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Sikora AE, Gomez C, Le Van A, Baarda BI, Darnell S, Martinez FG, Zielke RA, Bonventre JA, Jerse AE. A novel gonorrhea vaccine composed of MetQ lipoprotein formulated with CpG shortens experimental murine infection. Vaccine 2020; 38:8175-8184. [PMID: 33162204 DOI: 10.1016/j.vaccine.2020.10.077] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Revised: 10/15/2020] [Accepted: 10/23/2020] [Indexed: 11/18/2022]
Abstract
Bacterial surface lipoproteins are emerging as attractive vaccine candidates due to their biological importance and the feasibility of their large-scale production for vaccine manufacturing. The global prevalence of gonorrhea, resistance to antibiotics, and serious consequences to reproductive and neonatal health necessitate development of effective vaccines. Reverse vaccinology identified the surface-displayed L-methionine binding lipoprotein MetQ (NGO2139) and its homolog GNA1946 (NMB1946) as gonococcal and meningococcal vaccine candidates, respectively. Here, we assessed the suitability of MetQ for inclusion in a gonorrhea vaccine by examining MetQ conservation, its function inNeisseria gonorrhoeae (Ng) pathogenesis, and its ability to induce protective immune responses using a female murine model of lower genital tract infection. In-depth bioinformatics, phylogenetics and mapping the most prevalent Ng polymorphic amino acids to the GNA1946 crystal structure revealed remarkable MetQ conservation: ~97% Ng isolates worldwide possess a single MetQ variant. Mice immunized with rMetQ-CpG (n = 40), a vaccine containing a tag-free version of MetQ formulated with CpG, exhibited robust, antigen-specific antibody responses in serum and at the vaginal mucosae including IgA. Consistent with the activity of CpG as a Th1-stimulating adjuvant, the serum IgG1/IgG2a ratio of 0.38 suggested a Th1 bias. Combined data from two independent challenge experiments demonstrated that rMetQ-CpG immunized mice cleared infection faster than control animals (vehicle, p < 0.0001; CpG, p = 0.002) and had lower Ng burden (vehicle, p = 0.03; CpG, p < 0.0001). We conclude rMetQ-CpG induces a protective immune response that accelerates bacterial clearance from the murine lower genital tract and represents an attractive component of a gonorrhea subunit vaccine.
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Affiliation(s)
- Aleksandra E Sikora
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR 97330, United States; Vaccine and Gene Therapy Institute, Oregon Health & Science University, Beaverton, OR, United States.
| | - Carolina Gomez
- Department of Microbiology and Immunology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, United States
| | - Adriana Le Van
- Department of Microbiology and Immunology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, United States
| | - Benjamin I Baarda
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR 97330, United States
| | - Stephen Darnell
- Department of Microbiology and Immunology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, United States
| | - Fabian G Martinez
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR 97330, United States
| | - Ryszard A Zielke
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR 97330, United States
| | - Josephine A Bonventre
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR 97330, United States
| | - Ann E Jerse
- Department of Microbiology and Immunology, F. Edward Hebert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, United States.
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Makenga G, Bonoli S, Montomoli E, Carrier T, Auerbach J. Vaccine Production in Africa: A Feasible Business Model for Capacity Building and Sustainable New Vaccine Introduction. Front Public Health 2019; 7:56. [PMID: 30949465 PMCID: PMC6435488 DOI: 10.3389/fpubh.2019.00056] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Accepted: 02/25/2019] [Indexed: 11/21/2022] Open
Abstract
Africa has the highest incidence of mortality caused by infectious diseases, and remarkably does not have the capacity to manufacture vaccines that are essential to reduce mortality, improving life expectancy, and promoting economic growth. GAVI has significantly helped introduction of new vaccines in Africa but its sustainability is questionable, and new vaccines introduction post-graduation is rare. Conversely, Africa with its high population and economy growth is an increasing potential market for vaccines. This study aimed to investigate how investment for vaccine production in Africa could be triggered and in which way it could be affordable to most African governments or investors. The investigation was based on a literature review and supplemented by online questionnaires directed to global vaccine stakeholders, African governments and regulatory authorities. In-depth interviews with experts in manufacturing capacity implementation and regulatory capacity building in Africa complemented the study. We also developed business plan scenarios including facility costs calculations and a possible investment plan based on expert opinions and publicly available information from pertinent sources. We saw that, governments in Africa, show interest in vaccine production establishments but only with external support for investment. The common regulatory functionality gap was the quality control laboratories to test vaccine lots before regulatory release. The global vaccine stakeholders showed less preference in investment for vaccine production establishment in Africa. The diverse political ambitions among African governments make it difficult to predict and access the market, a prerequisite for competitive production. A feasible solution could be a small production facility that would use technologies with high yield at low costs of goods to cover the regional needs. A respective antigen production facility is estimated to cost USD 25 Million, an affordable dimension for investors or interested African governments. Attractiveness for the African market is deemed to be high when targeting diseases almost exclusively for Africa (e.g., malaria or invasive non-typhoidal salmonella). With a smart 5 years tangible implementation plan, marketing agreements within existing regional collaborations and with a strong political will, an African government alone or together with an investor could convince global vaccine stakeholders and investors to support.
