scholarly journals Importance of Cry Proteins in Biotechnology: Initially a Bioinsecticide, Now a Vaccine Adjuvant

Life ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 999
Author(s):  
Maria Cristina Gonzalez-Vazquez ◽  
Ruth Abril Vela-Sanchez ◽  
Norma Elena Rojas-Ruiz ◽  
Alejandro Carabarin-Lima
Keyword(s):  
Immune Response ◽  
Bacillus Thuringiensis ◽  
Specific Antigen ◽  
Structural Homology ◽  
Insect Larvae ◽  
Cry Protein ◽  
Parasporal Crystal ◽  
Cry Proteins ◽  
Experimental Animal Models ◽  
Specific Antigens

A hallmark of Bacillus thuringiensis bacteria is the formation of one or more parasporal crystal (Cry) proteins during sporulation. The toxicity of these proteins is highly specific to insect larvae, exerting lethal effects in different insect species but not in humans or other mammals. The aim of this review is to summarize previous findings on Bacillus thuringiensis, including the characteristics of the bacterium, its subsequent contribution to biotechnology as a bioinsecticide due to the presence of Cry proteins, and its potential application as an adjuvant. In several studies, Cry proteins have been administered together with specific antigens to immunize experimental animal models. The results have shown that these proteins can enhance immunogenicity by generating an adequate immune response capable of protecting the model against an experimental infectious challenge, whereas protection is decreased when the specific antigen is administered without the Cry protein. Therefore, based on previous results and the structural homology between Cry proteins, these molecules have arisen as potential adjuvants in the development of vaccines for both animals and humans. Finally, a model of the interaction of Cry proteins with different components of the immune response is proposed.

Structural implication of the induced immune response by Bacillus thuringiensis Cry proteins: role of the N-terminal region

2004 ◽  
Vol 41 (12) ◽  
pp. 1177-1183 ◽  
Author(s):  
Gloria Guillermina Guerrero ◽  
Donald H. Dean ◽  
Leticia Moreno-Fierros
Keyword(s):  
Immune Response ◽  
Bacillus Thuringiensis ◽  
Terminal Region ◽  
Cry Proteins

scholarly journals A Bacillus thuringiensis S-Layer Protein Involved in Toxicity against Epilachna varivestis (Coleoptera: Coccinellidae)

2006 ◽  
Vol 72 (1) ◽  
pp. 353-360 ◽  
Author(s):  
Guadalupe Peña ◽  
Juan Miranda-Rios ◽  
Gustavo de la Riva ◽  
Liliana Pardo-López ◽  
Mario Soberón ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Insecticidal Activity ◽  
Pathogenic Bacteria ◽  
Bacillus Sphaericus ◽  
Epilachna Varivestis ◽  
Gene Encoding ◽  
Parasporal Crystal ◽  
Cry Proteins ◽  
Bean Beetle ◽  
Paracrystalline Array

ABSTRACT The use of Bacillus thuringiensis as a biopesticide is a viable alternative for insect control since the insecticidal Cry proteins produced by these bacteria are highly specific; harmless to humans, vertebrates, and plants; and completely biodegradable. In addition to Cry proteins, B. thuringiensis produces a number of extracellular compounds, including S-layer proteins (SLP), that contribute to virulence. The S layer is an ordered structure representing a proteinaceous paracrystalline array which completely covers the surfaces of many pathogenic bacteria. In this work, we report the identification of an S-layer protein by the screening of B. thuringiensis strains for activity against the coleopteran pest Epilachna varivestis (Mexican bean beetle; Coleoptera: Coccinellidae). We screened two B. thuringiensis strain collections containing unidentified Cry proteins and also strains isolated from dead insects. Some of the B. thuringiensis strains assayed against E. varivestis showed moderate toxicity. However, a B. thuringiensis strain (GP1) that was isolated from a dead insect showed a remarkably high insecticidal activity. The parasporal crystal produced by the GP1 strain was purified and shown to have insecticidal activity against E. varivestis but not against the lepidopteran Manduca sexta or Spodoptera frugiperda or against the dipteran Aedes aegypti. The gene encoding this protein was cloned and sequenced. It corresponded to an S-layer protein highly similar to previously described SLP in Bacillus anthracis (EA1) and Bacillus licheniformis (OlpA). The phylogenetic relationships among SLP from different bacteria showed that these proteins from Bacillus cereus, Bacillus sphaericus, B. anthracis, B. licheniformis, and B. thuringiensis are arranged in the same main group, suggesting similar origins. This is the first report that demonstrates that an S-layer protein is directly involved in toxicity to a coleopteran pest.

