For the Mouse gene set with the same name, see BIOCARTA_CTLA4_PATHWAY

Systematic name M1467
Brief description The Co-Stimulatory Signal During T-cell Activation
Full description or abstract For a T cell to be activated by a specific antigen, the T cell receptor must recognize complexes of MHCI with the antigen on the surface of an antigen-presenting cell. T cells and the T cell receptor complex do not respond to antigen in solution, but even for the specific antigen they only respond to antigen-MHC-1 complexes on the cell surface. This interaction is necessary for T cell activation, but it is not sufficient. T cell activation also requires a co-stimulatory signal involving interaction of CD28 on the T cell with CD80 or CD86 (B7 family genes) on the antigen-presenting cell. CD28 activates a signal transduction pathway acting through PI-3K, Lck and Grb-2/ITK to provide its co-stimulatory signal for T cell activation. Another means to control T cell activation is by expressing factors that down-regulate T cell activation. Signaling by activated T cell receptors induces expression of CTLA-4, a receptor that opposes T cell activation. CTLA-4 has a higher affinity than CD28 for B7 proteins, terminating T cell activation. ICOS is a protein related to CD28 that is only expressed on activated T cells, and that provides another important co-stimulatory signal. The requirement for co-stimulatory signals provides additional control mechanisms that prevent inappropriate and hazardous T cell activation.
Collection C2: Curated
      CP: Canonical Pathways
            CP:BIOCARTA: BioCarta Pathways
Source publication  
Exact source  
Related gene sets  
External links
Filtered by similarity ?
Source species Homo sapiens
Contributed by BioCarta
Source platform or
identifier namespace
Dataset references  
Download gene set format: grp | gmt | xml | json | TSV metadata
Compute overlaps ? (show collections to investigate for overlap with this gene set)
Compendia expression profiles ? NG-CHM interactive heatmaps
(Please note that clustering takes a few seconds)
GTEx compendium
Human tissue compendium (Novartis)
Global Cancer Map (Broad Institute)
NCI-60 cell lines (National Cancer Institute)

Legacy heatmaps (PNG)
GTEx compendium
Human tissue compendium (Novartis)
Global Cancer Map (Broad Institute)
NCI-60 cell lines (National Cancer Institute)
Advanced query Further investigate these 22 genes
Gene families ? Categorize these 22 genes by gene family
Show members (show 42 source identifiers mapped to 22 genes)
Version history 7.0: Changed members. Upgraded to final version of Biocarta.

See MSigDB license terms here. Please note that certain gene sets have special access terms.