诱导协同刺激分子CD278重组兔单抗

ICOS

Inducible T-cell costimulator

Homodimer; disulfide-linked.

Isoform 1: Cell membrane; Single-pass type I membrane protein (Potential).Isoform 2: Secreted (Potential).

Activated T-cells. Highly expressed on tonsillar T-cells, which are closely associated with B-cells in the apical light zone of germinal centers, the site of terminal B-cell maturation. Expressed at lower levels in thymus, lung, lymph node and peripheral blood leukocytes. Expressed in the medulla of fetal and newborn thymus.

N-glycosylated.

Defects in ICOS are the cause of immunodeficiency common variable type 1 (CVID1) [MIM:607594]. 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.

Contains 1 Ig-like V-type (immunoglobulin-like) domain.

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 (By similarity).