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Then C, Miyazaki J, Bauer-Panskus A. Deficiencies in the Risk Assessment of Genetically Engineered Bt Cowpea Approved for Cultivation in Nigeria: A Critical Review. PLANTS 2022; 11:plants11030380. [PMID: 35161361 PMCID: PMC8838765 DOI: 10.3390/plants11030380] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 12/29/2021] [Revised: 01/22/2022] [Accepted: 01/25/2022] [Indexed: 12/23/2022]
Abstract
We analyze the application filed for the marketing and cultivation of genetically engineered Bt cowpea (event AAT 709A) approved in Nigeria in 2019. Cowpea (Vigna ungiguiculata) is extensively grown throughout sub-Saharan Africa and consumed by around two hundred million people. The transgenic plants produce an insecticidal, recombinant Bt toxin meant to protect the plants against the larvae of Maruca vitrata, which feed on the plants and are also known as pod borer. Our analysis of the application reveals issues of concern regarding the safety of the Bt toxins produced in the plants. These concerns include stability of gene expression, impact on soil organisms, effects on non-target species and food safety. In addition, we show deficiencies in the risk assessment of potential gene flow and uncontrolled spread of the transgenes and cultivated varieties as well as the maintenance of seed collections. As far as information is publicly available, we analyze the application by referring to established standards of GMO risk assessment. We take the provisions of the Cartagena Protocol on Biosafety (CPB) into account, of which both Nigeria and the EU are parties. We also refer to the EU standards for GMO risk assessment, which are complementary to the provisions of the CPB.
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Roberto Raúl SG, Damaris IA, Ángel de Jesús JC, Leticia MF. Cry1Ac Protoxin Confers Antitumor Adjuvant Effect in a Triple-Negative Breast Cancer Mouse Model by Improving Tumor Immunity. BREAST CANCER: BASIC AND CLINICAL RESEARCH 2022; 16:11782234211065154. [PMID: 35002244 PMCID: PMC8738886 DOI: 10.1177/11782234211065154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 11/17/2021] [Indexed: 12/07/2022] Open
Abstract
The Cry1Ac protoxin from Bacillus thuringiensis is a systemic
and mucosal adjuvant, able to confer protective immunity in different infection
murine models and induce both Th1 and TCD8+ cytotoxic lymphocyte responses,
which are required to induce antitumor immunity. The Cry1Ac toxin, despite
having not being characterized as an adjuvant, has also proved to be immunogenic
and able to activate macrophages. Here, we investigated the potential antitumor
adjuvant effect conferred by the Cry1Ac protoxin and Cry1Ac toxin in a triple
negative breast cancer (TNBC) murine model. First, we evaluated the ability of
Cry1Ac proteins to improve dendritic cell (DC) activation and cellular response
through intraperitoneal (i.p.) coadministration with the 4T1 cellular lysate.
Mice coadministered with the Cry1Ac protoxin showed an increase in the number
and activation of CD11c+MHCII- and CD11c+MHCII+low in the peritoneal
cavity and an increase in DC activation (CD11c+MHCII+) in the spleen. Cry1Ac
protoxin increased the proliferation of TCD4+ and TCD8+ lymphocytes in the
spleen and mesenteric lymph nodes (MLN), while the Cry1Ac toxin only increased
the proliferation of TCD4+ and TCD8+ in the MLN. Remarkably, when tested in the
in vivo TNBC mouse model, prophylactic immunizations with 4T1 lysates plus the
Cry1Ac protoxin protected mice from developing tumors. The antitumor effect
conferred by the Cry1Ac protoxin also increased specific cytotoxic T cell
responses, and prevented the typical tumor-related decrease of T cells
(TCD3+ and TCD4+) as well the increase of myeloid-derived suppressor cells
(MDSC) in spleen. Also in the tumor microenvironment of mice coadministered
twice with Cry1Ac protoxin immunological improvements were found such as
reductions in immunosupressive populations (T regulatory lymphocytes and MDSC)
along with increases in macrophages upregulating CD86. These results show a
differential antitumor adjuvant capability of Cry1Ac proteins, highlighting the
ability of Cry1Ac protoxin to enhance local and systemic tumor immunity in TNBC.
