btf 4

The three butyrophilin BTN3A molecules, BTN3A1, BTN3A2, and BTN3A3, are members of the B7/butyrophilin-like group of Ig superfamily receptors, which modulate the function of T cells. BTN3A2 is overexpressed in gastric tumors, and deletion of BTN3A2 inhibited proliferation, migration, and invasion of gastric cancer cells. The butyrophilin 3 (BTN3) receptors are implicated in the T lymphocytes regulation and present a wide plasticity in mammals. A thorough phylogenetic analysis reveals a concerted evolution of BTN3 characterized by a strong and recurrent homogenization of the region encoding the signal peptide and the immunoglobulin variable (IgV) domain in Hominoids, where the sequences of BTN3A1 or BTN3A3 are replaced by BTN3A2 sequence.

Butyrophilin subfamily 3 member A2, also known as BT3.2, BTF3, BTF4 and BTN3A2, is a single-pass type I membrane protein. It is a member of the butyrophilin (BTN) family and the immunoglobulin (IG) superfamily. Mature human BTN3A2 is a 305 amino acid (aa) glycoprotein. It contains a 219 aa extracellular region with one V-type Ig-like domain, and a 65 aa cytoplasmic tail. The cytoplasmic region undergoes phosphorylation on two serines. There are three potential splice forms. BTN3A2 is postulated to be expressed on immune-related cells, as it has a structural similarity to MHC and CD80/CD86 molecules. It plays a role in T-cell responses in the adaptive immune response and inhibits the release of IFNG from activated T-cells.

BTN3A2/BT3.2 butyrophilin mRNA expression by tumoral cells was previously identified as a prognostic factor in a small cohort of high grade serous epithelial ovarian cancer (HG-EOC).In conclusion, BT3.2 protein is a potential prognostic biomarker for the identification of HG-EOC patients with better outcome. In contrast, high CD206 /CD68 expression is associated with high risk of disease progression.