Virgilio Bourg - Academia.edu (original) (raw)

Papers by Virgilio Bourg

Research paper thumbnail of Immunogenicity of a novel anti-allergic vaccine based on house dust mite purified allergens and a combination adjuvant in a murine prophylactic model

Frontiers in Allergy

The outer-membrane-derived proteoliposome (PL) of Neisseria meningitidis has been reported as a p... more The outer-membrane-derived proteoliposome (PL) of Neisseria meningitidis has been reported as a potent vaccine adjuvant, inducing a Th1-skewed response. This work aimed to assess the immunogenicity of a novel anti-allergic vaccine candidate based on allergens from Dermatophagoides siboney house dust mite and a combination adjuvant containing PL and Alum. In a preventative experimental setting, BALB/c mice were administered with three doses containing 2 µg of Der s1 and 0.4 µg Der s2 allergen, PL and Alum, at 7 days intervals, by subcutaneous route. Furthermore, mice were subjected to an allergen aerosol challenge for 6 consecutive days. Serum IgE, IgG1, and IgG2a allergen-specific antibodies were assessed by ELISA. Cytokine levels in supernatants of D. siboney stimulated lymphocyte cultures and in bronchoalveolar lavage (BAL) were measured by ELISA. Lung tissues were subjected to histological examination. The vaccine prevented the development of both, systemic (IgE) and local allerg...

Research paper thumbnail of Immunogenicity of a Novel Anti-Allergic Vaccine Based on Purified Allergens from House Dust Mite and a Combination Adjuvant in a Murine Prophylactic Model

SSRN Electronic Journal, 2022

Research paper thumbnail of Endotoxin content in industrially manufactured allergen extracts of House Dust Mites, including Dermatophagoides siboney and Blomia tropicalis

Research paper thumbnail of Preclinical evaluation in mice of the immunogenicity of a novel anti-allergic vaccine, based on Neisseria meningitidis proteoliposome, as adjuvant

Research paper thumbnail of Model of respiratory inflammation in mice provoked by Dermatophagoides siboney allergens

Research paper thumbnail of Remote induction of cellular immune response in mice by anti-meningococcal nanocochleates - nanoproteoliposomes

Science of The Total Environment, 2019

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Distributed under a Creative Commons Attribution-NonCommercial| 4.0 International License

Research paper thumbnail of Safety of a proteoliposome fromNeisseria meningitidesas adjuvant for a house dust mite allergy vaccine

Journal of Immunotoxicology, 2017

The proteoliposome (PL) of Neisseria meningitidis serogroup B has been reported as a safe and pot... more The proteoliposome (PL) of Neisseria meningitidis serogroup B has been reported as a safe and potent vaccine adjuvant, inducing a T H 1-skewed response. The present study describes a pre-clinical safety evaluation of an allergy therapeutic vaccine candidate based on purified allergens from Dermatophagoides siboney house dust mite and PL as adjuvant, both components adsorbed onto aluminum hydroxide gel. Two separate studies of acute toxicity evaluation were performed in mice and rabbits, and two repeatdose studies were conducted in non-sensitized and allergen-sensitized Balb/c mice, respectively. The study in sensitized mice intends to model a therapeutic setting. Aerosolized allergen challenge was used in both settings to model natural respiratory exposure. In the therapeutic setting, mice were administered with three doses containing 2 lg allergen at weekly intervals [subcutaneous route] and subsequently challenged with aerosolized allergen for 6 consecutive days. Parameters of general toxicity effects were assessed via measures of behavior, body weight, food and water consumption, and macroscopic evaluation of organs. Histological examination of organs and the injection site was performed. Potential immunotoxicity effects at the systemic level were assessed by blood eosinophil counting and serum allergen specific IgE by ELISA The vaccine did not produce general or functional toxic effects of significance, at a dose up to 100 lg allergen per kg body weight. An expected local reaction at the injection site was observed, which could be attributed mostly to the immunological effect of aluminum hydroxide. The models implemented here suggest an acceptable safety profile of this vaccine for testing in clinical trials of allergy immunotherapy.