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Affiliation(s)
- Geofrey Makenga
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
| | | | - Emanuele Montomoli
- Department of Molecular and Developmental Medicine, University of Siena, Siena, Italy
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Baarda BI, Zielke RA, Nicholas RA, Sikora AE. PubMLST for Antigen Allele Mining to Inform Development of Gonorrhea Protein-Based Vaccines. Front Microbiol 2018; 9:2971. [PMID: 30581422 PMCID: PMC6292995 DOI: 10.3389/fmicb.2018.02971] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 11/19/2018] [Indexed: 02/02/2023] Open
Abstract
Neisseria gonorrhoeae (Ng) is a human-specific pathogen and the etiological agent of gonorrhea, a sexually transmitted infection with a significant global health burden. While often asymptomatic, untreated gonorrhea can lead to pelvic inflammatory disease, ectopic pregnancy, infertility, and increased transmission/acquisition of HIV. A protective gonorrhea vaccine may be the only way to control disease transmission in the future due to the inexorable development of antibiotic resistance. Subunit antigens are proven candidates for vaccine development due to their safety, cost-effectiveness, and rapid preparation. To inform protein-based gonorrhea vaccine design by including different antigen variants, herein we present bioinformatics mining of alleles and single nucleotide/amino acid polymorphisms using DNA/protein sequences of all Ng isolates deposited into the PubMLST database and MtrE and BamA as model antigens. We also present phylogenetic analyses that can be performed using sequence data to gain insights into the evolutionary relationships between the polymorphisms found among the population of isolates using a convenient tool: Molecular Evolutionary Genetics Analysis (MEGA) software. Finally, we perform antigen polymorphism mapping onto the MtrE and BamA structures. This methodology can be applied for rational vaccine design to increase vaccine coverage and cross-protection by heteroligand presentation achieved via inclusion of diverse antigen variants and is relevant to over 100 different species and genera deposited into the PubMLST family of databases.
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Affiliation(s)
- Benjamin I. Baarda
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
| | - Ryszard A. Zielke
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
| | - Robert A. Nicholas
- Department of Pharmacology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
- Department of Microbiology and Immunology, The University of North Carolina at Chapel Hill, Chapel Hill, NC, United States
| | - Aleksandra E. Sikora
- Department of Pharmaceutical Sciences, College of Pharmacy, Oregon State University, Corvallis, OR, United States
- Vaccine and Gene Therapy Institute, Oregon Health and Science University, Beaverton, OR, United States
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Kallel H, Kamen AA. Large-scale adenovirus and poxvirus-vectored vaccine manufacturing to enable clinical trials. Biotechnol J 2015; 10:741-7. [PMID: 25914340 DOI: 10.1002/biot.201400390] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2014] [Revised: 03/03/2015] [Accepted: 04/13/2015] [Indexed: 12/11/2022]
Abstract
Efforts to make vaccines against infectious diseases and immunotherapies for cancer have evolved to utilize a variety of heterologous expression systems such as viral vectors. These vectors are often attenuated or engineered to safely deliver genes encoding antigens of different pathogens. Adenovirus and poxvirus vectors are among the viral vectors that are most frequently used to develop prophylactic vaccines against infectious diseases as well as therapeutic cancer vaccines. This mini-review describes the trends and processes in large-scale production of adenovirus and poxvirus vectors to meet the needs of clinical applications. We briefly describe the general principles for the production and purification of adenovirus and poxvirus viral vectors. Currently, adenovirus and poxvirus vector manufacturing methods rely on well-established cell culture technologies. Several improvements have been evaluated to increase the yield and to reduce the overall manufacturing cost, such as cultivation at high cell densities and continuous downstream processing. Additionally, advancements in vector characterization will greatly facilitate the development of novel vectored vaccine candidates.
