InVivo Anti-mouse/human/rat/mo

可诱导共刺激因子（inducible co-stimulator, ICOS）又名CD278，于1999年被鉴定出来，是B7家族中B7-H2（CD275）分子的受体，B7-H2与ICOS结合，介导T细胞的共刺激信号，从而引起T细胞的增生和IL-4、IL-8等白介素的产生，参与T细胞（T_reg）的负性调节活动，辅助B细胞的免疫反应。配体&作用机制：ICOSL（ICOS配体），在抗原呈递细胞（如树突状细胞、B细胞和巨噬细胞）及部分非免疫细胞上表达。ICOSL与ICOS结合后，激活PI3K/AKT信号通路，促进细胞因子（如IL-4、IL-10）分泌，增强T细胞效应。表达位置：主要表达在活化后的T细胞（包括CD4⁺和CD8⁺ T细胞）上

The promotion of antitumor response by targeting co-stimulatory B7 superfamily members has become evident to create a new wave of cancer immunotherapy. Inducible Co-Stimulator (ICOS), which is expressed on activated T cells, gained interest in the translational medicine community.Areas covered: We performed an extensive literature review using the keywords 'ICOS' and 'cancer', and the Clinicaltrials.gov database for early phase clinical trials targeting ICOS. In this review, we highlight the dual role of ICOS in oncogenesis in different malignancies. We summarize the current state of knowledge about ICOS/ICOSL pathway targeting by immunotherapies.Expert opinion: Due to its multifaceted link with anti-tumor immunity, both antagonist and agonist antibodies might be of interest to target the ICOS/ICOSL pathway for tumor treatment. Indeed, ICOS activation might potentiate the effect of an inhibitory checkpoint blockade, while its neutralization could decrease the function of immunosuppressive Tregs and inhibit lymphoid tumor cells expressing Tfh markers.

The C398.4A monoclonal antibody reacts with mouse, human, rat and monkey ICOS (inducible T cell co-stimulator), also known as CD278. ICOS is a 47-57 kDa homodimeric glycoprotein belonging to the CD28 family of costimulatory molecules. ICOS is expressed on activated T cells and upon ICOSL binding, co-stimulates T and B cell responses. The ligand Is expressed on antigen presenting cells including splenic B cells, dendritic cells, and macrophages. ICOS signaling is also thought to be important for maintaining regulatory T cell homeostasis. The C398.4A antibody is commonly used to costimulate T cell activation and proliferation in vitro. C398.4A does not block the binding of ICOS to ICOSL.