Research paper thumbnail of P063 Stability of immunogenicity of dermatophagoides siboney adjuvanted allergen vaccine

Annals of Allergy, Asthma & Immunology, 2016

Research paper thumbnail of Definition of a Security Value Determined by Limulus Amebocyte Lysate Assay Targeting the Recombinant Human Epidermal Growth Factor

Biopharm International

The limulus amebocyte lysate (LAL) assay is the most widely used test, required by FDA, in qualit... more The limulus amebocyte lysate (LAL) assay is the most widely used test, required by FDA, in quality control for all parenteral drugs in their last-stage manufacturing process previous to the final formulation. However, the rabbit pyrogen test (RPT) is still required in some United States Pharmacopeia (USP) monographs to allow human and animal vaccine batch release. Hence, the correlation between both endotoxin detection tests targeting recombinant human epidermal growth factor (rhEGF) as active molecule was assessed. From the end point chromogenic LAL test initial validation, a correlation coefficient of at least 0.980 in the endotoxin concentration range from 0.5 to 0.06 endotoxin units (EU)/mL was obtained. In the RPT, the specificity of the animal febrile response was previously evaluated. The authors also demonstrated that the LAL enzymatic cascade activation and the induction of the febrile mechanism in rabbits are due to specific bacterial endotoxin contaminants and not linked ...

Research paper thumbnail of 106 Neisseria Meningitidis Derived Proteoliposome as an Adjuvant for Allergen Vaccines

World Allergy Organization Journal, 2012

IgE levels could be recorded, whereas immunizations with OVA-AAVLP rendered background IgE levels... more IgE levels could be recorded, whereas immunizations with OVA-AAVLP rendered background IgE levels only. In accordance, sera of OVA mice which permitted mast cell degranulation upon OVA trigger in a specific b-hexosaminidase release assay, whereas sera of OVA-AAVLP mice did not contain anaphylactogenic antibodies. In an in vivo anaphylaxis experiment, upon intravenous OVA challenge OVA-immunized mice presented significant drop of body temperature, whereas AAVLP-OVA mice remained unaffected. Conclusions: Our study demonstrates the immunogenicity, safety and efficacy of AAVLP as display system of B-cell epitopes for vaccination.

Research paper thumbnail of Modulation of the specific allergic response by mite allergens encapsulated into liposomes

Vaccine, 2006

Liposomes are non toxic and biodegradable lipid vesicles, which are safe and effective adjuvants ... more Liposomes are non toxic and biodegradable lipid vesicles, which are safe and effective adjuvants to induce Th1-skewed immune response. Therefore, the encapsulation of allergens into liposomes could be an attractive alternative for specific allergy immunotherapy. Previously, we obtained DPPC iposomes encapsulating purified allergens from Dermatophagoides siboney, with suitable stability and extremely reduced allergenicity. In this study, Balb/c mice were immunized with allergens ncapsulated into liposomes (LP) and the induced immune response was evaluated in comparison with allergens dissolved in PBS (PBSA) or adsorbed in Alum (AL). The use of Alum or Liposomes induced a strong allergen specific IgG response. However, total IgE serum levels in the AL group were very high, while levels found in LP group were not significantly different from the control group receiving only PBS. The IgG2a/IgG1 subclass ratio was raised in the LP group. Allergen specific IgE, as measured by PCA assay, was similar for LP and PBSA groups, and approximately the half of the reaction size found in AL group. After allergen challenge by inhalation route, peripheral blood and airway eosinophil counts increased significantly in AL, but not in LP group. Additionally, histopathological analysis of lung tissue sections obtained from challenged mice indicated a reduced cellular infiltration in mice immunized with liposomes. These results support the potential use of liposomal formulations for allergen vaccines.

Research paper thumbnail of State of the art in developing allergen vaccines in Cuba: prospects of novel adjuvanted vaccines

Vaccine, 2006

Standardized allergen vaccines have been developed and registered as biopharmaceutical products i... more Standardized allergen vaccines have been developed and registered as biopharmaceutical products in Cuba. Three different vaccines were obtained from the most relevant allergenic mite species: Dermatophagoides pteronvssinus, Dermatophagoides siboney, and Blomia tropicalis. Immuno-analytical methods based on murine monoclonal antibodies and human IgE antibodies were developed for assessing allergenic potency, composition, and stability. Preclinical and clinical studies showed efficacy and safety in diagnostic prick-tests and subcutaneous immunotherapy in asthmatic patients. New approaches are now undertaken in order to develop new adjuvanted formulations based on liposomes or proteoliposomes from Neisseria meningitidis, and purified allergens; aiming to overcome the drawbacks of conventional immunotherapy.

