With the growing importance of the black soldier fly(Hermetia illucens)for both sustainable food production and waste management as well as for science,a great demand of understanding its immune system arises.Here,we ...With the growing importance of the black soldier fly(Hermetia illucens)for both sustainable food production and waste management as well as for science,a great demand of understanding its immune system arises.Here,we present the first description of the circulating larval hemocytes with special emphasis on uptake of microorganisms and distinguishing hemocyte types.With histological,zymographic,and cytometric methods and with a set of hemocyte binding lectins and antibodies,the hemocytes of H.illucens are identified as plasmatocytes,crystal cells,and putative prohemocytes.Total hemocyte counts(THC)are determined,and methods for THC determination are compared.Approximately 1100 hemocytes per microliter hemolymph are present in naive animals,while hemocyte density decreases dramatically shortly after wounding,indicating a role of hemocytes in response to wounding(and immune response in general).The determination of the relative abundance of each hemocyte type(differential hemocyte count,DHC)revealed that plasmatocytes are highly abundant,whereas prohemocytes and crystal cells make up only a small percentage of the circulating cells.Plasmatocytes are not only the most abundant but also the professional phagocytes in H.illucens.They rapidly engulf and take up bacteria both in vivo and in vitro,indicating a very potent cellular defense against invading pathogens.Larger bioparticles such as yeasts are also removed from circulation by phagocytosis,but slower than bacteria.This is the first analysis of the potent cellular immune response in the black soldier fly,and a first toolbox that helps to identify hemocyte(types)is presented.展开更多
We here present a detailed study of the ligand-receptor interactions between single and triple-helical strands of collagen and the α2A domain of integrin(α2A),providing valuable new insights into the mechanisms and ...We here present a detailed study of the ligand-receptor interactions between single and triple-helical strands of collagen and the α2A domain of integrin(α2A),providing valuable new insights into the mechanisms and dynamics of collagen-integrin binding at a sub-molecular level.The occurrence of single and triple-helical strands of the collagen fragments was scrutinized with atom force microscopy(AFM)techniques.Strong interactions of the triple-stranded fragments comparable to those of collagen can only be detected for the 42mer triple-helical collagen-like peptide under study(which contains 42 amino acid residues per strand)by solid phase assays as well as by surface plasmon resonance(SPR)measurements.However,changes in NMR signals during titration and characteristic saturation transfer difference(STD)NMR signals are also detectable whenα2A is added to a solution of the 21mer single-stranded collagen fragment.Molecular dynamics(MD)simulations employing different sets of force field parameters were applied to study the interaction between triple-helical or single-stranded collagen fragments withα2A.It is remarkable that even single-stranded collagen fragments can form various complexes withα2A showing significant differences in the complex stability with identical ligands.The results of MD simulations are in agreement with the signal alterations in our NMR experiments,which are indicative of the formation of weak complexes between single-stranded collagen andα2A in solution.These results provide useful information concerning possible interactions ofα2A with small collagen fragments that are of relevance to the design of novel therapeutic A-domain inhibitors.展开更多
基金We wish to thank Prof.Herwig Gutzeit for valuable discussions and providing antibody stocks.We would like to express our gratitude to Dr.Alexander Froschauer and Prof.Klaus Reinhardt who hosted the work in their laboratories,to Prof.Thorsten Mascher and Prof.Christian Dahmann for allowing us to use their laboratory equipment,and Dr.Diana Wolf who provided bacteria strains.We thank Dr.Uwe Töpfer for valuable discussions and assistance in microscopy,Dennis Höfling for Hermetia breeding,and Katharina Starke,Yvonne Henker and Christin Froschauer for assistance in the laboratory.We thank the two anonymous reviewers for their helpful comments that improved the quality of the manuscript significantly.
文摘With the growing importance of the black soldier fly(Hermetia illucens)for both sustainable food production and waste management as well as for science,a great demand of understanding its immune system arises.Here,we present the first description of the circulating larval hemocytes with special emphasis on uptake of microorganisms and distinguishing hemocyte types.With histological,zymographic,and cytometric methods and with a set of hemocyte binding lectins and antibodies,the hemocytes of H.illucens are identified as plasmatocytes,crystal cells,and putative prohemocytes.Total hemocyte counts(THC)are determined,and methods for THC determination are compared.Approximately 1100 hemocytes per microliter hemolymph are present in naive animals,while hemocyte density decreases dramatically shortly after wounding,indicating a role of hemocytes in response to wounding(and immune response in general).The determination of the relative abundance of each hemocyte type(differential hemocyte count,DHC)revealed that plasmatocytes are highly abundant,whereas prohemocytes and crystal cells make up only a small percentage of the circulating cells.Plasmatocytes are not only the most abundant but also the professional phagocytes in H.illucens.They rapidly engulf and take up bacteria both in vivo and in vitro,indicating a very potent cellular defense against invading pathogens.Larger bioparticles such as yeasts are also removed from circulation by phagocytosis,but slower than bacteria.This is the first analysis of the potent cellular immune response in the black soldier fly,and a first toolbox that helps to identify hemocyte(types)is presented.
文摘We here present a detailed study of the ligand-receptor interactions between single and triple-helical strands of collagen and the α2A domain of integrin(α2A),providing valuable new insights into the mechanisms and dynamics of collagen-integrin binding at a sub-molecular level.The occurrence of single and triple-helical strands of the collagen fragments was scrutinized with atom force microscopy(AFM)techniques.Strong interactions of the triple-stranded fragments comparable to those of collagen can only be detected for the 42mer triple-helical collagen-like peptide under study(which contains 42 amino acid residues per strand)by solid phase assays as well as by surface plasmon resonance(SPR)measurements.However,changes in NMR signals during titration and characteristic saturation transfer difference(STD)NMR signals are also detectable whenα2A is added to a solution of the 21mer single-stranded collagen fragment.Molecular dynamics(MD)simulations employing different sets of force field parameters were applied to study the interaction between triple-helical or single-stranded collagen fragments withα2A.It is remarkable that even single-stranded collagen fragments can form various complexes withα2A showing significant differences in the complex stability with identical ligands.The results of MD simulations are in agreement with the signal alterations in our NMR experiments,which are indicative of the formation of weak complexes between single-stranded collagen andα2A in solution.These results provide useful information concerning possible interactions ofα2A with small collagen fragments that are of relevance to the design of novel therapeutic A-domain inhibitors.
