Anti-lipopolysaccharide factors(ALFs)exhibit a potent antimicrobial activity against a broad range of bacteria,filamentous fungi,and viruses.In previous reports,seven groups of ALFs(groups A–G)were identified in pena...Anti-lipopolysaccharide factors(ALFs)exhibit a potent antimicrobial activity against a broad range of bacteria,filamentous fungi,and viruses.In previous reports,seven groups of ALFs(groups A–G)were identified in penaeid shrimp.Among them,group D showed negative net charges and weak antimicrobial activity.Whether this group has antiviral function is not clear.In this study,the ALF sequences of penaeid shrimp were analyzed,and eight groups of ALF family(groups A–H)were identified.The four ALFs including MjALF-C2,MjALF-D1,MjALF-D2,and MjALF-E2 from kuruma shrimp Marsupenaeus japonicus were expressed recombinantly in Escherichia coli,and the antiviral activity was screened via injection of purified recombinant ALFs into shrimp following white spot syndrome virus(WSSV)infection.Results showed that the expression of Vp28(WSSV envelope protein)decreased significantly in the MjALF-D2-injected shrimp only.Therefore,MjALF-D2 was chosen for further study.Expression pattern analysis showed that MjAlf-D2 was upregulated in shrimp challenged by WSSV.The WSSV replication was detected in RNA,genomic DNA,and protein levels using VP28 and Ie1(immediate-early gene of WSSV)as indicators in MjALF-D2-injected shrimp following WSSV infection.Results showed that WSSV replication was significantly inhibited compared with that in the rTRX-or PBS-injected control groups.After knockdown of MjAlf-D2 in shrimp by RNA interference,the WSSV replication increased significantly in the shrimp.All these results suggested that MjALF-D2 has an antiviral function in shrimp immunity,and the recombinant ALF-D2 has a potential application for viral disease control in shrimp aquaculture.展开更多
A pair of primers was designed based on the vp28 gene and PCR was performed to amplify the gene from WSSV DNA. Inserting the DNA fragment to the yeast-E.coli shuffle vector pPICZ and the recombinant plasmid (pPICZVP28...A pair of primers was designed based on the vp28 gene and PCR was performed to amplify the gene from WSSV DNA. Inserting the DNA fragment to the yeast-E.coli shuffle vector pPICZ and the recombinant plasmid (pPICZVP28) that contains the target DNA fragment was obtained in the E.coli strain.The pPICZVP28 was introduced into Pichia pastoris strain X33 by electroporation. The transformant strain X33-1 was grown in BMGY media in fled flask at 28℃. Induced by methanol for 72h, the samples of cell pellets and supernatant were collected by centrifugation and analyzed by SDS-PAGE and Western-blot, which confirmed that the strain X33-1 can express the WSSV’s envelope protein vp28.展开更多
基金supported by grants from the National Natural Science Foundation of China(grant nos.31630084 and 31930112)the National Key Research and Development Program of China(grant no.2018YFD0900502).
文摘Anti-lipopolysaccharide factors(ALFs)exhibit a potent antimicrobial activity against a broad range of bacteria,filamentous fungi,and viruses.In previous reports,seven groups of ALFs(groups A–G)were identified in penaeid shrimp.Among them,group D showed negative net charges and weak antimicrobial activity.Whether this group has antiviral function is not clear.In this study,the ALF sequences of penaeid shrimp were analyzed,and eight groups of ALF family(groups A–H)were identified.The four ALFs including MjALF-C2,MjALF-D1,MjALF-D2,and MjALF-E2 from kuruma shrimp Marsupenaeus japonicus were expressed recombinantly in Escherichia coli,and the antiviral activity was screened via injection of purified recombinant ALFs into shrimp following white spot syndrome virus(WSSV)infection.Results showed that the expression of Vp28(WSSV envelope protein)decreased significantly in the MjALF-D2-injected shrimp only.Therefore,MjALF-D2 was chosen for further study.Expression pattern analysis showed that MjAlf-D2 was upregulated in shrimp challenged by WSSV.The WSSV replication was detected in RNA,genomic DNA,and protein levels using VP28 and Ie1(immediate-early gene of WSSV)as indicators in MjALF-D2-injected shrimp following WSSV infection.Results showed that WSSV replication was significantly inhibited compared with that in the rTRX-or PBS-injected control groups.After knockdown of MjAlf-D2 in shrimp by RNA interference,the WSSV replication increased significantly in the shrimp.All these results suggested that MjALF-D2 has an antiviral function in shrimp immunity,and the recombinant ALF-D2 has a potential application for viral disease control in shrimp aquaculture.
文摘A pair of primers was designed based on the vp28 gene and PCR was performed to amplify the gene from WSSV DNA. Inserting the DNA fragment to the yeast-E.coli shuffle vector pPICZ and the recombinant plasmid (pPICZVP28) that contains the target DNA fragment was obtained in the E.coli strain.The pPICZVP28 was introduced into Pichia pastoris strain X33 by electroporation. The transformant strain X33-1 was grown in BMGY media in fled flask at 28℃. Induced by methanol for 72h, the samples of cell pellets and supernatant were collected by centrifugation and analyzed by SDS-PAGE and Western-blot, which confirmed that the strain X33-1 can express the WSSV’s envelope protein vp28.
