ICOS Human Recombinant Protein

ICOS: Enhances all basic T-cell responses to a foreign antigen, namely proliferation, secretion of lymphokines, up- regulation of molecules that mediate cell-cell interaction, and effective help for antibody secretion by B-cells. Essential both for efficient interaction between T and B-cells and for normal antibody responses to T-cell dependent antigens. Does not up- regulate the production of interleukin-2, but superinduces the synthesis of interleukin-10. Prevents the apoptosis of pre- activated T-cells. Plays a critical role in CD40-mediated class switching of immunoglobin isotypes. Defects in ICOS are the cause of immunodeficiency common variable type 1 (CVID1). CVID1 is a primary immunodeficiency characterized by antibody deficiency, hypogammaglobulinemia, recurrent bacterial infections and an inability to mount an antibody response to antigen. The defect results from a failure of B-cell differentiation and impaired secretion of immunoglobulins; the numbers of circulating B-cells is usually in the normal range, but can be lo. 2 isoforms of the human protein are produced by alternative splicing.

Protein type: Membrane protein, integral

Chromosomal Location of Human Ortholog: 2q33

Cellular Component: plasma membrane

Biological Process: T cell costimulation

Disease: Immunodeficiency, Common Variable, 1; Immunodeficiency, Common Variable, 2