Finally, using a therapeutic approach, we evaluated the coadministration of
Cry1Ac protoxin with doxorubicin. A significant reduction in tumor volume and
lung metastasis was found, with increased intratumoral levels of tumor necrosis
factor-α and IL-6 with respect to the vehicle group, further supporting its
antitumor applicability.
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Affiliation(s)
- Servin-Garrido Roberto Raúl
- Laboratorio de Inmunidad en Mucosas, Unidad de Investigación en Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1 Los Reyes Iztacala CP 54090, Tlalnepantla, Estado de México, México
| | - Ilhuicatzi-Alvarado Damaris
- Laboratorio de Inmunidad en Mucosas, Unidad de Investigación en Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1 Los Reyes Iztacala CP 54090, Tlalnepantla, Estado de México, México
| | - Jiménez-Chávez Ángel de Jesús
- Laboratorio de Inmunidad en Mucosas, Unidad de Investigación en Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1 Los Reyes Iztacala CP 54090, Tlalnepantla, Estado de México, México
| | - Moreno-Fierros Leticia
- Laboratorio de Inmunidad en Mucosas, Unidad de Investigación en Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1 Los Reyes Iztacala CP 54090, Tlalnepantla, Estado de México, México
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Gonzalez-Vazquez MC, Vela-Sanchez RA, Rojas-Ruiz NE, Carabarin-Lima A. Importance of Cry Proteins in Biotechnology: Initially a Bioinsecticide, Now a Vaccine Adjuvant. Life (Basel) 2021; 11:999. [PMID: 34685371 PMCID: PMC8541582 DOI: 10.3390/life11100999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 09/19/2021] [Accepted: 09/19/2021] [Indexed: 11/21/2022] Open
Abstract
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.
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Affiliation(s)
- Maria Cristina Gonzalez-Vazquez
- Centro de Investigaciones en Ciencias Microbiologicas, Instituto de Ciencias, Benemerita Universidad Autonoma de Puebla, Puebla 72000, PU, Mexico; (M.C.G.-V.); (N.E.R.-R.)
| | - Ruth Abril Vela-Sanchez
- Licenciatura en Biotecnología, Benemerita Universidad Autonoma de Puebla, Puebla 72000, PU, Mexico;
| | - Norma Elena Rojas-Ruiz
- Centro de Investigaciones en Ciencias Microbiologicas, Instituto de Ciencias, Benemerita Universidad Autonoma de Puebla, Puebla 72000, PU, Mexico; (M.C.G.-V.); (N.E.R.-R.)
- Licenciatura en Biotecnología, Benemerita Universidad Autonoma de Puebla, Puebla 72000, PU, Mexico;
| | - Alejandro Carabarin-Lima
- Centro de Investigaciones en Ciencias Microbiologicas, Instituto de Ciencias, Benemerita Universidad Autonoma de Puebla, Puebla 72000, PU, Mexico; (M.C.G.-V.); (N.E.R.-R.)
- Licenciatura en Biotecnología, Benemerita Universidad Autonoma de Puebla, Puebla 72000, PU, Mexico;
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Guerrero Manriquez GG, Tuero I. Adjuvants: friends in vaccine formulations against infectious diseases. Hum Vaccin Immunother 2021; 17:3539-3550. [PMID: 34288795 DOI: 10.1080/21645515.2021.1934354] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Infectious diseases represent a major cause of deaths worldwide. No vaccine or effective treatment exists nowadays, especially against intracellular pathogens. The increase in multiple drug and superbug antibiotic resistance strains, excessive medication, or misuse of drugs has prompted the search for other safe and effective alternatives. Consistent with this, adjuvants (Latin word "adjuvare": "help or aid") co-administered (Exo) in vaccines have emerged as a promising alternative to initiate and boost an innate, downstream signal that led to adaptative immune response. Nowadays, a promising model of strong immunogens and adjuvants at mucosal sites are the microbial bacterial toxins. Other adjuvants that are also used and might successfully replace aluminum salts in combination with nanotechnology are CpG-ODN, poly IC, type I IFNs, mRNA platforms. Therefore, in the present review, we focused to revisit the old to the new adjuvants compounds, the properties that make them friends in vaccine formulations against infectious diseases.
