is now clear that tumours co-opt certain immune-checkpoint pathways as a major mechanism of immune resistance, particularly against T cells that are specific for tumour antigens. Because many of the immune checkpoints are initiated by ligand–receptor interactions, they can be readily blocked by antibodies or modulated by recombinant forms of ligands or receptors. Cytotoxic T-lymphocyte-associated antigen 4 (CTLA4) antibodies were the first of this class of immunotherapeutics to achieve US Food and Drug Administration (FDA) approval. Preliminary clinical findings with blockers of additional immune-checkpoint proteins, such as programmed cell death protein 1 (PD1), indicate broad and diverse opportunities to enhance antitumour immunity with the potential to produce durable clinical responses
Pardoll DM, Nat Rev Cancer. 2012 Apr; 12(4): 252–264. DOI: 10.1038/nrc3239
Antigen definition - Wikipedia
In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune response. The term antigen originally referred to a substance that is an antibody generator. Antigens can be proteins, peptides (amino acid chains), polysaccharides (chains of monosaccharides/simple sugars), lipids, nucleic acids, or other biomolecules or a solid particulate matter or a pollen grain.
Antigens are recognized by antigen receptors, including antibodies and T-cell receptors. Diverse antigen receptors are made by cells of the immune system so that each cell has a specificity for a single antigen. Upon exposure to an antigen, only the lymphocytes that recognize that antigen are activated and expanded, a process known as clonal selection. In most cases, an antibody can only react to and bind one specific antigen; in some instances, however, antibodies may cross-react and bind more than one antigen.
The antigen may originate from within the body (« self-protein ») or from the external environment (« non-self »). The immune system identifies and attacks « non-self » external antigens and usually does not react to self-protein due to negative selection of T cells in the thymus and B cells in the bone marrow.
Vaccines are examples of antigens in an immunogenic form, which are intentionally administered to a recipient to induce the memory function of the adaptive immune system towards antigens of the pathogen invading that recipient. The vaccine for seasonal influenza is a common example.