Antimicrobial peptides(AMPs)in insects are endogenous peptides that are effector components of the innate defense system of the insect.AMPs may serve as antimicrobial agents because of their small molecular weight and...Antimicrobial peptides(AMPs)in insects are endogenous peptides that are effector components of the innate defense system of the insect.AMPs may serve as antimicrobial agents because of their small molecular weight and broad-spectrum antimicrobial activity.In this study,we performed transcriptome analysis of cigarette beetle(Lasioderma serricorne)larvae,parasitized by the ectoparasitic wasp,Anisopteromalus calandrae.Several AMP genes were significantly upregulated following A.calandrae parasitism,postulating the hypothesis that the parasitization enhanced the host's resistance against pathogenic microorganisms through the regulation of host AMP genes.Specifically,3 AMP genes(LsDef1,LsDef2,and LsCole)were significantly upregulated and we studied their immune function in L.serricorne.Immune challenge and functional analysis showed that LsCole was responsible for the immune response against Gram-negative and Gram-positive bacteria,while LsDef1 and LsDef2 were involved in insect defense against Gram-positive bacteria.Purified recombinant LsCole exhibited antimicrobial activities against the Gram-negative bacterium Escherichia coli and the Gram-positive bacterium Staphylococcus aureus.LsDef2 showed an antibacterial effect against S.aureus.LsCole and LsDef2 exhibited antibiofilm activity against S.aureus.The 2 AMPs disrupted cell membranes and caused leakage of S.aureus cell contents.The results indicated that the 3 AMPs in L.serricorne are involved in the innate immunity of this pest insect.These AMPs may have potential as antimicrobial agents for bacterial infection chemotherapy.Hence,data are discussed in relation to new control strategies with greater biosafety against pest insects with use of microbial biocontrol agents in combination with RNA interference against the insect's defensive AMP genes.展开更多
The IκB kinases IKKα and IKKβ and the IKK-related kinases TANK-binding kinase 1 （TBK1） and IKKε are the master regulators of the NF-κB signaling pathway. Although this pathway has been extensively studied in ma...The IκB kinases IKKα and IKKβ and the IKK-related kinases TANK-binding kinase 1 （TBK1） and IKKε are the master regulators of the NF-κB signaling pathway. Although this pathway has been extensively studied in mammals, less attention has been paid in crustaceans, which have significant economic value. Here, we report the cloning and functional studies of two IKK homologs, LvlKKβ and LvlKKε, from Pacific white shrimp, Litopenaeus vannamei. LvlKKβ and LvlKKα mRNAs are widely expressed in different tissues and are responsive to white spot syndrome virus （WSSV） infection. When overexpressed in Drosophila S2 cells, LvlKKβ but not LvlKKε activates the promoters of NF-κB pathway-controlled antimicrobial peptide genes （AMPs）, such as the Penaeidins （PENs）. In HEK 293T cells, both LvlKKβ and LvlKKε activate an NF-κB reporter. The silencing of LvlKKβ or LvlKKε using double-stranded RNA （dsRNA）-mediated RNA interference （RNAi） decreases the expression of L. vannamei AMPs, including PENs, lysozyme and crustins. Intriguingly, LvlKKβ- or LvlKKε-silenced L. vannameiare resistant to WSSV infection. We hypothesized that successful infection with WSSV requires the activation of the IKK-NF-κB signaling pathway to modulate viral gene expression. We constructed luciferase reporters for 147 WSSV genes. By screening, we found that the WSSV051, WSSV059, WSSV069, WSSV083, WSSV090, WSSV107, WSSV244, WSSV303, WSSV371 and WSSV445 promoters can be activated by LvlKKβ or LvlKKε in Drosophila S2 cells. Taken together, our results reveal that LvlKKβ and LvlKKε may participate in the regulation of shrimp AMPs and that WSSV may subvert the L. vannamei IKK-NF-κB signaling pathway to facilitate viral gene expression.展开更多
The innate immune system of insects is divided into humoral defenses that include the production of soluble effector molecules and cellular defenses like phagocytosis and encapsulation that are mediated by hemocytes. ...The innate immune system of insects is divided into humoral defenses that include the production of soluble effector molecules and cellular defenses like phagocytosis and encapsulation that are mediated by hemocytes. This review summarizes current understand- ing of the cellular immune response. Insects produce several terminally differentiated types of hemocytes that are distinguished by morphology, molecular and antigenic markers, and function. The differentiated hemocytes that circulate in larval or nymphal stage insects arise from two sources： progenitor cells produced during embryogenesis and mesodermally derived hematopoietic organs. Regulation of hematopoiesis and hemocyte differentiation also involves several different signaling pathways. Phagocytosis and encapsulation require that hemocytes first recognize a given target as foreign followed by activation of downstream signaling and effector responses. A number of humoral and cellular receptors have been identified that recognize different microbes and multicellular parasites. In turn, activation of these receptors stimulates a number of signaling pathways that regulate different hemocyte functions. Recent studies also identify hemocytes as important sources Of a number of humoral effector molecules required for killing different foreign invaders.展开更多
基金supported by the Program of Excellent Innovation Talents,Guizhou Province,China(Grant number 20206003-2)the Guizhou Province Graduate Research Fund YJSKYJJ[2021]053the Special Project for Science and Technology Development of Local(Guizhou)under the Guidance of the Central Government(QKZYD[2022]4013).