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Affiliation(s)
| | - I Tuero
- Faculty of Science and Phylosophy, Universidad Peruana Cayetano Heredia, Lima, Peru
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5
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Santos-Vigil KI, Ilhuicatzi-Alvarado D, García-Hernández AL, Herrera-García JS, Moreno-Fierros L. Study of the allergenic potential of Bacillus thuringiensis Cry1Ac toxin following intra-gastric administration in a murine model of food-allergy. Int Immunopharmacol 2018; 61:185-196. [DOI: 10.1016/j.intimp.2018.05.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Revised: 05/25/2018] [Accepted: 05/29/2018] [Indexed: 02/07/2023]
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Rubio-Infante N, Ilhuicatzi-Alvarado D, Torres-Martínez M, Reyes-Grajeda JP, Nava-Acosta R, González-González E, Moreno-Fierros L. The Macrophage Activation Induced by Bacillus thuringiensis Cry1Ac Protoxin Involves ERK1/2 and p38 Pathways and the Interaction with Cell-Surface-HSP70. J Cell Biochem 2017; 119:580-598. [PMID: 28608568 DOI: 10.1002/jcb.26216] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2017] [Accepted: 06/12/2017] [Indexed: 01/04/2023]
Abstract
Here, we aimed to further characterize the mechanisms involved in protoxin (p) Cry1Ac-induced macrophage activation. We demonstrated that pCry1Ac induces MAPK ERK1/2, p38, and JNK phosphorylation in RAW264.7 macrophages. Because MAPK activation is mainly triggered via ligand-receptor interactions, we focused on the identification of potential pCry1Ac-receptor proteins. Flow cytometry and confocal analysis showed specific saturable pCry1Ac-binding to the macrophage surface and evidenced its internalization via the clathrin-pathway. We performed immunoprecipitation assays and identified by MALDI-TOF-TOF several possible pCry1Ac-binding proteins, such as heat shock proteins (HSPs), vimentin, α-enolase, and actin; whose interaction and presence was confirmed, respectively, by ligand blot and Western blot assays. We also detected cell-surface (cs) pCry1Ac-HSP70 colocalization, so HSP70 was chosen for further characterization. Co-immunoprecipitation with HSP70 antibodies followed by Western blot confirmed the pCry1Ac-HSP70 interaction. Furthermore, pretreatment of RAW264.7 cells with HSP70 antibodies reduced pCry1Ac-induced ERK1 phosphorylation and MCP-1 production; thus suggest the functional participation of csHSP70 in pCry1Ac-induced macrophage activation. csHSP70 also was evaluated in peritoneal-cavity (PerC) macrophages of untreated BALB/c mice, interestingly it was found that the predominant population namely large-peritoneal-macrophages (LPM) displayed csHSP70 + hi. Furthermore, the dynamics of PerC macrophage subsets, LPM, and small-peritoneal macrophages (SPM) were evaluated in response to in vivo pCry1Ac stimuli in presence or not of phenylethynesulfonamide (PES) a functional HSP70 inhibitor. It was found that pCry1Ac increased the proportion of SPM CD11b + F4/80 + lowMHCII + csHSP70 + low and markedly reduced the amount of LPM CD11b + F4/80 + hiMHCII-csHSP70 + hi; while PES, partially suppressed this pCry1Ac-induced effect, further suggesting the participation of HSP70 in macrophage activation process. J. Cell. Biochem. 119: 580-598, 2018. © 2017 Wiley Periodicals, Inc.
