Related Experiment Video
Updated: Jun 16, 2026

Use of Single Chain MHC Technology to Investigate Co-agonism in Human CD8+ T Cell Activation
Published on: February 28, 2019
Isoforms of human B7-H3 co-signalling molecule for T cell activation as potential immunoregulatory agents
B7 family molecules, which are expressed on antigen-presenting cells and display extracellular regions containing immunoglobulin (Ig) variable (V)- and constant (C)-like domains, are known to modulate T cell receptor (TCR)-mediated T cell activation by providing co-signals that are either stimulatory or inhibitory. One of the most recently identified members of this family is B7-H3 (B7 homologue 3). Here, evidence is presented that human B7-H3 exists as two isoforms: B7-H3 VC, which contains one IgV- and IgC-like domain, and B7-H3 VCVC, which contains two such domains. The latter represents the predominant B7-H3 molecule detectable in various human tissues. Both B7-H3 isoforms are shown to decrease the proliferation and cytokine production induced by TCR activation of human T cells in vitro. It is therefore claimed that B7-H3 molecules may provide tools to modulate immune responses for therapeutic purpose.
B7 family molecules, which are expressed on antigen-presenting cells and display extracellular regions containing immunoglobulin (Ig) variable (V)- and constant (C)-like domains, are known to modulate T cell receptor (TCR)-mediated T cell activation by providing co-signals that are either stimulatory or inhibitory. One of the most recently identified members of this family is B7-H3 (B7 homologue 3). Here, evidence is presented that human B7-H3 exists as two isoforms: B7-H3 VC, which contains one IgV- and IgC-like domain, and B7-H3 VCVC, which contains two such domains. The latter represents the predominant B7-H3 molecule detectable in various human tissues. Both B7-H3 isoforms are shown to decrease the proliferation and cytokine production induced by TCR activation of human T cells in vitro. It is therefore claimed that B7-H3 molecules may provide tools to modulate immune responses for therapeutic purpose.
Related Concept Videos
B Cell Activation and Differentiation
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
T Cell Activation and Clonal Selection
Naive T cells that have not yet encountered an antigen express two primary CD...
T Cell Types and Functions
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
Receptor Downregulation in MVBs
The EGFR can initiate signaling pathways that lead to cell proliferation, migration, and differentiation. Overexpression of EGFR stimulates cells to proliferate. Excessive EGFR activation may...
TGF - β Signaling Pathway

