TIGIT (T cell immunoreceptor with Ig and ITIM domains), is a member of the immunoglobulin family of PVR (poliovirus receptor), and a type I transmembrane protein that includes the extracellular domain of IgV and immunoglobulin tyrosine tail-like phosphorylated fragments. TIGIT is mainly expressed on the surface of memory T cells, Tregs and NK cells. Similar to PD-1, TIM3, and LAG3, TIGIT is highly expressed in cancerous tissues and competitively binds to TIGIT receptors and DNAM-1 proteins on the surface of NK cells to reduce the NK cell killing efficiency. Therefore, anti-TIGIT antibody can enhance the function of DNAM-1 protein, further enhancing the ability of NK cells to destroy tumor cells.
mRNA expression verification:
Fig 1. Molecular identification of the B-hTIGIT humanized mice. Mouse TIGIT mRNA was detected in both the wild type and the B-hTIGIT heterozygous mice, while human TIGIT mRNA was detected only in the B-hTIGIT heterozygous mice.
Protein expression verification:
Fig 2. Spleen cells from both wild type (WT) C57BL/6 and the B-hTIGIT homozygous mice were analyzed by flow cytometry. Mouse TIGIT+ T cells were detected in the WT mice, while human TIGIT+ T cells were detected in the B-hTIGIT homozygous mice.