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Affiliation(s)
- Nestor Rubio-Infante
- Laboratorio de Inmunidad en Mucosas, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla 54090, Estado de México
| | - Damaris Ilhuicatzi-Alvarado
- Laboratorio de Inmunidad en Mucosas, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla 54090, Estado de México
| | - Marilu Torres-Martínez
- Laboratorio de Inmunidad en Mucosas, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla 54090, Estado de México
| | - Juan Pablo Reyes-Grajeda
- Instituto Nacional de Medicina Genómica, Periférico Sur No. 4809, Colonia Arenal Tepepan, Delegación Tlalpan, 14610, México, DF
| | - Raúl Nava-Acosta
- Laboratorio de Inmunidad en Mucosas, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla 54090, Estado de México
| | - Edith González-González
- Laboratorio de Inmunidad en Mucosas, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla 54090, Estado de México
| | - Leticia Moreno-Fierros
- Laboratorio de Inmunidad en Mucosas, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla 54090, Estado de México
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Mezzomo BP, Miranda-Vilela AL, Grisolia CK. Toxicological Evaluation of a Potential Immunosensitizer for Use as a Mucosal Adjuvant--Bacillus thuringiensis Cry1Ac Spore-Crystals: A Possible Inverse Agonist that Deserves Further Investigation. Toxins (Basel) 2015; 7:5348-58. [PMID: 26690217 PMCID: PMC4690131 DOI: 10.3390/toxins7124881] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 09/15/2015] [Accepted: 10/09/2015] [Indexed: 11/16/2022] Open
Abstract
In addition to their applicability as biopesticides, Bacillus thuringiensis (Bt) Cry1Ac spore-crystals are being researched in the immunology field for their potential as adjuvants in mucosal and parenteral immunizations. We aimed to investigate the hematotoxicity and genotoxicity of Bt spore-crystals genetically modified to express Cry1Ac individually, administered orally (p.o.) or with a single intraperitoneal (i.p.) injection 24 h before euthanasia, to simulate the routes of mucosal and parenteral immunizations in Swiss mice. Blood samples were used to perform hemogram, and bone marrow was used for the micronucleus test. Cry1Ac presented cytotoxic effects on erythroid lineage in both routes, being more severe in the i.p. route, which also showed genotoxic effects. The greater severity noted in this route, mainly at 6.75 mg/kg, as well as the intermediate effects at 13.5 mg/kg, and the very low hematotoxicity at 27 mg/kg, suggested a possible inverse agonism. The higher immunogenicity for the p.o. route, particularly at 27 mg/kg, suggested that at this dose, Cry 1Ac could potentially be used as a mucosal adjuvant (but not in parenteral immunizations, due to the genotoxic effects observed). This potential should be investigated further, including making an evaluation of the proposed inverse agonism and carrying out cytokine profiling.
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Affiliation(s)
- Bélin Poletto Mezzomo
- Department of Genetics and Morphology, Institute of Biological Sciences, University of Brasilia, Brasilia/DF 70.910-900, Brazil.
| | - Ana Luisa Miranda-Vilela
- Department of Genetics and Morphology, Institute of Biological Sciences, University of Brasilia, Brasilia/DF 70.910-900, Brazil.
- Faculty of Medicine, Faciplac, Campus Gama, SIGA Área Especial N° 02 Setor Leste-Gama/DF 72.460-000, Brazil.
| | - Cesar Koppe Grisolia
- Department of Genetics and Morphology, Institute of Biological Sciences, University of Brasilia, Brasilia/DF 70.910-900, Brazil.
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Rubio-Infante N, Moreno-Fierros L. An overview of the safety and biological effects of Bacillus thuringiensis Cry toxins in mammals. J Appl Toxicol 2015; 36:630-48. [PMID: 26537666 DOI: 10.1002/jat.3252] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2015] [Revised: 09/08/2015] [Accepted: 09/09/2015] [Indexed: 12/12/2022]
Abstract
Crystal proteins (Cry) produced during the growth and sporulation phases of Bacillus thuringiensis (Bt) bacterium are known as delta endotoxins. These toxins are being used worldwide as bioinsecticides to control pests in agriculture, and some Cry toxins are used against mosquitoes to control vector transmission. This review summarizes the relevant information currently available regarding the biosafety and biological effects that Bt and its insecticidal Cry proteins elicit in mammals. This work was performed because of concerns regarding the possible health impact of Cry toxins on vertebrates, particularly because Bt toxins might be associated with immune-activating or allergic responses. The controversial data published to date are discussed in this review considering earlier toxicological studies of B. thuringiensis, spores, toxins and Bt crops. We discussed the experimental studies performed in humans, mice, rats and sheep as well as in diverse mammalian cell lines. Although the term 'toxic' is not appropriate for defining the effects these toxins have on mammals, they cannot be considered innocuous, as they have some physiological effects that may become pathological; thus, trials that are more comprehensive are necessary to determine their effects on mammals because knowledge in this field remains limited.
