Reovirus impairs T cell anti-tumor activity by minimizing MHC-I surface expression

In recent years, reovirus has been of major interest in cancer research. Its oncolytic properties enable reovirus to replicate inside and lyse tumor cells, while leaving healthy cells unharmed. This has led to the prospect of employing reovirus as an adjuvant drug in oncotherapy. Here we provided in-depth analysis of the effects of reovirus treatment on the T cell effector function towards the infected tumor cells. We illustrated that reovirus infection downregulates MHC-I complexes in reovirus-infected tumor cells. Moreover, we show that this downregulation significantly impairs the T-cell cytotoxicity response toward the infected tumor cells. Furthermore, we have revealed that reovirus infection impairs the processing of MHC-peptide complexes which leads to the observed MHC-I downregulation.Thus, Reovirus infection significantly impairs T-cell cytotoxcity toward the tumor cells. This could significantly alter the outcome of reovirus cancer therapy.