TRAPPC4 (Trafficking Protein Particle Complex Subunit 4)

Research into the complex regulatory mechanisms of PD-L1 suggests that targeting DRG2, TRAPPC4, HIP1R, and CMTM6 could enhance the effectiveness of PD-1/PD-L1 blockade therapies. This strategy could create exciting new possibilities for cancer immunotherapy and improve patient outcomes.

TRAPPC4 was found as a key autoantigen in IRP, along with CD34+ cells as primary targets of autoantibody attacks. The identification of TRAPPC4 and its epitope provided insights into IRP pathogenesis and suggested potential diagnostic and therapeutic strategies.

Interestingly, the BRD4 inhibitor JQ-1, counteracted PD-L1 transcription and reduced its surface expression, suggesting that such a combination could improve the outcome of VPA treatment, also because it increased the cytotoxic effect of VPA. Also considering that this HDACi did not upregulate PD-L2 and that the supernatant of VPA-treated cancer cells did not increase PD-L1 expression on the surface of macrophages exposed to it.