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Affiliation(s)
- Néstor Rubio-Infante
- Laboratorio de Inmunidad en Mucosas, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla, 54090, Estado de México, México
| | - Leticia Moreno-Fierros
- Laboratorio de Inmunidad en Mucosas, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla, 54090, Estado de México, México
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González-González E, García-Hernández AL, Flores-Mejía R, López-Santiago R, Moreno-Fierros L. The protoxin Cry1Ac of Bacillus thuringiensis improves the protection conferred by intranasal immunization with Brucella abortus RB51 in a mouse model. Vet Microbiol 2015; 175:382-8. [DOI: 10.1016/j.vetmic.2014.11.021] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2014] [Revised: 11/20/2014] [Accepted: 11/24/2014] [Indexed: 11/25/2022]
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No adjuvant effect of Bacillus thuringiensis-maize on allergic responses in mice. PLoS One 2014; 9:e103979. [PMID: 25084284 PMCID: PMC4118972 DOI: 10.1371/journal.pone.0103979] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Accepted: 07/09/2014] [Indexed: 11/19/2022] Open
Abstract
Genetically modified (GM) foods are evaluated carefully for their ability to induce allergic disease. However, few studies have tested the capacity of a GM food to act as an adjuvant, i.e. influencing allergic responses to other unrelated allergens at acute onset and in individuals with pre-existing allergy. We sought to evaluate the effect of short-term feeding of GM Bacillus thuringiensis (Bt)-maize (MON810) on the initiation and relapse of allergic asthma in mice. BALB/c mice were provided a diet containing 33% GM or non-GM maize for up to 34 days either before ovalbumin (OVA)-induced experimental allergic asthma or disease relapse in mice with pre-existing allergy. We observed that GM-maize feeding did not affect OVA-induced eosinophilic airway and lung inflammation, mucus hypersecretion or OVA-specific antibody production at initiation or relapse of allergic asthma. There was no adjuvant effect upon GM-maize consumption on the onset or severity of allergic responses in a mouse model of allergic asthma.
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Ibarra-Moreno S, García-Hernández AL, Moreno-Fierros L. Coadministration of protoxin Cry1Ac from Bacillus thuringiensis with metacestode extract confers protective immunity to murine cysticercosis. Parasite Immunol 2014; 36:266-70. [PMID: 24484070 DOI: 10.1111/pim.12103] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2013] [Accepted: 01/23/2014] [Indexed: 02/02/2023]
Abstract
The Bacillus thuringiensis Cry1Ac protoxin (pCry1Ac) is a promising mucosal immunogen and adjuvant that induces protective immunity against Naegleria fowleri and malaria infection models. We determined whether pCry1Ac acted as a protective adjuvant against infection with Taenia crassiceps. BALB/C mice were thrice i.p. immunized with (i) pCry1Ac, (ii) metacestode extract, (iii) extract + pCry1Ac or (iv) vehicle, challenged with metacestodes on day 26 and then sacrificed 35 days later. Cysticerci in the peritoneal cavity were counted, while the serum antibody response and cytokines were analysed after immunization and during infection. Only immunization with pCry1Ac plus extract conferred a significant protection (up to 47%). This group presented fluctuating antibody peaks during infection and the highest IgG1 and IgM titres. Immunization with extract alone elicited high IgG1 and the highest IgG2a responses after 25 days of infection, while nonimmunized mice presented a poor, mixed-Th1/Th2 response during infection. Sharp peaks of TNFα and IFN-γ occurred immediately after the first immunization with extract, especially in the presence of pCry1Ac, but not after the challenge, while in the control and pCry1Ac-alone groups, cytokines were only detected after the challenge. The data support the protective-adjuvant effect of co-administration of pCry1Ac in cysticercosis.
