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Costa BH, Rezende AK, Costa L, Neves GFM, Shimano AC, de Oliveira Penoni Á, Carvalho CR, Costa RA, de Alvarenga EC. Systemic effects of oral tolerance in bone healing. Sci Rep 2023; 13:6296. [PMID: 37072616 PMCID: PMC10113372 DOI: 10.1038/s41598-023-33591-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2022] [Accepted: 04/15/2023] [Indexed: 05/03/2023] Open
Abstract
Bone fractures cause acute inflammation that, despite being important for initial repair, may delay the healing of the damaged bone. Parenteral injection of dietary protein has been shown to decrease inflammation and accelerate the repair of skin wounds and other inflammatory pathologies. Thus, our aim was to evaluate whether the intraperitoneal (i.p.) immunization with zein, an abundant protein in rodent chow, would favor bone healing. Wistar rats received i.p. immunization: saline (SG), adjuvant (AG) and zein associated with adjuvant (ZG). Then, a 2 mm of defect bone was performed on the right tibia, and on days 7, 14, 28 and 45 thereafter, analyses were performed. The results showed that the injection of zein reduced inflammation without impairing bone mineralization. Moreover, biomechanical tests demonstrated higher levels of maximum force (N) in ZG, indicating better mechanical resistance in relation to the others. The computerized tomography also indicated lower levels of medullary content in the ZG than in the SG, suggesting the absence of trabeculae in the medullary region in the ZG. These findings suggest that the injection of zein in previously tolerated animals may improve bone repair, leading to mechanically functional bone formation.
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Affiliation(s)
- Bruno Henrique Costa
- Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Praça Dom Helvécio 74, São João del Rei, Minas Gerais, 36301-160, Brazil
| | - Alisson Kennedy Rezende
- Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Praça Dom Helvécio 74, São João del Rei, Minas Gerais, 36301-160, Brazil
| | - Lais Costa
- Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Praça Dom Helvécio 74, São João del Rei, Minas Gerais, 36301-160, Brazil
| | - Gabrielle Fernanda Monteiro Neves
- Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Praça Dom Helvécio 74, São João del Rei, Minas Gerais, 36301-160, Brazil
| | - Antônio Carlos Shimano
- Departamento de Biomecânica, Medicina e Reabilitação do Aparelho Locomotor, Faculdade de Medicina de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, São Paulo, 14049-900, Brazil
| | - Álvaro de Oliveira Penoni
- Departamento das Ciências da Educação Física e Saúde, Universidade Federal de São João del-Rei, São João del Rei, Minas Gerais, 36301-360, Brazil
| | - Claudia Rocha Carvalho
- Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Praça Dom Helvécio 74, São João del Rei, Minas Gerais, 36301-160, Brazil
- Departamento Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, 31270-901, Brazil
| | - Raquel Alves Costa
- Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Praça Dom Helvécio 74, São João del Rei, Minas Gerais, 36301-160, Brazil
| | - Erika Costa de Alvarenga
- Departamento de Ciências Naturais, Universidade Federal de São João Del Rei, Praça Dom Helvécio 74, São João del Rei, Minas Gerais, 36301-160, Brazil.
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Pinheiro-Rosa N, Torres L, Oliveira MDA, Andrade-Oliveira MF, Guimarães MADF, Coelho MM, Alves JDL, Maioli TU, Faria AMC. Oral tolerance as antigen-specific immunotherapy. IMMUNOTHERAPY ADVANCES 2021; 1:ltab017. [PMID: 35919733 PMCID: PMC9327124 DOI: 10.1093/immadv/ltab017] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 07/23/2021] [Accepted: 08/23/2021] [Indexed: 12/19/2022] Open
Abstract
Summary
Oral tolerance is a physiological phenomenon described more than a century ago as a suppressive immune response to antigens that gain access to the body by the oral route. It is a robust and long-lasting event with local and systemic effects in which the generation of mucosally induced regulatory T cells (iTreg) plays an essential role. The idea of using oral tolerance to inhibit autoimmune and allergic diseases by oral administration of target antigens was an important development that was successfully tested in 1980s. Since then, several studies have shown that feeding specific antigens can be used to prevent and control chronic inflammatory diseases in both animal models and clinically. Therefore, oral tolerance can be classified as an antigen-specific form of oral immunotherapy (OIT). In the light of novel findings on mechanisms, sites of induction and factors affecting oral tolerance, this review will focus on specific characteristics of oral tolerance induction and how they impact in its therapeutic application.