scholarly journals Expression of the sigma35 and cry2AB genes involved in Bacillus thuringiensis virulence

2009 ◽  
Vol 66 (3) ◽  
pp. 403-409 ◽  
Author(s):  
Ana Maria Guidelli-Thuler ◽  
Irlan Leite de Abreu ◽  
Manoel Victor Franco Lemos
Keyword(s):  
Bacillus Thuringiensis ◽  
Sigma Factor ◽  
The Other ◽  
Insect Larvae ◽  
Cry Protein ◽  
Gene Encoding ◽  
Cdna Sequences ◽  
Low Levels ◽  
High Level ◽  
Developmental Phases

There are several genes involved in Bacillus thuringiensis sporulation. The regulation and expression of these genes results in an upregulation in Cry protein production, and this is responsible for the death of insect larvae infected by Bacillus thuringiensis. Gene expression was monitored in Bacillus thuringiensis during three developmental phases. DNA macroarrays were constructed for selected genes whose sequences are available in the GenBank database. These genes were hybridized to cDNA sequences from B. thuringiensis var. kurstaki HD-1. cDNA probes were synthesized by reverse transcription from B. thuringiensis RNA templates extracted during the exponential (log) growth, stationary and sporulation phases, and labeled with 33PadCTP. Two genes were differentially expressed levels during the different developmental phases. One of these genes is related to sigma factor (sigma35), and the other is a cry gene (cry2Ab). There were differences between the differential levels of expression of various genes and among the expression detected for different combinations of the sigma factor and cry2Ab genes. The maximum difference in expression was observed for the gene encoding sigma35 factor in the log phase, which was also expressed at a high level during the sporulation phase. The cry2Ab gene was only expressed at a high level in the log phase, but at very low levels in the other phases when compared to the sigma35.

scholarly journals Structural, functional, and evolutionary analysis of Cry toxins of Bacillus thuringiensis: an in silico study

2021 ◽  
Vol 31 (1) ◽  
Author(s):  
Sujit Kumar Das ◽  
Sukanta Kumar Pradhan ◽  
Kailash Chandra Samal ◽  
Nihar Ranjan Singh
Keyword(s):  
Bacillus Thuringiensis ◽  
3D Structure ◽  
Evolutionary Relationship ◽  
Functional Domain ◽  
Main Body ◽  
Evolutionary Analysis ◽  
Structural Level ◽  
Cry Protein ◽  
Cry Proteins ◽  
Insect Order

Abstract Background Bacillus thuringiensis (Bt) is a gram-positive spore-forming soil bacterium that synthesizes crystalline (Cry) protein, which is toxic and causing pathogenicity against mainly three insect orders: Coleoptera, Diptera, and Lepidoptera. These crystalline protein inclusions, i.e., δ-endotoxins are successfully used as a bio-control agent against insect pests. Main body A total of 58 various Cry proteins belonging to these 3 insect orders were retrieved from SwissProt database and are categorized into different groups. Structural and functional analysis were performed to understand the functional domain arrangements at sequence level as well as at structural level involving both experimental and predicted 3-dimensional models. Besides, the analysis of evolutionary relationship involving all 58 observed Cry proteins at the sequence, domain, and structural levels were done using different bioinformatics tools. Evolutionary analysis revealed that some Cry proteins having toxicity for a specific insect order are found to be clustered for another different insect order, which concludes that they might have toxicity for more than one insect order. Three-dimensional (3D) structure analysis of both experimental and predicted models revealed that proteins might have toxicity for a specific insect order differ in their structural arrangements and was observed in Cry proteins belonging to 3 different insect orders. Conclusions It could be hypothesized that an inner-molecular domain shift or domain insertion/deletion might have taken place during the evolutionary process, which consequently causes structural and functional divergence of Bt. The study output may be helpful for understanding the diversity as well as specificity of the analyzed insecticidal proteins and their application as a biopesticide in the field of agriculture.

scholarly journals The 60-Kilodalton Protein Encoded byorf2in thecry19AOperon of Bacillus thuringiensis subsp. jegathesan Functions Like a C-Terminal Crystallization Domain

2012 ◽  
Vol 78 (6) ◽  
pp. 2005-2012 ◽  
Author(s):  
J. Eleazar Barboza-Corona ◽  
Hyun-Woo Park ◽  
Dennis K. Bideshi ◽  
Brian A. Federici
Keyword(s):  
Bacillus Thuringiensis ◽  
Mass Range ◽  
Wild Type ◽  
Cry Protein ◽  
Cry Proteins ◽  
Content Type ◽  
Native Promoter ◽  
Orf2 Protein ◽  
Function Expression ◽  
Type Crystal

