BamHI-A rightward reading frame 1 protein (BARF1) (BARF1)

BamHI-A rightward reading frame 1 (BARF1) is a secreted viral protein encoded by the Epstein-Barr virus (EBV) that functions as both a potent immunomodulator and an oncoprotein [UniProt: P03227]. It is primarily expressed during the lytic cycle of EBV infection and is characteristically found in EBV-associated epithelial malignancies, such as nasopharyngeal carcinoma (NPC) and EBV-associated gastric carcinoma (EBVaGC) [PubMed: 25406590]. BARF1 acts as a viral decoy receptor for colony-stimulating factor 1 (CSF1), effectively neutralizing it to inhibit the maturation and activation of macrophages, which facilitates viral immune evasion and creates a tumor-promoting microenvironment. Beyond its role in immune suppression, BARF1 directly contributes to oncogenesis by promoting cell cycle progression and inhibiting apoptosis through the up-regulation of the anti-apoptotic protein Bcl-2 [PubMed: 11099505]. Because BARF1 is specifically produced by EBV-infected tumor cells and secreted into the extracellular space, it represents a highly specific therapeutic target for monoclonal antibodies and a valuable diagnostic biomarker for EBV-related cancers.

Other names

Epstein-Barr virus BARF1EBV-BARF1vCSF-1RViral colony-stimulating factor 1 receptorBamHI-A fragment rightward reading frame 1

BARF1 acts as a soluble decoy receptor that binds to and neutralizes host colony-stimulating factor 1 (CSF1), thereby preventing its interaction with the cellular CSF1 receptor (CSF1R) and suppressing the differentiation and activation of monocytes and macrophages [PubMed: 12163498].