Publications by authors named "Eduardo Santos da Silva"

8 Publications

  • Page 1 of 1

Ozonized Water in Microbial Control: Analysis of the Stability, In Vitro Biocidal Potential, and Cytotoxicity.

Biology (Basel) 2021 Jun 12;10(6). Epub 2021 Jun 12.

University Center SENAI/CIMATEC, SENAI Institute of Innovation in Health Advanced Systems (ISI SAS), Salvador 41650-010, Bahia, Brazil.

O dissolved in water (or ozonized water) has been considered a potent antimicrobial agent, and this study aimed to test this through microbiological and in vitro assays. The stability of O was accessed following modifications of the physicochemical parameters of water, such as the temperature and pH, with or without buffering. Three concentrations of O (0.4, 0.6, and 0.8 ppm) dissolved in water were tested against different microorganisms, and an analysis of the cytotoxic effects was also conducted using the human ear fibroblast cell line (Hfib). Under the physicochemical conditions of 4 °C and pH 5, O remained the most stable and concentrated compared to pH 7 and water at 25 °C. Exposure to ozonized water resulted in high mortality rates for , , , , and . Scanning electron micrograph images indicate that the effects on osmotic stability due to cell wall lysis might be one of the killing mechanisms of ozonized water. The biocidal agent was biocompatible and presented no cytotoxic effect against Hfib cells. Therefore, due to its cytocompatibility and biocidal action, ozonized water can be considered a viable alternative for microbial control, being possible, for example, its use in disinfection processes.
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June 2021

Purification and characterisation of the dimeric group 12 allergen from Blomia tropicalis heterologously expressed by Escherichia coli Top10F´.

Mol Biol Rep 2021 Apr 29;48(4):3405-3416. Epub 2021 Apr 29.

Department of Biointeraction, Federal University of Bahia, Salvador, Brazil.

Successful research in the wide-ranging field of allergy is usually achieved by definition not only of physicochemical and immunological properties of natural, but also recombinant allergens. Blomia tropicalis mite is a well-known source for various groups of hypersensitivity-causing proteins. The goal of the present work was to produce, purify and characterise by in silico, biochemical and immunological methods the recombinant group-12 allergen of B. tropicalis. The recombinant Blo t 12 aggregation capacity as well as the affinity to antibodies from BALB/c immunised mice and B. tropicalis-sensitised human donors were investigated through in silico analyses, dynamic light scattering, SDS-PAGE, ELISA and Western blot. The presence of Blo t 12 within B. tropicalis extracts was also determined by ELISA and Western blot. High concentrations of dimeric rBlo t 12 were detected through SDS-PAGE next to other aggregates and the results were confirmed by data from DLS and Western blot. The YITVM peptide was predicted to be the most aggregation-prone region. The IgE-reactivity of rBlo t 12 was not completely abolished by aggregate formation but it was significantly decreased compared to rBlo t 5, or B. tropicalis extracts. Natural Blo t 12 may naturally dimerises, but it was detected in non-delipidified B. tropicalis extracts in low amounts. Given that this allergen may be a specific marker for B. tropicalis allergy, the recombinant Blo t 12 herein obtained is characterised as a mid-tier allergen in Brazilian atopic patients and may be useful for the improvement in precision allergy molecular diagnostic applications.
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April 2021

A hybrid of two major Blomia tropicalis allergens as an allergy vaccine candidate.

Clin Exp Allergy 2020 07 13;50(7):835-847. Epub 2020 May 13.

Department of Biosciences, University of Salzburg, Salzburg, Austria.

Introduction: Allergen-specific immunotherapy (AIT) represents a curative approach for treating allergies. In the tropical and subtropical regions of the world, Blomia tropicalis (Blo t 5 and Blo t 21) is the likely dominant source of indoor allergens.

Aim: To generate a hypoallergenic Blo t 5/Blo t 21 hybrid molecule that can treat allergies caused by B tropicalis.

Methods: Using in silico design of B tropicalis hybrid proteins, we chose two hybrid proteins for heterologous expression. Wild-type Blo t 5/Blo t 21 hybrid molecule and a hypoallergenic version, termed BTH1 and BTH2, respectively, were purified by ion exchange and size exclusion chromatography and characterized by physicochemical, as well as in vitro and in vivo immunological, experiments.

Results: BTH1, BTH2 and the parental allergens were purified to homogeneity and characterized in detail. BTH2 displayed the lowest IgE reactivity that induced basophil degranulation using sera from allergic rhinitis and asthmatic patients. BTH2 essentially presented the same endolysosomal degradation pattern as the shortened rBlo t 5 and showed a higher resistance towards degradation than the full-length Blo t 5. In vivo immunization of mice with BTH2 led to the production of IgG antibodies that competed with human IgE for allergen binding. Stimulation of splenocytes from BTH2-immunized mice produced higher levels of IL-10 and decreased secretion of IL-4 and IL-5. In addition, BTH2 stimulated T-cell proliferation in PBMCs isolated from allergic patients, with secretion of higher levels of IL-10 and lower levels of IL-5 and IL-13, when compared to parental allergens.

Conclusions And Clinical Relevance: BTH2 is a promising hybrid vaccine candidate for immunotherapy of Blomia allergy. However, further pre-clinical studies addressing its efficacy and safety are needed.
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July 2020

spp. hypoallergens design: what has been achieved so far?

Expert Opin Ther Pat 2020 Mar 8;30(3):163-177. Epub 2020 Jan 8.