ABSTRACTThecry19Aoperon ofBacillus thuringiensissubsp.jegathesanencodes two proteins, mosquitocidal Cry19A (ORF1; 75 kDa) and an ORF2 (60 kDa) of unknown function. Expression of thecry19Aoperon in an acrystalliferous strain ofB. thuringiensis(4Q7) yielded one small crystal per cell, whereas no crystals were produced whencry19Aororf2was expressed alone. To determine the function of the ORF2 protein, different combinations of Cry19A, ORF2, and the N- or C-terminal half of Cry1C were synthesized in strain 4Q7. Stable crystalline inclusions of these fusion proteins similar in shape to those in the strain harboring the wild-type operon were observed in sporulating cells. Comparative analysis showed that ORF2 shares considerable amino acid sequence identity with the C-terminal region of large Cry proteins. Together, these results suggest that ORF2 assists in synthesis and crystallization of Cry19A by functioning like the C-terminal domain characteristic of Cry protein in the 130-kDa mass range. In addition, to determine whether overexpression of thecry19Aoperon stabilized its shape and increased Cry19A yield, it was expressed under the control of the strong chimericcyt1A-p/STAB-SD promoter. Interestingly, in contrast to the expression seen with the native promoter, overexpression of the operon yielded uniform bipyramidal crystals that were 4-fold larger on average than the wild-type crystal. In bioassays using the 4th instar larvae ofCulex quinquefasciatus, the strain producing the larger Cry19A crystal showed moderate larvicidal activity that was 4-fold (95% lethal concentration [LC95] = 1.9 μg/ml) more toxic than the activity produced in the strain harboring the wild-type operon (LC95= 8.2 μg/ml).

Fate of Bacillus thuringiensis strains in different insect larvae

2004 ◽  
Vol 50 (11) ◽  
pp. 973-975 ◽  
Author(s):  
Marise Tanaka Suzuki ◽  
Didier Lereclus ◽  
Olivia M. Nagy Arantes
Keyword(s):  
Bacillus Thuringiensis ◽  
Bacterial Growth ◽  
Insect Larvae ◽  
Cry Protein ◽  
Insect Pathogen ◽  
Vegetative Cells ◽  
Crystal Proteins ◽  
Favorable Conditions ◽  
Insecticidal Crystal Proteins

In favorable conditions Bacillus thuringiensis spores germinate and vegetative cells multiply, whereas in unfavorable conditions Bacillus thuringiensis sporulates and produces insecticidal crystal proteins. The development of B. thuringiensis strains was investigated in the larvae of insects belonging to the orders Lepidoptera and Diptera. Bacillus thuringiensis strains able to kill the insects did not always multiply in cadavers. Strains with no specificity to kill the insect sometimes multiplied when the insects were killed mechanically. These results indicate that some insect larvae represent an environment that favors the germination of B. thuringiensis spores and the multiplication of vegetative cells; however, there was no correlation between the toxin specificity and the specificity of the host.Key words: Bacillus thuringiensis, Cry protein, insect pathogen, bacterial growth.

scholarly journals Toxicity and Mode of Action of Bacillus thuringiensis Cry Proteins in the Mediterranean Corn Borer, Sesamia nonagrioides (Lefebvre)

2006 ◽  
Vol 72 (4) ◽  
pp. 2594-2600 ◽  
Author(s):  
Joel González-Cabrera ◽  
Gema P. Farinós ◽  
Silvia Caccia ◽  
Mercedes Díaz-Mendoza ◽  
Pedro Castañera ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Binding Site ◽  
Mode Of Action ◽  
Membrane Vesicles ◽  
Bt Corn ◽  
Sesamia Nonagrioides ◽  
Cry Protein ◽  
Cry Proteins ◽  
Corn Borer ◽  
Mediterranean Countries

ABSTRACT Sesamia nonagrioides is one of the most damaging pests of corn in Spain and other Mediterranean countries. Bt corn expressing the Bacillus thuringiensis Cry1Ab toxin is being grown on about 58,000 ha in Spain. Here we studied the mode of action of this Cry protein on S. nonagrioides (binding to specific receptors, stability of binding, and pore formation) and the modes of action of other Cry proteins that were found to be active in this work (Cry1Ac, Cry1Ca, and Cry1Fa). Binding assays were performed with 125I- or biotin-labeled toxins and larval brush border membrane vesicles (BBMV). Competition experiments indicated that these toxins bind specifically and that Cry1Aa, Cry1Ab, and Cry1Ac share a binding site. Cry1Ca and Cry1Fa bind to different sites. In addition, Cry1Fa binds to Cry1A's binding site with very low affinity and vice versa. Binding of Cry1Ab and Cry1Ac was found to be stable over time, which indicates that the observed binding is irreversible. The pore-forming activity of Cry proteins on BBMV was determined using the voltage-sensitive fluorescent dye DiSC3(5). Membrane permeability increased in the presence of the active toxins Cry1Ab and Cry1Fa but not in the presence of the nonactive toxin Cry1Da. In terms of resistance management, based on our results and the fact that Cry1Ca is not toxic to Ostrinia nubilalis, we recommend pyramiding of Cry1Ab with Cry1Fa in the same Bt corn plant for better long-term control of corn borers.