Research paper thumbnail of Novel Anti-Allergic Vaccine Candidate From House Dust Mite Together with a Combination Adjuvant: Treatment or Prevention of Respiratory Allergy

Journal of Allergy and Clinical Immunology, 2013

RATIONALE: Albuterol Spiromax is a novel multi-dose dry powder albuterol inhaler in development f... more RATIONALE: Albuterol Spiromax is a novel multi-dose dry powder albuterol inhaler in development for the treatment of reversible bronchoconstriction and exercise-induced bronchospasm. Current study compares treatment efficacy and safety of two doses of Albuterol Spiromax, and two doses of albuterol delivered via a hydrofluoroalkane (HFA) metered dose inhaler (ProAir HFA) versus placebo. METHODS: Eligibility requirements included: adults and adolescents (> _12 years) with persistent asthma, forced expiratory volume in 1 second (FEV 1) 50-80% predicted and reversible bronchoconstriction demonstrated by > _ 15% increase in FEV 1 following ProAir HFA 180 mcg administration. Study utilized a double-blind double-dummy dose-ranging crossover design and consisted of a 14 day run-in period, five treatment visits separated by 3 to 7 days, and a follow-up visit 3 to 7 days post-treatment. At each treatment visit, patients self-administered one of 5 treatments: Albuterol Spiromax (90 or 180 mcg), HFA-MDI (90 or 180 mcg) or placebo. The primary endpoint was the baseline-adjusted area under the effect curve for FEV 1 for up to 6 hours following each treatment (FEV 1 AUEC 0-6). RESULTS: 72 patients were randomized. The mean FEV 1 AUEC 0-6 for each dose of Albuterol Spiromax and ProAir HFA was significantly greater than placebo (p < 0.0001 for all). Based on the 90% CIs for device differences in FEV 1 AUEC 0-6 , Albuterol Spiromax was comparable to ProAir HFA at each dose level. CONCLUSIONS: Albuterol Spiromax 90 and 180 mcg was found to have bronchodilator efficacy significantly greater than placebo and comparable to the same doses of ProAir HFA in this population of adults and adolescents with persistent asthma.

Research paper thumbnail of Immunogenicity of a novel anti-allergic vaccine based on house dust mite purified allergens and a combination adjuvant in a murine prophylactic model

Frontiers in Allergy

The outer-membrane-derived proteoliposome (PL) of Neisseria meningitidis has been reported as a p... more The outer-membrane-derived proteoliposome (PL) of Neisseria meningitidis has been reported as a potent vaccine adjuvant, inducing a Th1-skewed response. This work aimed to assess the immunogenicity of a novel anti-allergic vaccine candidate based on allergens from Dermatophagoides siboney house dust mite and a combination adjuvant containing PL and Alum. In a preventative experimental setting, BALB/c mice were administered with three doses containing 2 µg of Der s1 and 0.4 µg Der s2 allergen, PL and Alum, at 7 days intervals, by subcutaneous route. Furthermore, mice were subjected to an allergen aerosol challenge for 6 consecutive days. Serum IgE, IgG1, and IgG2a allergen-specific antibodies were assessed by ELISA. Cytokine levels in supernatants of D. siboney stimulated lymphocyte cultures and in bronchoalveolar lavage (BAL) were measured by ELISA. Lung tissues were subjected to histological examination. The vaccine prevented the development of both, systemic (IgE) and local allerg...

Research paper thumbnail of Immunogenicity of a Novel Anti-Allergic Vaccine Based on Purified Allergens from House Dust Mite and a Combination Adjuvant in a Murine Prophylactic Model

SSRN Electronic Journal, 2022

Research paper thumbnail of Endotoxin content in industrially manufactured allergen extracts of House Dust Mites, including Dermatophagoides siboney and Blomia tropicalis

Research paper thumbnail of Preclinical evaluation in mice of the immunogenicity of a novel anti-allergic vaccine, based on Neisseria meningitidis proteoliposome, as adjuvant

Research paper thumbnail of Model of respiratory inflammation in mice provoked by Dermatophagoides siboney allergens

Research paper thumbnail of Remote induction of cellular immune response in mice by anti-meningococcal nanocochleates - nanoproteoliposomes

