Study Of The Function Of RIP3 In ISD Inducing Interferon-? Production

Receptor interacting protein 3(RIP3)is a key protein in necroptosis,which upon activation,could further activate downstream MLKL to execute cell death.Previous studies have shown that RIP3 can defend cells from viruses infection via initiaing necroptosis,now we try to explore whether RIP3 has non-necrotic antiviral functions.We found that in HEK293T cells,compared to STING overexpression alone,RIP3 and STING co-overexpression significantly enhances the activation of interferon-?(IFN-?)promoter.STING is a vital protein that mediates IFN-? production under cytoplasmic double stranded DNA(dsDNA)stimulation,we used the classical small dsDNA molecule ISD to activate the STING pathway and study the role of RIP3 in it.We found that overexpression of RIP3 in HeLa cells promotes cytoplasmic ISD-induced IFN-? production.Meanwhile,ISD-induced IFN-? production is significantly reduced in RIP3 knockdown or knockout HT-29 cells.Further studies showed that RIP3 could interact with STING and TBK1.RIP3 can promote phosphorylation of TBK1 and IRF3,thus,promote the expression of IFN-?,and this effect is dependent on its RHIM domain.Receptor interacting protein 1(RIP1)is another RHIM-containing protein,and we found that RIP1 and STING co-overexpression could also enhance the STING mediated activation of IFN-?promoter in HEK293T cells,while RIP 1-deficiency blocks the induction of IFN-?promoter by RIP3 and STING co-overexpression.Similarly,deletion of RIP1 in HT-29 cells attenuates the production of IFN-? induced by ISD.These datas suggest that RIP3 can affect the process of cytoplasmic ISD-induced IFN-? production,which gives us a new understanding of the role of RIP3 in protecting cells from pathogens invasion,particularly in the process of cytoplasmic dsDNA response,and provides new insights for treating related diseases.