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Affiliation(s)
- Natália Pinheiro-Rosa
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Lícia Torres
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Mariana de Almeida Oliveira
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Marcos Felipe Andrade-Oliveira
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Mauro Andrade de Freitas Guimarães
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Monique Macedo Coelho
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Juliana de Lima Alves
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Tatiani Uceli Maioli
- Departamento de Nutrição, Escola de Enfermagem, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Ana M Caetano Faria
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
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Gusmao-Silva G, Aguiar SLF, Miranda MCG, Guimarães MA, Alves JL, Vieira AT, Cara DC, Miyoshi A, Azevedo VA, Oliveira RP, Faria AMC. Hsp65-Producing Lactococcocus lactis Prevents Antigen-Induced Arthritis in Mice. Front Immunol 2020; 11:562905. [PMID: 33072101 PMCID: PMC7538670 DOI: 10.3389/fimmu.2020.562905] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2020] [Accepted: 08/18/2020] [Indexed: 01/22/2023] Open
Abstract
Oral tolerance is the physiological process that enables the immune system to differentiate between harmless dietary and microbiota antigens from pathogen derived antigens. It develops at the mucosal surfaces and can result in local and systemic regulatory and anti-inflammatory effects. Translation of these benefits to the clinical practice faces limitations involving specificity and doses of antigen as well as regimens of feeding. To circumvent these problems, we developed a recombinant Hsp65 delivered by the acid lactic bacteria Lactococcus lactis NCDO 2118 directy in the intestinal mucosa. Hsp65 is a ubiquitous protein overexpressed in inflamed tissues and capable of inducing immunoregulatory mechanisms. L. lactis has probiotic properties and is commonly and safely used in dairy products. In this study, we showed that continuous delivery of HSP65 in the gut mucosa by L. lactis is a potent tolerogenic stimulus inducing regulatory CD4+LAP+ T cells that prevented collagen-induced and methylated bovine serum albumin-induced arthritis in mice. Clinical and histological signs of arthritis were inhibited as well as levels of inflammatory cytokines such as IL-17 and IFN-γ, serum titers of anti-collagen antibodies and rheumatoid factor. Oral administration of L. lactis induced alterations in microbiota composition toward an increased abundance of anaerobic bacteria such as Bifidobacterium and Lactobacillus. Tolerance to HSP65 and arthritis prevention induced by the recombinant L. lactis was associated with increase in IL-10 production by B cells and it was dependent on LAP+ T cells, IL-10 and TLR2 signaling. Therefore, HSP65-producing treatment induced effective tolerance and prevented arthritis development suggesting it can be used as a therapeutic tool for autoimmune diseases.
