rhBTN3A2, CF (50 UG)

Background: BTN3A2

BTN3A2 (Butyrophilin subfamily 3 member A2; also BTF3 and BT3.2) is a 36 kDa (predicted) glycoprotein, member of the BTN family, Ig Superfamily of molecules. It is postulated to be expressed on immune-related cells, as it has a structural similarity to MHC and CD80/CD86 molecules. Mature human BTN3A2 is a 305 amino acid (aa) type I transmembrane protein. 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. A rodent counterpart to BTN3A2 has not been reported. BTN3A2 mRNA over‑expression was associated with a good prognosis in relation to disease-free and overall survival in a cohort of 55 epithelial ovarian cancer (EOC) patients (1). Another study in a larger cohort of 199 high-grade EOC patients further confirmed that the protein expression of BTN3A2 in ovarian cancer tissues is positively correlated with the intraepithelial infiltration of CD4⁺ and CD8⁺ T cells (2), suggesting that BTN3A2 was a co-stimulatory molecule to modulate the infiltration of immune cells and thus the anti-cancer immunity. In consistent with previous publications, our in-house studies on BTN3A2 showed that BTN3A2 co-stimulated anti‑CD3 induced IFN-gamma secretion on CD3⁺ cells.