Science of The Total Environment, 2019

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific re... more HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés. Distributed under a Creative Commons Attribution-NonCommercial| 4.0 International License

Research paper thumbnail of Safety of a proteoliposome fromNeisseria meningitidesas adjuvant for a house dust mite allergy vaccine

Journal of Immunotoxicology, 2017

The proteoliposome (PL) of Neisseria meningitidis serogroup B has been reported as a safe and pot... more The proteoliposome (PL) of Neisseria meningitidis serogroup B has been reported as a safe and potent vaccine adjuvant, inducing a T H 1-skewed response. The present study describes a pre-clinical safety evaluation of an allergy therapeutic vaccine candidate based on purified allergens from Dermatophagoides siboney house dust mite and PL as adjuvant, both components adsorbed onto aluminum hydroxide gel. Two separate studies of acute toxicity evaluation were performed in mice and rabbits, and two repeatdose studies were conducted in non-sensitized and allergen-sensitized Balb/c mice, respectively. The study in sensitized mice intends to model a therapeutic setting. Aerosolized allergen challenge was used in both settings to model natural respiratory exposure. In the therapeutic setting, mice were administered with three doses containing 2 lg allergen at weekly intervals [subcutaneous route] and subsequently challenged with aerosolized allergen for 6 consecutive days. Parameters of general toxicity effects were assessed via measures of behavior, body weight, food and water consumption, and macroscopic evaluation of organs. Histological examination of organs and the injection site was performed. Potential immunotoxicity effects at the systemic level were assessed by blood eosinophil counting and serum allergen specific IgE by ELISA The vaccine did not produce general or functional toxic effects of significance, at a dose up to 100 lg allergen per kg body weight. An expected local reaction at the injection site was observed, which could be attributed mostly to the immunological effect of aluminum hydroxide. The models implemented here suggest an acceptable safety profile of this vaccine for testing in clinical trials of allergy immunotherapy.

Research paper thumbnail of P063 Stability of immunogenicity of dermatophagoides siboney adjuvanted allergen vaccine

Annals of Allergy, Asthma & Immunology, 2016

Research paper thumbnail of Definition of a Security Value Determined by Limulus Amebocyte Lysate Assay Targeting the Recombinant Human Epidermal Growth Factor

Biopharm International

The limulus amebocyte lysate (LAL) assay is the most widely used test, required by FDA, in qualit... more The limulus amebocyte lysate (LAL) assay is the most widely used test, required by FDA, in quality control for all parenteral drugs in their last-stage manufacturing process previous to the final formulation. However, the rabbit pyrogen test (RPT) is still required in some United States Pharmacopeia (USP) monographs to allow human and animal vaccine batch release. Hence, the correlation between both endotoxin detection tests targeting recombinant human epidermal growth factor (rhEGF) as active molecule was assessed. From the end point chromogenic LAL test initial validation, a correlation coefficient of at least 0.980 in the endotoxin concentration range from 0.5 to 0.06 endotoxin units (EU)/mL was obtained. In the RPT, the specificity of the animal febrile response was previously evaluated. The authors also demonstrated that the LAL enzymatic cascade activation and the induction of the febrile mechanism in rabbits are due to specific bacterial endotoxin contaminants and not linked ...

Research paper thumbnail of 106 Neisseria Meningitidis Derived Proteoliposome as an Adjuvant for Allergen Vaccines

World Allergy Organization Journal, 2012

IgE levels could be recorded, whereas immunizations with OVA-AAVLP rendered background IgE levels... more IgE levels could be recorded, whereas immunizations with OVA-AAVLP rendered background IgE levels only. In accordance, sera of OVA mice which permitted mast cell degranulation upon OVA trigger in a specific b-hexosaminidase release assay, whereas sera of OVA-AAVLP mice did not contain anaphylactogenic antibodies. In an in vivo anaphylaxis experiment, upon intravenous OVA challenge OVA-immunized mice presented significant drop of body temperature, whereas AAVLP-OVA mice remained unaffected. Conclusions: Our study demonstrates the immunogenicity, safety and efficacy of AAVLP as display system of B-cell epitopes for vaccination.