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Affiliation(s)
- Guilherme Gusmao-Silva
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Sarah Leão Fiorini Aguiar
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Mauro Andrade Guimarães
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Juliana Lima Alves
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Angélica Thomaz Vieira
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Denise Carmona Cara
- Departamento de Morfologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Anderson Miyoshi
- Departamento de Genética, Evolução e Ecologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Vasco Ariston Azevedo
- Departamento de Genética, Evolução e Ecologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Ana Maria Caetano Faria
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Instituto de Investigação em Imunologia, São Paulo, Brazil
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Figliuolo da Paz VR, Figueiredo-Vanzan D, dos Santos Pyrrho A. Interaction and involvement of cellular adhesion molecules in the pathogenesis of Schistosomiasis mansoni. Immunol Lett 2019; 206:11-18. [DOI: 10.1016/j.imlet.2018.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/20/2018] [Accepted: 11/25/2018] [Indexed: 12/11/2022]
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Rocha Pereira AE, Rodrigues MÂ, Novaes RD, Caldas IS, Martins Souza RL, Costa Pereira AA. Lipopolysaccharide-induced acute lung injury in mice chronically infected by Schistosoma mansoni. Exp Parasitol 2017; 178:21-29. [PMID: 28533109 DOI: 10.1016/j.exppara.2017.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 04/04/2017] [Accepted: 05/18/2017] [Indexed: 02/06/2023]
Abstract
We used a murine model of Schistosoma mansoni (SM) infection and lipopolysaccharide (LPS)-induced endotoxicity to investigate if these conditions can interact to modify the pathological manifestations typically observed in each condition. Swiss mice were randomized into four groups: SAL, uninfected; SM, infected; LPS, uninfected + LPS; and SM + LPS, infected + LPS. S. mansoni infection developed over 120 days, after which blood samples and lungs were collected, peritoneal leukocytes were isolated and cultivated for 6 and 24 h after LPS inoculation (1 mL/kg). Infected animals presented marked granulomatous inflammation. LPS exposure transiently modified the profile of leucocyte migration into the lung tissue and increased NO production by isolated leukocytes, without inducing any acute effect on the structure of schistosomiasis granulomas. Beyond modifying lung morphology, S. mansoni and LPS interacted to modulate the circulating levels of cytokines. S. mansoni infection restricted INF-γ upregulation 6 and 24 h after LPS administration. Conversely, 24 h after inoculation, LPS increased IL-2 and IL-5 levels. Our findings indicate that LPS impaired the lung microenvironment by acutely disrupting inflammatory homeostatic mechanisms that control lung schistosomiasis. As schistosomiasis develops as a chronic condition, long-term exposure to endotoxins could aggravate the granulomatous process, an issue that requires further investigation.
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Affiliation(s)
- Amanda Esteves Rocha Pereira
- Institute of Biomedical Sciences, Department of Pathology and Parasitology, Federal University of Alfenas, Minas Gerais, 37130-001, Brazil
| | - Maria Ângela Rodrigues
- Institute of Biomedical Sciences, Department of Pathology and Parasitology, Federal University of Alfenas, Minas Gerais, 37130-001, Brazil
| | - Rômulo Dias Novaes
- Institute of Biomedical Sciences, Department of Structural Biology, Federal University of Alfenas, Minas Gerais, 37130-001, Brazil
| | - Ivo Santana Caldas
- Institute of Biomedical Sciences, Department of Pathology and Parasitology, Federal University of Alfenas, Minas Gerais, 37130-001, Brazil
| | - Raquel Lopes Martins Souza
- Institute of Biomedical Sciences, Department of Pathology and Parasitology, Federal University of Alfenas, Minas Gerais, 37130-001, Brazil
| | - Alessandro Antônio Costa Pereira
- Institute of Biomedical Sciences, Department of Pathology and Parasitology, Federal University of Alfenas, Minas Gerais, 37130-001, Brazil.
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Cantaruti TA, Costa RA, de Souza KS, Vaz NM, Carvalho CR. Indirect effects of immunological tolerance to a regular dietary protein reduce cutaneous scar formation. Immunology 2017; 151:314-323. [PMID: 28295241 DOI: 10.1111/imm.12732] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2016] [Revised: 02/15/2017] [Accepted: 03/06/2017] [Indexed: 12/20/2022] Open
Abstract
Oral tolerance refers to the specific inhibition of immune responsiveness to T-cell-dependent antigens contacted through the oral route before parenteral immunization. Oral tolerance to one protein does not inhibit immune responses to other unrelated proteins, but parenteral injection of tolerated antigens plus adjuvant into tolerant, but not normal, mice inhibits immune responses to antigens injected concomitantly or soon thereafter. The inhibitory effect triggered by parenteral injection of tolerated proteins is known as bystander suppression or indirect effects of oral tolerance. Intraperitoneal injection of ovalbumin (OVA) plus alum adjuvant in OVA-tolerant mice soon before skin injury inhibits inflammation and improves cutaneous wound healing. However, as OVA is not a regular component of mouse chow, we tested whether indirect effects could be triggered by zein, the main protein of corn that is regularly present in mouse chow. We show that intraperitoneal injection of a single dose (10 μg) of zein plus alum adjuvant soon before skin injury in mice reduces leucocyte infiltration but increase the number of T cells and the expression of resistin-like molecule-α (a marker of alternatively activated macrophages) in the wound bed, increases the expression of transforming growth factor-β3 in the newly formed epidermis and reduces cutaneous scar formation. These results suggest that indirect effects of oral tolerance triggered by parenteral injection of regular dietary components may be further explored as one alternative way to promote scarless wound healing.