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Affiliation(s)
- Héla Kallel
- Laboratory of Molecular Microbiology Vaccinology and Biotechnology Development, Viral Vaccines R&D Unit. Institut Pasteur de Tunis, Tunis, Tunisia
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Noyes A, Huffman B, Berrill A, Merchant N, Godavarti R, Titchener-Hooker N, Coffman J, Sunasara K, Mukhopadhyay T. High throughput screening of particle conditioning operations: II. Evaluation of scale-up heuristics with prokaryotically expressed polysaccharide vaccines. Biotechnol Bioeng 2015; 112:1568-82. [PMID: 25727194 DOI: 10.1002/bit.25580] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Revised: 02/15/2015] [Accepted: 02/17/2015] [Indexed: 11/08/2022]
Abstract
Multivalent polysaccharide conjugate vaccines are typically comprised of several different polysaccharides produced with distinct and complex production processes. Particle conditioning steps, such as precipitation and flocculation, may be used to aid the recovery and purification of such microbial vaccine products. An ultra scale-down approach to purify vaccine polysaccharides at the micro-scale would greatly enhance productivity, robustness, and speed the development of novel conjugate vaccines. In part one of this series, we described a modular and high throughput approach to develop particle conditioning processes (HTPC) for biologicals that combines flocculation, solids removal, and streamlined analytics. In this second part of the series, we applied HTPC to industrially relevant feedstreams comprised of capsular polysaccharides (CPS) from several bacterial species. The scalability of HTPC was evaluated between 0.8 mL and 13 L scales, with several different scaling methodologies examined. Clarification, polysaccharide yield, impurity clearance, and product quality achieved with HTPC were reproducible and comparable with larger scales. Particle sizing was the response with greatest sensitivity to differences in processing scale and enabled the identification of useful scaling rules. Scaling with constant impeller tip speed or power per volume in the impeller swept zone offered the most accurate scale up, with evidence that time integration of these values provided the optimal basis for scaling. The capability to develop a process at the micro-scale combined with evidence-based scaling metrics provide a significant advance for purification process development of vaccine processes. The USD system offers similar opportunities for HTPC of proteins and other complex biological molecules.
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Affiliation(s)
- Aaron Noyes
- The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Bernard Katz Building, Gordon Street, London, WC1E 7JE, UK.,Pfizer Bioprocess R&D, Andover, Massachusetts
| | - Ben Huffman
- Pfizer Bioprocess R&D, Chesterfield, Missouri
| | | | | | | | - Nigel Titchener-Hooker
- The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Bernard Katz Building, Gordon Street, London, WC1E 7JE, UK
| | | | | | - Tarit Mukhopadhyay
- The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Bernard Katz Building, Gordon Street, London, WC1E 7JE, UK.
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Noyes A, Godavarti R, Titchener-Hooker N, Coffman J, Mukhopadhyay T. Quantitative high throughput analytics to support polysaccharide production process development. Vaccine 2014; 32:2819-28. [PMID: 24576849 DOI: 10.1016/j.vaccine.2014.02.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
The rapid development of purification processes for polysaccharide vaccines is constrained by a lack of analytical tools current technologies for the measurement of polysaccharide recovery and process-related impurity clearance are complex, time-consuming, and generally not amenable to high throughput process development (HTPD). HTPD is envisioned to be central to the improvement of existing polysaccharide manufacturing processes through the identification of critical process parameters that potentially impact the quality attributes of the vaccine and to the development of de novo processes for clinical candidates, across the spectrum of downstream processing. The availability of a fast and automated analytics platform will expand the scope, robustness, and evolution of Design of Experiment (DOE) studies. This paper details recent advances in improving the speed, throughput, and success of in-process analytics at the micro-scale. Two methods, based on modifications of existing procedures, are described for the rapid measurement of polysaccharide titre in microplates without the need for heating steps. A simplification of a commercial endotoxin assay is also described that features a single measurement at room temperature. These assays, along with existing assays for protein and nucleic acids are qualified for deployment in the high throughput screening of polysaccharide feedstreams. Assay accuracy, precision, robustness, interference, and ease of use are assessed and described. In combination, these assays are capable of measuring the product concentration and impurity profile of a microplate of 96 samples in less than one day. This body of work relies on the evaluation of a combination of commercially available and clinically relevant polysaccharides to ensure maximum versatility and reactivity of the final assay suite. Together, these advancements reduce overall process time by up to 30-fold and significantly reduce sample volume over current practices. The assays help build an analytical foundation to support the advent of HTPD technology for polysaccharide vaccines. It is envisaged that this will lead to an expanded use of Quality by Design (QbD) studies in vaccine process development.
