Interleukin-10 blocks in vitro replication of human cytomegalovirus by inhibiting the virus-induced autophagy in MRC5 cells

• We examined the change of IL-10 receptor expression in MRC-5 cells under different conditions.
• IL-10 inhibits autophagy in MRC-5 cells induced by HCMV infection.
• HCMV replications are repressed when autophagy is inhibited by IL-10 treatment.

BackgroundInterleukin-10 is an important cytokine that regulates immune response. Previous studies have shown that human cytomegalovirus can trigger cell autophagy during the early stages of infection. To our knowledge, whether IL-10 inhibits HCMV-induced autophagy and virus replication has not been studied previously.ObjectivesWe investigated whether IL-10 affects cell viability and autophagy under the conditions of starvation and HCMV infection by using the MRC5 cell line. We also explored the role of IL-10-mediated autophagy on HCMV replication.ResultsOur data showed that IL-10 inhibited the autophagic flux of the MRC5 cells irrespective of starvation or HCMV infection, and suppressed HCMV replication. The promotion of autophagy with either a pharmacological inducer (rapamycin), or a technique to over-express the BECN1 gene reversed the effect of IL-10 on virus replication. Furthermore, the PI3K/Akt signal pathway was activated when the cells were pretreated with IL-10.ConclusionsOur results indicated that IL-10 can suppress HCMV replication by inhibiting autophagy in host cells during the early stages of infection.