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Affiliation(s)
| | | | - Kênia Soares de Souza
- Departamento de Morfologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Nelson Monteiro Vaz
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Cláudia Rocha Carvalho
- Departamento de Morfologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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Costa RA, Matos LBO, Cantaruti TA, de Souza KS, Vaz NM, Carvalho CR. Systemic effects of oral tolerance reduce the cutaneous scarring. Immunobiology 2015; 221:475-85. [PMID: 26652243 DOI: 10.1016/j.imbio.2015.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 11/06/2015] [Accepted: 11/07/2015] [Indexed: 02/06/2023]
Abstract
BACKGROUND Immunological tolerance refer to the inhibition of specific immune responsiveness and the ingestion of proteins previous to immunization is a reliable method to induce (oral) tolerance. Parenteral exposure to tolerated antigens, in adjuvant, trigger indirect and systemic effects that inhibits concomitant immune responses to other unrelated antigens and also decrease unrelated inflammatory responses. Interesting, intraperitoneal (i.p.) exposure to orally-tolerated proteins soon before an incisional linear skin wound improves the healing by primary intention in mice. An important clinical and surgical objective is to identify strategies to improve wound healing and reduce scarring. OBJECTIVE To evaluate whether i.p. injection of an orally-tolerated protein improves wound healing by secondary intention and reduce scarring of full-thickness excisional skin injury. METHODS C57Bl/6 mice were turned tolerant to ovalbumin (OVA) by drinking a solution containing OVA; seven days later, they received an i.p. injection of OVA plus Al(OH)3 adjuvant immediately before two full-thickness excisional skin wounds, under anesthesia. The wound healing process was evaluated macro and microscopically after H&E, toluidine blue and Gomori's Trichrome staining. The presence of granulocytes, macrophages, miofibroblasts, fibronectin, collagen I and collagen III was investigated by immunofluorescence and the levels of cytokines by flow cytometry or ELISA. Mice not tolerant to OVA were included as controls. RESULTS The i.p. injection of OVA+Al(OH)3 in mice orally tolerant to OVA reduced the subsequent inflammatory response in the wound bed and the cutaneous scarring. There was a change in the pattern of collagen deposition making it more similar to the pattern observed in intact skin. In tolerant mice, mast cells and granulocytes (Ly-6C/G+), were reduced, while lymphocytes (CD3+) were increased in the wound bed. Time course analysis of Th1/Th2/Th17 cytokines and growth factors showed slightly differences between tolerant and control groups. CONCLUSION Parenteral injection of an orally-tolerated protein has systemic consequences that impair the inflammatory response triggered by skin injury and reduce the cutaneous scarring.
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Affiliation(s)
- Raquel Alves Costa
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Pampulha, Belo Horizonte, MG CEP: 31270-901, Brazil
| | - Liana Biajoli Otoni Matos
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Pampulha, Belo Horizonte, MG CEP: 31270-901, Brazil
| | - Thiago Anselmo Cantaruti
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Pampulha, Belo Horizonte, MG CEP: 31270-901, Brazil
| | - Kênia Soares de Souza
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Pampulha, Belo Horizonte, MG CEP: 31270-901, Brazil
| | - Nelson Monteiro Vaz
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Pampulha, Belo Horizonte, MG CEP: 31270-901, Brazil
| | - Cláudia Rocha Carvalho
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, Pampulha, Belo Horizonte, MG CEP: 31270-901, Brazil.