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Affiliation(s)
- Aaron Noyes
- The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK; Pfizer, 1 Burtt Road, Andover, MA 01810, USA
| | | | - Nigel Titchener-Hooker
- The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK
| | | | - Tarit Mukhopadhyay
- The Advanced Centre for Biochemical Engineering, Department of Biochemical Engineering, University College London, Torrington Place, London WC1E 7JE, UK.
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Abstract
Immunization is one of the most powerful preventive measures available. Nurse practitioners can use the social determinants of health framework to analyze structural-level barriers and practice-level clinical microsystems to improve immunization rates.
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Affiliation(s)
- Dian Baker
- California State University, School of Nursing in Sacramento, California, USA
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Josefsberg JO, Buckland B. Vaccine process technology. Biotechnol Bioeng 2012; 109:1443-60. [DOI: 10.1002/bit.24493] [Citation(s) in RCA: 113] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2011] [Revised: 02/24/2012] [Accepted: 02/27/2012] [Indexed: 12/15/2022]
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A Novel Vaccine Using Nanoparticle Platform to Present Immunogenic M2e against Avian Influenza Infection. INFLUENZA RESEARCH AND TREATMENT 2012; 2011:126794. [PMID: 23074652 PMCID: PMC3447297 DOI: 10.1155/2011/126794] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/06/2011] [Revised: 09/24/2011] [Accepted: 10/12/2011] [Indexed: 11/18/2022]
Abstract
Using peptide nanoparticle technology, we have designed two novel vaccine constructs representing M2e in monomeric (Mono-M2e) and tetrameric (Tetra-M2e) forms. Groups of specific pathogen free (SPF) chickens were immunized intramuscularly with Mono-M2e or Tetra-M2e with and without an adjuvant. Two weeks after the second boost, chickens were challenged with 107.2 EID50 of H5N2 low pathogenicity avian influenza (LPAI) virus. M2e-specific antibody responses to each of the vaccine constructs were tested by ELISA. Vaccinated chickens exhibited increased M2e-specific IgG responses for each of the constructs as compared to a non-vaccinated group. However, the vaccine construct Tetra-M2e elicited a significantly higher antibody response when it was used with an adjuvant. On the other hand, virus neutralization assays indicated that immune protection is not by way of neutralizing antibodies. The level of protection was evaluated using quantitative real time PCR at 4, 6, and 8 days post-challenge with H5N2 LPAI by measuring virus shedding from trachea and cloaca. The Tetra-M2e with adjuvant offered statistically significant (P < 0.05) protection against subtype H5N2 LPAI by reduction of the AI virus shedding. The results suggest that the self-assembling polypeptide nanoparticle shows promise as a potential platform for a development of a vaccine against AI.
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Cortes MDLA, Cardoso D, Fitzgerald J, DiFabio JL. Public vaccine manufacturing capacity in the Latin American and Caribbean region: current status and perspectives. Biologicals 2011; 40:3-14. [PMID: 22033155 DOI: 10.1016/j.biologicals.2011.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2011] [Revised: 09/22/2011] [Accepted: 09/22/2011] [Indexed: 10/15/2022] Open
Abstract
The vaccine global market is currently growing at a rate of 16.52%. Nowadays the vaccine manufacturing industry is limited in the sense that not all vaccine manufacturers have the capacity to execute all the steps necessary to produce a successful product. The biological variation inherent to vaccine manufacturing and the initial investment required to bring a vaccine to the market are some of the factors that discourage vaccine manufacturing initiatives. Given the current global context in vaccine innovation and production, and the increasing participation of vaccine manufacturers from developing countries in global markets, this paper aims to review vaccine manufacturing capacity in Latin American and Caribbean (LAC) countries with specific focus on trends in national or public sector manufacturing, presenting current challenges and future opportunities for the sector in meeting national and regional (LAC) needs. Despite the overall low vaccine manufacturing capacity reported within the LAC region within this paper, it is considered that the relatively high and concentrated capacity that exists within a number of countries, combined with political commitment of all countries within the Region, can provide the necessary platform for the continued development of capacity in vaccine development and manufacture within LAC.
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Affiliation(s)
- Maria de los Angeles Cortes
- Pan American Health Organization, Essential Medicines and Biologicals, 525 23rd Street, NW, Washington, DC 20037, USA.
