Severe fever with thrombocytopenia syndrome(SFTS)is an emerging hemorrhagic fever disease caused by SFTSV,a newly discovered phlebovirus that is named after the disease.Currently,no effective vaccines or drugs are ava...Severe fever with thrombocytopenia syndrome(SFTS)is an emerging hemorrhagic fever disease caused by SFTSV,a newly discovered phlebovirus that is named after the disease.Currently,no effective vaccines or drugs are available for use against SFTSV infection,as our understanding of the viral pathogenesis is limited.Bortezomib(PS-341),a dipeptideboronic acid analog,is the first clinically approved proteasome inhibitor for use in humans.In this study,the antiviral efficacy of PS-341 against SFTSV infection was tested in human embryonic kidney HEK293T(293T)cells.We employed four different assays to analyze the antiviral ability of PS-341 and determined that PS-341 inhibited the proliferation of SFTSV in 293T cells under various treatment conditions.Although PS-341 did not affect the virus absorption,PS-341 treatment within a non-toxic concentration range resulted in a significant reduction of progeny viral titers in infected cells.Dual-luciferase reporter assays and Western blot analysis revealed that PS-341 could reverse the SFTSV-encoded nonstructural protein(NS)mediated degradation of retinoic acid-inducible gene-1(RIG-I),thereby antagonizing the inhibitory effect of NSs on interferons and blocking virus replication.In addition,we observed that inhibition of apoptosis promotes virus replication.These results indicate that targeting of cellular interferon pathways and apoptosis during acute infection might serve as the bases of future therapeutics for the treatment of SFTSV infections.展开更多
Severe fever with thrombocytopenia syndrome virus(SFTSV)is a highly pathogenic tick-borne bunyavirus that causes lethal infectious disease and severe fever with thrombocytopenia syndrome(SFTS)in humans.The molecular m...Severe fever with thrombocytopenia syndrome virus(SFTSV)is a highly pathogenic tick-borne bunyavirus that causes lethal infectious disease and severe fever with thrombocytopenia syndrome(SFTS)in humans.The molecular mechanisms and host cellular factors required for SFTSV infection remain uncharacterized.Using a genome-wide CRISPR-based screening strategy,we identified a host cellular protein,sorting nexin 11(SNX11)which is involved in the intracellular endosomal trafficking pathway,as an essential cell factor for SFTSV infection.An SNX11-KO HeLa cell line was established,and SFTSV replication was significantly reduced.The glycoproteins of SFTSV were detected and remained in later endosomal compartments but were not detectable in the endoplasmic reticulum(ER)or Golgi apparatus.pH values in the endosomal compartments of the SNX11-KO cells increased compared with the pH of normal HeLa cells,and lysosomal-associated membrane protein 1(LAMP1)expression was significantly elevated in the SNX11-KO cells.Overall,these results indicated that penetration of SFTSV from the endolysosomes into the cytoplasm of host cells was blocked in the cells lacking SNX11.Our study for the first time provides insight into the important role of the SNX11 as an essential host factor in the intracellular trafficking and penetrating process of SFTSV infection via potential regulation of viral protein sorting,membrane fusion,and other endocytic machinery.展开更多
基金supported by the National Science Foundation of China (31270201)the National Key Research and Development Program of China (2017YFA0205102)+1 种基金the Seed Foundation of Tianjin University (2014XRX-0026)the National Science Foundation of Tianjin (No.16JCQNJC09800)
文摘Severe fever with thrombocytopenia syndrome(SFTS)is an emerging hemorrhagic fever disease caused by SFTSV,a newly discovered phlebovirus that is named after the disease.Currently,no effective vaccines or drugs are available for use against SFTSV infection,as our understanding of the viral pathogenesis is limited.Bortezomib(PS-341),a dipeptideboronic acid analog,is the first clinically approved proteasome inhibitor for use in humans.In this study,the antiviral efficacy of PS-341 against SFTSV infection was tested in human embryonic kidney HEK293T(293T)cells.We employed four different assays to analyze the antiviral ability of PS-341 and determined that PS-341 inhibited the proliferation of SFTSV in 293T cells under various treatment conditions.Although PS-341 did not affect the virus absorption,PS-341 treatment within a non-toxic concentration range resulted in a significant reduction of progeny viral titers in infected cells.Dual-luciferase reporter assays and Western blot analysis revealed that PS-341 could reverse the SFTSV-encoded nonstructural protein(NS)mediated degradation of retinoic acid-inducible gene-1(RIG-I),thereby antagonizing the inhibitory effect of NSs on interferons and blocking virus replication.In addition,we observed that inhibition of apoptosis promotes virus replication.These results indicate that targeting of cellular interferon pathways and apoptosis during acute infection might serve as the bases of future therapeutics for the treatment of SFTSV infections.
基金supported by the National Key Project for Infectious Disease from the Ministry of Science and Technology (Grant No. 2018ZX10711-001)
文摘Severe fever with thrombocytopenia syndrome virus(SFTSV)is a highly pathogenic tick-borne bunyavirus that causes lethal infectious disease and severe fever with thrombocytopenia syndrome(SFTS)in humans.The molecular mechanisms and host cellular factors required for SFTSV infection remain uncharacterized.Using a genome-wide CRISPR-based screening strategy,we identified a host cellular protein,sorting nexin 11(SNX11)which is involved in the intracellular endosomal trafficking pathway,as an essential cell factor for SFTSV infection.An SNX11-KO HeLa cell line was established,and SFTSV replication was significantly reduced.The glycoproteins of SFTSV were detected and remained in later endosomal compartments but were not detectable in the endoplasmic reticulum(ER)or Golgi apparatus.pH values in the endosomal compartments of the SNX11-KO cells increased compared with the pH of normal HeLa cells,and lysosomal-associated membrane protein 1(LAMP1)expression was significantly elevated in the SNX11-KO cells.Overall,these results indicated that penetration of SFTSV from the endolysosomes into the cytoplasm of host cells was blocked in the cells lacking SNX11.Our study for the first time provides insight into the important role of the SNX11 as an essential host factor in the intracellular trafficking and penetrating process of SFTSV infection via potential regulation of viral protein sorting,membrane fusion,and other endocytic machinery.
