TRIM28 regulates the coagulation cascade inhibited by p72 of African swine fever virus

Abstract

In 2018, African swine fever virus (ASFV) emerged in China, causing extremely serious economic losses to the domestic pig industry. Infection with ASFV can cause disseminated coagulation, leading to the consumption of platelets and coagulation factors and severe bleeding. However, the mechanism of virus-induced coagulation has yet to be established. In our study, ASFV downregulated the coagulation process, as detected by D-dimer (D2D) and Factor X (F10) expression in pigs challenged with ASFV HLJ/18. In vitro, ASFV infection increased Factor IX (F9) and Factor XII (F12) expression while downregulating F10 expression in porcine alveolar macrophages (PAMs). African swine fever virus induced both intrinsic and extrinsic coagulation cascades. In addition, several encoded proteins have been proven to affect the expression of the crucial coagulation protein F10, and among the encoded proteins, p72 inhibits the activity and expression of F10. Proteomicanalysis also revealedthat p72 isinvolved in the coagulation cascade. p72 can interact with F10, and its inhibitory functional domains include amino acids 423-432 and amino acids 443−452. Finally, we found that F10 and p72 interact with tripartite motif-containing protein 28 (TRIM28). TRIM28 knockdown resulted in a decrease in F10 expression. Importantly, TRIM28 contributes to the reduction in F10 protein expression regulated by p72. Our findings revealed an inhibitory effect of the viral protein p72 on the ASFV infection-induced coagulation cascade and a role of TRIM28 in reducing F10 expression, revealing a molecular mechanism of ASFV-associated coagulation.