Laboratório de Alergia e Acarologia, Instituto de Ciências da Saúde, Universidade Federal da Bahia (UFBA), Salvador, Brazil.

: Allergic illnesses are one of the most prevalent immunological disorders worldwide and house dust mites are important triggers of these diseases. Allergen-specific immunotherapy (AIT) is an alternative treatment to pharmacotherapy and among its technologies, recombinant hypoallergenic derivatives have shown promising features, turn them into safer and more efficient allergy vaccines.: Patents and scientific publications referring to advances in the design of spp. hypoallergenic molecules. Data were obtained from the Espacenet® and PubMed websites, using different key terms, advanced tools and Boolean operators for searches. The retrieved data were then descriptively analyzed, taking into consideration clinical targets, geographical, temporal, collaborative, and different classification aspects of the productions.: Joint advances of molecular biology, genetic engineering, and bioinformatics technologies led to progresses in the design of spp. hypoallergenic derivatives. Collaborative networks seem to be an interesting way not only to improve technologies in AIT but also to boost the number of patents, publications, and grants for researchers. The observed trend for the use of hypoallergenic hybrid molecules was a fundamental AIT advance and this type of molecule appears to be a more attractive product for companies and more convenient, efficient, and safer allergy immunotherapy for patients.
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March 2020

Proteomic Analysis Reveals Allergen Variability among Breeds of the Dust Mite Blomia tropicalis.

Int Arch Allergy Immunol 2019 27;180(3):159-172. Epub 2019 Sep 27.

Laboratório de Alergia e Acarologia, Departamento de Ciências da Biointeração, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, Brazil,

Background: The dawn of the "omics" technologies has changed allergy research, increasing the knowledge and identification of new allergens. However, these studies have been almost restricted to Dermatophagoides spp. Although Blomia tropicalis has long been established as a clinically important source of allergens, a thorough proteomic characterization is still lacking for this dust mite.

Objective: To increase knowledge of B. tropicalis allergens through proteomic analysis.

Methods: Eleven in-bred lineages of B. tropicalis were obtained from 11 unique different pregnant females. Their somatic extracts were analyzed and compared with a commercially available extract by liquid chromatography tandem mass spectrometry (LC-MS/MS).

Results: Considerable differences in the protein expression profiles were found among the breeds, and most of them displayed higher expression levels of major allergens than the commercially available extract. Blo t 2 was the most prominent allergenic protein in the analyzed extracts. Six identified allergens and 14 isoforms have not yet been recognized by IUIS. Conversely, 3 previously recognized B. tropicalis allergens were not found.

Conclusions: The clear impact of inbreeding on allergen content shown by our study leads us to conclude that the quantification and/or identification of allergens from in-bred lines should be routinely considered for mite cultivation in order to select breeds with higher amounts of major allergens. In this sense, LC-MS/MS may be a useful method to achieve this quality control for research and commercial purposes.
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December 2019

Allergens of Blomia tropicalis: An Overview of Recombinant Molecules.

Int Arch Allergy Immunol 2017 29;172(4):203-214. Epub 2017 Apr 29.

Laboratório de Alergia e Acarologia, Instituto de Ciências da Saúde, Universidade Federal da Bahia, Salvador, Brazil.

Allergic diseases are considered a major problem for healthcare systems in both developed and developing countries. House dust mites are well-known triggers of allergic manifestations. While the Dermatophagoides genus is widely distributed globally, Blomia tropicalis is the most prominent mite species in the tropical and subtropical regions of the world. Over the last decades, an increase in sensitization rates to B. tropicalis has been reported, leading to increased research efforts on Blomia allergens. In fact, 8 new allergens have been identified and characterized to different degrees. Here, we provide an overview of recent developments concerning the identification and production of recombinant Blomia allergens, as well as their structural and immunological characterization. Although considerable progress has been achieved, detailed molecule-based studies are still needed to better define the clinical relevance of Blomia allergens. Thus, the establishment of a well-standardized and fully characterized panel of allergens remains a challenge for the development of better diagnosis and therapy of allergic diseases induced by B. tropicalis.
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August 2017

Advances in patent applications related to allergen immunotherapy.

Expert Opin Ther Pat 2016 Jun 27;26(6):657-68. Epub 2016 Apr 27.

a Instituto de Ciências da Saúde - ICS , Universidade Federal da Bahia (UFBA) , Salvador , Bahia , Brazil.

Introduction: Allergies are among the most prevalent chronic diseases worldwide. Allergen-specific immunotherapy is used as an alternative treatment to pharmacotherapy. These immunotherapies are performed with crude extracts, which have disadvantages when compared to the new approaches, among them are recombinant proteins and hypoallergens. This review aims to assess immunotherapy for allergies through patent application analysis spanning recent decades.

Areas Covered: Patents referring to allergen immunotherapies used in allergy treatment. Data were obtained from the Espacenet® website, using the Cooperative Patent Classification (CPC) system. Two-hundred-and-one patent applications were analyzed, taking into consideration their classification by the type of technology and applicant.

Expert Opinion: Allergen-specific immunotherapy represents the only potentially curative therapeutic intervention for the treatment of allergic diseases. The extract-based immunotherapy is being replaced by the use of recombinant allergens, highlighting the hypoallergenic forms, which have low IgE-binding while retaining T-cell reactivity. It is expected that the development of hypoallergens will expand the scope of allergen-specific immunotherapy, especially if associated with alternative systems for expression and delivery systems with future potential. Furthermore, these new developments will likely address the problem of long-term protocols in allergen-specific immunotherapy, thus allowing better patient adherence and compliance.
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June 2016