A Summary of the Third Global Interferon-γ Release Assay Symposium

2013 ◽  
Vol 34 (6) ◽  
pp. 619-624 ◽  
Author(s):  
Antonino Catanzaro ◽  
Charles Daley
Keyword(s):  
Immune Response ◽  
Tuberculin Skin Test ◽  
Skin Test ◽  
Interferon Γ ◽  
Enzyme Linked Immunosorbent Assay ◽  
In Vitro Tests ◽  
The Third ◽  
Specific Antigens ◽  
Ifn Γ

Studies over the past several decades have dramatically increased our understanding of the immune response to Mycobacterium tuberculosis infection, and advances in proteomics and genomics have led to a new class of immune-diagnostic tests, termed interferon-γ (IFN-γ) release assays (IGRAs), which appear to obviate many of the problems encountered with the tuberculin skin test (TST). Worldwide, 2 IGRAs are currently commercially available. QuantiFERON-TB Gold In-Tube (Cellestis) is a third-generation product that uses an enzyme-linked immunosorbent assay to measure IFN-γ generated in whole blood stimulated with M. tuberculosis–specific antigens. T-Spot-TB (Oxford Immunotec) employs enzyme-linked immunosorbent spot technology to enumerate the number of purified lymphocytes that respond to M. tuberculosis–specific antigens by producing IFN-γ. These in vitro tests measure the host immune response to M. tuberculosis–specific antigens, which virtually eliminates false-positive cross reactions caused by bacillus Calmette-Guérin vaccination and/or exposure to environmental nontuberculous mycobacteria that plague the interpretation and accuracy of the tuberculin skin test (TST). The high specificity of IGRAs, together with sensitivity commensurate with or better than that of the TST, promises an accurate diagnosis and the ability to focus tuberculosis-control activities on those who are actually infected with M. tuberculosis. The Third Global Symposium was held over a 3-day period and was presented by the University of California, San Diego, Continuing Medical Education department; slides and sound recordings of each presentation are available at http://cme.ucsd.edu/igras/syllabus.html. A moderated discussion is also available at http://cme.ucsd.edu/igrasvideo. This document provides a summary of the key findings of the meeting, specifically focusing on the use of IGRAs in screening healthcare worker populations.

scholarly journals Serological Assays for Identification of Human Gastric Colonization by Helicobacter pylori Strains Expressing VacA m1 or m2

2007 ◽  
Vol 14 (4) ◽  
pp. 442-450 ◽  
Author(s):  
Chandrabali Ghose ◽  
Guillermo I. Perez-Perez ◽  
Victor J. Torres ◽  
Marialuisa Crosatti ◽  
Abraham Nomura ◽  
...  
Keyword(s):  
Helicobacter Pylori ◽  
Asian American ◽  
Specific Antigen ◽  
Secreted Protein ◽  
Gastric Epithelial Cells ◽  
Allele Specific ◽  
Risk Of Disease ◽  
Specific Antigens ◽  
H Pylori ◽  
Development Of Gastric Cancer

ABSTRACT The Helicobacter pylori vacA gene encodes a secreted protein (VacA) that alters the function of gastric epithelial cells and T lymphocytes. H. pylori strains containing particular vacA alleles are associated with differential risk of disease. Because the VacA midregion may exist as one of two major types, m1 or m2, serologic responses may potentially be used to differentiate between patients colonized with vacA m1- or vacA m2-positive H. pylori strains. In this study, we examined the utility of specific antigens from the m regions of VacA as allele-specific diagnostic antigens. We report that serological responses to P44M1, an H. pylori m1-specific antigen, are observed predominantly in patients colonized with m1-positive strains, whereas responses to VacA m2 antigens, P48M2 and P55M2, are observed in patients colonized with either m1- or m2-positive strains. In an Asian-American population, serologic responses to VacA m region-specific antigens were not able to predict the risk of development of gastric cancer.

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