At least two types of insect immune responses require activation of plasma proteins by proteases in hemolymph. One is the proteolytic processing of cytokine precursors, including the Toll ligand Sp?tzle. A second protease-mediated response is the activation of phenoloxidase zymogens, which then oxidize circulating diphenols to quinones, precursors for deposition of melanin on the surface of invading organisms. Such Innate immune responses are likely to affect the outcome of infections of insect vectors with the pathogens and parasites they transmit. Responses modulated by proteases in blood are not simply linear pathways, but instead are often """"""""protease webs,"""""""" in which each protease may cleave multiple substrates, and active proteases may be regulated by several inhibitors. Previous work from our laboratory and others has established the lepidopteran insect, Manduca sexta, as a model system well suited for biochemical investigation of hemolymph proteases. The coming availability of a M. sexta genome sequence and new developments in proteomics technology make possible the investigation of serine protease webs in M. sexta hemolymph, using biochemical systems approaches. This research will be aimed at understanding hemolymph protease pathways, their potential cross-connections, and their regulation. The proteomics systems approach may reveal previously undiscovered protease-activated immune molecules of insects.
The specific aims of the project are to: 1. Use Manduca sexta genome and transcriptome sequence data to identify and annotate genes encoding putative serine proteases and protease inhibitors and to produce reagents for further experimentation. 2. Use a systems approach for proteomics experiments to identify pathway components and the substrate repertoire of selected hemolymph proteases, followed by experiments to validate and characterize interactions using purified proteins. 3. Investigate the regulation of protease pathways in hemolymph by serpins, using in vitro, ex vivo, and in vivo experimental approaches. The long term goals of the research are to gain a thorough understanding of the regulation of protease cascades that mediate innate immune responses in Manduca, to apply this knowledge to insect vectors of human diseases, and to apply advantages of the Manduca system for fundamental studies on the regulation of serine protease activity.
Innate immune responses are likely to affect the outcome of infections of insect vectors with the pathogens and parasites they transmit. The long term goals of the research are to gain a thorough understanding of the protease cascades that mediate innate immune responses in a model species, Manduca sexta, to apply this knowledge to insect vectors of human diseases, and to apply advantages of the M. sexta system for fundamental studies on the regulation of serine protease activity.
|Yang, Fan; Wang, Yang; Sumathipala, Niranji et al. (2018) Manduca sexta serpin-12 controls the prophenoloxidase activation system in larval hemolymph. Insect Biochem Mol Biol 99:27-36|
|Li, Miao; Christen, Jayne M; Dittmer, Neal T et al. (2018) The Manduca sexta serpinome: Analysis of serpin genes and proteins in the tobacco hornworm. Insect Biochem Mol Biol 102:21-30|
|Meekins, David A; Kanost, Michael R; Michel, Kristin (2017) Serpins in arthropod biology. Semin Cell Dev Biol 62:105-119|
|Brummett, Lisa M; Kanost, Michael R; Gorman, Maureen J (2017) The immune properties of Manduca sexta transferrin. Insect Biochem Mol Biol 81:1-9|
|Al Souhail, Qasim; Hiromasa, Yasuaki; Rahnamaeian, Mohammad et al. (2016) Characterization and regulation of expression of an antifungal peptide from hemolymph of an insect, Manduca sexta. Dev Comp Immunol 61:258-68|
|Kanost, Michael R; Arrese, Estela L; Cao, Xiaolong et al. (2016) Multifaceted biological insights from a draft genome sequence of the tobacco hornworm moth, Manduca sexta. Insect Biochem Mol Biol 76:118-147|
|Cao, Xiaolong; Jiang, Haobo (2015) Integrated modeling of protein-coding genes in the Manduca sexta genome using RNA-Seq data from the biochemical model insect. Insect Biochem Mol Biol 62:2-10|
|Cao, Xiaolong; He, Yan; Hu, Yingxia et al. (2015) Sequence conservation, phylogenetic relationships, and expression profiles of nondigestive serine proteases and serine protease homologs in Manduca sexta. Insect Biochem Mol Biol 62:51-63|
|Takahashi, Daisuke; Garcia, Brandon L; Kanost, Michael R (2015) Initiating protease with modular domains interacts with ?-glucan recognition protein to trigger innate immune response in insects. Proc Natl Acad Sci U S A 112:13856-61|
|Koenig, Christopher; Hirsh, Ariana; Bucks, Sascha et al. (2015) A reference gene set for chemosensory receptor genes of Manduca sexta. Insect Biochem Mol Biol 66:51-63|
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