Research paper thumbnail of Modulation of the specific allergic response by mite allergens encapsulated into liposomes

Vaccine, 2006

Liposomes are non toxic and biodegradable lipid vesicles, which are safe and effective adjuvants ... more Liposomes are non toxic and biodegradable lipid vesicles, which are safe and effective adjuvants to induce Th1-skewed immune response. Therefore, the encapsulation of allergens into liposomes could be an attractive alternative for specific allergy immunotherapy. Previously, we obtained DPPC iposomes encapsulating purified allergens from Dermatophagoides siboney, with suitable stability and extremely reduced allergenicity. In this study, Balb/c mice were immunized with allergens ncapsulated into liposomes (LP) and the induced immune response was evaluated in comparison with allergens dissolved in PBS (PBSA) or adsorbed in Alum (AL). The use of Alum or Liposomes induced a strong allergen specific IgG response. However, total IgE serum levels in the AL group were very high, while levels found in LP group were not significantly different from the control group receiving only PBS. The IgG2a/IgG1 subclass ratio was raised in the LP group. Allergen specific IgE, as measured by PCA assay, was similar for LP and PBSA groups, and approximately the half of the reaction size found in AL group. After allergen challenge by inhalation route, peripheral blood and airway eosinophil counts increased significantly in AL, but not in LP group. Additionally, histopathological analysis of lung tissue sections obtained from challenged mice indicated a reduced cellular infiltration in mice immunized with liposomes. These results support the potential use of liposomal formulations for allergen vaccines.

Research paper thumbnail of State of the art in developing allergen vaccines in Cuba: prospects of novel adjuvanted vaccines

Vaccine, 2006

Standardized allergen vaccines have been developed and registered as biopharmaceutical products i... more Standardized allergen vaccines have been developed and registered as biopharmaceutical products in Cuba. Three different vaccines were obtained from the most relevant allergenic mite species: Dermatophagoides pteronvssinus, Dermatophagoides siboney, and Blomia tropicalis. Immuno-analytical methods based on murine monoclonal antibodies and human IgE antibodies were developed for assessing allergenic potency, composition, and stability. Preclinical and clinical studies showed efficacy and safety in diagnostic prick-tests and subcutaneous immunotherapy in asthmatic patients. New approaches are now undertaken in order to develop new adjuvanted formulations based on liposomes or proteoliposomes from Neisseria meningitidis, and purified allergens; aiming to overcome the drawbacks of conventional immunotherapy.

Research paper thumbnail of Novel Anti-Allergic Vaccine Candidate From House Dust Mite Together with a Combination Adjuvant: Treatment or Prevention of Respiratory Allergy

Journal of Allergy and Clinical Immunology, 2013

RATIONALE: Albuterol Spiromax is a novel multi-dose dry powder albuterol inhaler in development f... more RATIONALE: Albuterol Spiromax is a novel multi-dose dry powder albuterol inhaler in development for the treatment of reversible bronchoconstriction and exercise-induced bronchospasm. Current study compares treatment efficacy and safety of two doses of Albuterol Spiromax, and two doses of albuterol delivered via a hydrofluoroalkane (HFA) metered dose inhaler (ProAir HFA) versus placebo. METHODS: Eligibility requirements included: adults and adolescents (> _12 years) with persistent asthma, forced expiratory volume in 1 second (FEV 1) 50-80% predicted and reversible bronchoconstriction demonstrated by > _ 15% increase in FEV 1 following ProAir HFA 180 mcg administration. Study utilized a double-blind double-dummy dose-ranging crossover design and consisted of a 14 day run-in period, five treatment visits separated by 3 to 7 days, and a follow-up visit 3 to 7 days post-treatment. At each treatment visit, patients self-administered one of 5 treatments: Albuterol Spiromax (90 or 180 mcg), HFA-MDI (90 or 180 mcg) or placebo. The primary endpoint was the baseline-adjusted area under the effect curve for FEV 1 for up to 6 hours following each treatment (FEV 1 AUEC 0-6). RESULTS: 72 patients were randomized. The mean FEV 1 AUEC 0-6 for each dose of Albuterol Spiromax and ProAir HFA was significantly greater than placebo (p < 0.0001 for all). Based on the 90% CIs for device differences in FEV 1 AUEC 0-6 , Albuterol Spiromax was comparable to ProAir HFA at each dose level. CONCLUSIONS: Albuterol Spiromax 90 and 180 mcg was found to have bronchodilator efficacy significantly greater than placebo and comparable to the same doses of ProAir HFA in this population of adults and adolescents with persistent asthma.