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Fischer NO, Infante E, Ishikawa T, Blanchette CD, Bourne N, Hoeprich PD, Mason PW. Conjugation to nickel-chelating nanolipoprotein particles increases the potency and efficacy of subunit vaccines to prevent West Nile encephalitis. Bioconjug Chem 2010; 21:1018-22. [PMID: 20509624 DOI: 10.1021/bc100083d] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Subunit antigens are attractive candidates for vaccine development, as they are safe, cost-effective, and rapidly produced. Nevertheless, subunit antigens often need to be adjuvanted and/or formulated to produce products with acceptable potency and efficacy. Here, we describe a simple method for improving the potency and efficacy of a recombinant subunit antigen by its immobilization on nickel-chelating nanolipoprotein particles (NiNLPs). NiNLPs are membrane mimetic nanoparticles that provide a delivery and presentation platform amenable to binding any recombinant subunit immunogens featuring a polyhistidine tag. A His-tagged, soluble truncated form of the West Nile virus (WNV) envelope protein (trE-His) was immobilized on NiNLPs. Single inoculations of the NiNLP-trE-His produced superior anti-WNV immune responses and provided significantly improved protection against a live WNV challenge compared to mice inoculated with trE-His alone. These results have broad implications in vaccine development and optimization, as NiNLP technology is well-suited to many types of vaccines, providing a universal platform for enhancing the potency and efficacy of recombinant subunit immunogens.
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Affiliation(s)
- Nicholas O Fischer
- Lawrence Livermore National Laboratory, Livermore, California 94551, USA
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Nicholls EF, Madera L, Hancock REW. Immunomodulators as adjuvants for vaccines and antimicrobial therapy. Ann N Y Acad Sci 2010; 1213:46-61. [PMID: 20946578 DOI: 10.1111/j.1749-6632.2010.05787.x] [Citation(s) in RCA: 67] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A highly effective strategy for combating infectious diseases is to enhance host defenses using immunomodulators, either preventatively, through vaccination, or therapeutically. The effectiveness of many vaccines currently in use is due in part to adjuvants, molecules that have little immunogenicity by themselves but which help enhance and appropriately skew the immune response to an antigen. The development of new vaccines necessitates the development of new types of adjuvants to ensure an appropriate immune response. Herein, we review commonly used vaccine adjuvants and discuss promising adjuvant candidates. We also discuss various other immunomodulators (namely cytokines, Toll-like receptor agonists, and host defense peptides) that are, or have potential to be, useful for antimicrobial therapies that exert their effects by boosting host immune responses rather than targeting pathogens directly.
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Affiliation(s)
- Erin F Nicholls
- Center for Microbial Diseases and Immunity Research, University of British Columbia, Vancouver, British Columbia, Canada
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15
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Ferreira JA, Pires C, Paulo M, Azevedo NF, Domingues MR, Vieira MJ, Monteiro MA, Coimbra MA. Bioaccumulation of amylose-like glycans by Helicobacter pylori. Helicobacter 2009; 14:559-70. [PMID: 19889074 DOI: 10.1111/j.1523-5378.2009.00725.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Helicobacter pylori cell surface is composed of lipopolysaccharides (LPSs) yielding structures homologous to mammalian Lewis O-chains blood group antigens. These structures are key mediators in the definition of host-microbial interactions and known to change their expression pattern in response to environmental pressure. AIMS The present work is focused on the identification of new H. pylori cell-surface glycosides. Special attention is further devoted to provide insights on the impact of in vitro subcultivation on H. pylori cell-surface phenotypes. METHODS Cell-surface glycans from H. pylori NCTC 11637 and two clinical isolates were recovered from the aqueous phase resulting from phenol:water extraction of intact bacteria. They were evaluated in relation to their sugars and glycosidic-linkages composition by CG-MS, size-exclusion chromatography, NMR, and Mass Spectrometry. H. pylori glycan profile was also monitored during subcultivation in vitro in agar and F12 liquid medium. RESULTS All three studied strains produce LPS expressing Lewis epitopes and express bioaccumulate amylose-like glycans. Bioaccumulation of amylose was found to be enhanced with the subcultivation of the bacterium on agar medium and accompanied by a decrease in the expression of LPS O-chains. In contrast, during exponential growth in F12 liquid medium, an opposite behavior is observed, that is, there is an increase in the overall amount of LPS and decrease in amylose content. CONCLUSIONS This work shows that under specific environmental conditions, H. pylori expresses a phase-variable cell-surface alpha-(1-->4)-glucose moiety.
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Affiliation(s)
- José A Ferreira
- Departamento de Química da Universidade de Aveiro, Campus de Santiago, Aveiro, Portugal
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Rational Design of Multiple TB Antigens TB10.4 and TB10.4-Ag85B as Subunit Vaccine Candidates Against Mycobacterium Tuberculosis. Pharm Res 2009; 27:224-34. [DOI: 10.1007/s11095-009-9995-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Accepted: 10/12/2009] [Indexed: 10/20/2022]
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