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Affiliation(s)
- S Ibarra-Moreno
- Laboratorio de Inmunidad en Mucosas Unidad de Biomedicina FES-Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla, Estado de México, México
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Moreno-Fierros L, García-Hernández AL, Ilhuicatzi-Alvarado D, Rivera-Santiago L, Torres-Martínez M, Rubio-Infante N, Legorreta-Herrera M. Cry1Ac protoxin from Bacillus thuringiensis promotes macrophage activation by upregulating CD80 and CD86 and by inducing IL-6, MCP-1 and TNF-α cytokines. Int Immunopharmacol 2013; 17:1051-66. [PMID: 24157331 DOI: 10.1016/j.intimp.2013.10.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 10/03/2013] [Accepted: 10/04/2013] [Indexed: 01/17/2023]
Abstract
Bacillus thuringiensis Cry1Ac protoxin (pCry1Ac) is a promising mucosal adjuvant, but its action mechanism is unknown. We examined in vivo whether pCry1Ac promotes the activation of macrophages in the peritoneum, spleen and mesenteric lymph nodes or in the lungs and bronchoalveolar lavage after intraperitoneal or intranasal pCry1Ac administration, respectively, in BALB/c mice. pCry1Ac upregulated the costimulatory molecules CD80 and CD86 in these macrophages, but with distinct kinetics. In vitro stimulation of resident macrophages with pCry1Ac upregulated CD80 and CD86 and enhanced the production of the pro-inflammatory cytokines TNF-α, IL-6 and MCP-1. To investigate whether the pCry1Ac-induced activation was mediated through MAPK pathways, we pretreated RAW 264.7 cells with signaling inhibitors of MEK, JNK and p38 MAPKs (PD98059, SP600125 and SB203580, respectively). pCry1Ac-induced upregulation of CD86 and CD80 was partially inhibited by the MEK inhibitor. While LPS-induced upregulation mechanisms of CD80 and CD86 appear to be different; as these were particularly inhibited by MEK and JNK inhibitors, respectively. pCry1Ac-induced IL-6 and MCP-1 production was especially inhibited with the p38 MAPK inhibitor, whereas TNF-α was only slightly inhibited upon treatment with JNK and p38 MAPK inhibitors. Therefore macrophage stimulation with pCry1Ac induced the upregulation of CD80 and CD86, and the production of IL-6, TNF-α and MCP-1, possibly, through the MEK and p38 MAPK pathways. It also promoted the nuclear translocation of NF-κB p50 and p65, the upregulation of MHC-II, and the activation of T CD4+ cells. These results suggest that pCry1Ac induced macrophage activation through mechanisms which differ partially from the LPS-induced.
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Affiliation(s)
- Leticia Moreno-Fierros
- Laboratorio de Inmunidad en Mucosas, Unidad de Biomedicina, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Avenida de los Barrios 1, Los Reyes Iztacala, Tlalnepantla 54090, Estado de México, México.
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Legorreta-Herrera M, Rivas-Contreras S, Ventura-Gallegos J, Zentella-Dehesa A. Nitric oxide is involved in the upregulation of IFN-γ and IL-10 mRNA expression by CD8⁺ T cells during the blood stages of P. chabaudi AS infection in CBA/Ca mice. Int J Biol Sci 2011; 7:1401-11. [PMID: 22110391 PMCID: PMC3221947 DOI: 10.7150/ijbs.7.1401] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2011] [Accepted: 10/01/2011] [Indexed: 01/17/2023] Open
Abstract
Nitric oxide (NO) is involved in the clearance of several types of bacteria, viruses and parasites. Although the roles of NO and CD8+ T cells in the immune response to malaria have been extensively studied, their actual contributions during the blood stages of malaria infection remain unclear. In this work, we corroborate that serum NO levels are not associated with the in vivo elimination of the blood stages of Plasmodium chabaudi AS. In addition, we show that CD8+ T cells exhibit increased apoptosis and up regulate the expression of TNF-α mRNA on day 4 post-infection and IFN-γ and IL-10 mRNA on day 11 post-infection. Interestingly, only the levels of IFN-γ and IL-10 expression are affected when iNOS is inhibited with aminoguanidine (AG), suggesting that NO could be involved in the activation of CD8+ T cells during the blood stages of plasmodium infection.
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Affiliation(s)
- M Legorreta-Herrera
- Laboratorio de Inmunología Molecular, Facultad de Estudios Superiores Zaragoza, Universidad Nacional Autónoma de México, Batalla 5 de Mayo Esq. Fuerte de Loreto, Iztapalapa 09230, México, D.F. México.
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