文摘Antimicrobial peptides(AMPs)in insects are endogenous peptides that are effector components of the innate defense system of the insect.AMPs may serve as antimicrobial agents because of their small molecular weight and broad-spectrum antimicrobial activity.In this study,we performed transcriptome analysis of cigarette beetle(Lasioderma serricorne)larvae,parasitized by the ectoparasitic wasp,Anisopteromalus calandrae.Several AMP genes were significantly upregulated following A.calandrae parasitism,postulating the hypothesis that the parasitization enhanced the host's resistance against pathogenic microorganisms through the regulation of host AMP genes.Specifically,3 AMP genes(LsDef1,LsDef2,and LsCole)were significantly upregulated and we studied their immune function in L.serricorne.Immune challenge and functional analysis showed that LsCole was responsible for the immune response against Gram-negative and Gram-positive bacteria,while LsDef1 and LsDef2 were involved in insect defense against Gram-positive bacteria.Purified recombinant LsCole exhibited antimicrobial activities against the Gram-negative bacterium Escherichia coli and the Gram-positive bacterium Staphylococcus aureus.LsDef2 showed an antibacterial effect against S.aureus.LsCole and LsDef2 exhibited antibiofilm activity against S.aureus.The 2 AMPs disrupted cell membranes and caused leakage of S.aureus cell contents.The results indicated that the 3 AMPs in L.serricorne are involved in the innate immunity of this pest insect.These AMPs may have potential as antimicrobial agents for bacterial infection chemotherapy.Hence,data are discussed in relation to new control strategies with greater biosafety against pest insects with use of microbial biocontrol agents in combination with RNA interference against the insect's defensive AMP genes.
文摘The IκB kinases IKKα and IKKβ and the IKK-related kinases TANK-binding kinase 1 （TBK1） and IKKε are the master regulators of the NF-κB signaling pathway. Although this pathway has been extensively studied in mammals, less attention has been paid in crustaceans, which have significant economic value. Here, we report the cloning and functional studies of two IKK homologs, LvlKKβ and LvlKKε, from Pacific white shrimp, Litopenaeus vannamei. LvlKKβ and LvlKKα mRNAs are widely expressed in different tissues and are responsive to white spot syndrome virus （WSSV） infection. When overexpressed in Drosophila S2 cells, LvlKKβ but not LvlKKε activates the promoters of NF-κB pathway-controlled antimicrobial peptide genes （AMPs）, such as the Penaeidins （PENs）. In HEK 293T cells, both LvlKKβ and LvlKKε activate an NF-κB reporter. The silencing of LvlKKβ or LvlKKε using double-stranded RNA （dsRNA）-mediated RNA interference （RNAi） decreases the expression of L. vannamei AMPs, including PENs, lysozyme and crustins. Intriguingly, LvlKKβ- or LvlKKε-silenced L. vannameiare resistant to WSSV infection. We hypothesized that successful infection with WSSV requires the activation of the IKK-NF-κB signaling pathway to modulate viral gene expression. We constructed luciferase reporters for 147 WSSV genes. By screening, we found that the WSSV051, WSSV059, WSSV069, WSSV083, WSSV090, WSSV107, WSSV244, WSSV303, WSSV371 and WSSV445 promoters can be activated by LvlKKβ or LvlKKε in Drosophila S2 cells. Taken together, our results reveal that LvlKKβ and LvlKKε may participate in the regulation of shrimp AMPs and that WSSV may subvert the L. vannamei IKK-NF-κB signaling pathway to facilitate viral gene expression.
文摘The innate immune system of insects is divided into humoral defenses that include the production of soluble effector molecules and cellular defenses like phagocytosis and encapsulation that are mediated by hemocytes. This review summarizes current understand- ing of the cellular immune response. Insects produce several terminally differentiated types of hemocytes that are distinguished by morphology, molecular and antigenic markers, and function. The differentiated hemocytes that circulate in larval or nymphal stage insects arise from two sources： progenitor cells produced during embryogenesis and mesodermally derived hematopoietic organs. Regulation of hematopoiesis and hemocyte differentiation also involves several different signaling pathways. Phagocytosis and encapsulation require that hemocytes first recognize a given target as foreign followed by activation of downstream signaling and effector responses. A number of humoral and cellular receptors have been identified that recognize different microbes and multicellular parasites. In turn, activation of these receptors stimulates a number of signaling pathways that regulate different hemocyte functions. Recent studies also identify hemocytes as important sources Of a number of humoral effector molecules required for killing different foreign invaders.
基金National Basic Research Program of China(Grant No.2005CB121000)Hi-Tech Research and Development Program of China(GrantNo.2006AA10A118)Fund for Foreign Scholars in University Research and Teaching Programs(Grant No.B07045)
