Antigen
In immunology, antigens (Ag) are structures (aka substances) specifically bound by antibodies (Ab) or a cell surface version of Ab ~ B cell antigen receptor (BCR). The term antigen originally described a structural molecule that binds specifically to an antibody only in the form of native antigen. It was expanded later to refer to any molecule or a linear molecular fragment after processing the native antigen that can be recognized by T-cell receptor (TCR). BCR and TCR are both highly variable antigen receptors diversified by somatic V(D)J recombination. Both T cells and B cells are cellular components of adaptive immunity. The Ag abbreviation stands for an antibody generator.
Adoptive cell transfer
Cancer-testis antigens are a family of intracellular proteins that are expressed during fetal development, but with little expression in normal adult tissues. More than 100 such molecules are epigenetically up-regulated in from 10 to 80% of cancer types. However, they lack high levels of protein expression. Approximately 10% of common cancers appear to express enough protein to be of interest for antitumor T cells. Low levels of some cancer-testes antigens are expressed in normal tissues, with associated toxicities. The NYESO-1 cancer-testes antigen has been targeted via a human TCR transduced into autologous cells. ORs were seen in 5 of 11 patients with metastatic melanoma and 4 of 6 patients with highly refractory synovial cell sarcoma.