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Mohamed AH, Osman GY, Salem TA, Elmalawany AM. The hepatoprotective activity of blue green algae in Schistosoma mansoni infected mice. Exp Parasitol 2014; 145:7-13. [PMID: 25016189 DOI: 10.1016/j.exppara.2014.06.016] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 06/07/2014] [Accepted: 06/23/2014] [Indexed: 10/25/2022]
Abstract
This study aims to evaluate the immunomodulatory effects of a natural product, blue green algae (BGA) (100 mg/kg BW), alone or combined with praziquantel PZQ (250 mg/kg BW) on granulomatous inflammation, liver histopathology, some biochemical and immunological parameters in mice infected with Schistosoma mansoni. Results showed that the diameter and number of egg granuloma were significantly reduced after treatment of S. mansoni-infected mice with BGA, PZQ and their combination. The histopathological alterations observed in the liver of S. mansoni-infected mice were remarkably inhibited after BGA treatments. BGA decreased the activities of aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) as well as the level of total protein (TP) while the level of albumin was increased. Treatment of infected mice with BGA, PZQ as well as their combination led to significant elevation in the activities of hepatic antioxidant enzymes glutathione peroxidase (GPX) and glutathione-S-transferase (GST) as compared with control group. Combination of BGA and PZQ resulted in significant reduction in the level of intercellular adhesion molecules-1 (ICAM-1), vascular adhesion molecules-1 (VCAM-1) and tumor necrosis factor-alpha (TNF-α) when compared to those of the S. mansoni-infected group. Overall, BGA significantly inhibited the liver damage accompanied with schistosomiasis, exhibited a potent antioxidant and immunoprotective activities. This study suggests that BGA can be considered as promising for development a complementary and/or alternative medicine against schistosomiasis.
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Affiliation(s)
- Azza H Mohamed
- Zoology Department, Faculty of Science, Menufiya University, Egypt
| | - Gamalat Y Osman
- Zoology Department, Faculty of Science, Menufiya University, Egypt
| | - Tarek A Salem
- Molecular Biology Department, Genetic Engineering and Biotechnology Institute, Sadat City University, Egypt
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Vaz NM, Carvalho CR. On the origin of immunopathology. J Theor Biol 2014; 375:61-70. [PMID: 24937801 DOI: 10.1016/j.jtbi.2014.06.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Revised: 06/02/2014] [Accepted: 06/04/2014] [Indexed: 12/19/2022]
Abstract
Stranded between medicine and experimental biology, immunology is buried in its own problems and remains distant from important areas of current biology, such as evolutionary theory, developmental biology and cognitive sciences. Immunology has treated the living system merely as the place or dimension in which immune activity takes place, inserted on a misleading axis (progressive responsiveness versus no response; memory versus tolerance) which neglects the analysis of a robustly stable dynamics which is always present and is neither tolerance nor immunity-a problem currently approached as one of "regulatory" activity. However, a regulatory response also demands regulation, leading to an endless recursion and the adoption of a stimulus-response framework inevitably drives us away from the physiological processes in which lymphocytes are involved. Herein, we propose that immunological physiology, like everything else in the body is dynamic and conservative. Immunopathology, including inherited immunodeficiencies, severe forms of infectious diseases, allergy and autoimmune diseases, are interferences with this stability which frequently include oligoclonal expansions of T lymphocytes. We suggest that this decrease in clonal diversity results from a loss of the stabilizing connectivity among lymphocytes and are not simply markers of immunopathology, but are rather expressions of basic pathogenic mechanisms. The so-called autoimmune diseases are examples of this disequilibrium. In the last decade the characterization of an enormous and diversified commensal microbiota has posed a new and pressing problem: how to explain the harmonic conviviality with trillions of foreign macromolecules. In addition, robustly stable relations towards macromolecular diet can be established by simple ingestion, a state presently labeled as "oral tolerance", a problem that has been buffered for decades as anti-inflammatory protection of the gut. A major change in terminology is necessary to describe this new panorama. We focus on two important gaps in immunological discussions: (a) the organism, seen simultaneously as the medium with which the immune system is constantly in touch and as the entity that mediates the contact with external materials; and (b) the observer, the immunologist, who operates as a human being in human languaging with other human beings, and characterizes immunological specificity. We acknowledge that we are proposing radical departures from current dogma and that we should justify them. Most of what we propose stem form a way of seeing called Biology of Cognition and Language, that derives from ideas of the neurobiologist/philosopher Humberto Maturana, also known as "autopoiesis theory".
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Affiliation(s)
- Nelson M Vaz
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte 31270-901, MG, Brazil.
| | - Claudia R Carvalho
- Departamento de Morfologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-901, MG, Brazil
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