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A reference document on Permissible Limits for solvents and buffers during in vitro antimalarial screening. Sci Rep 2018; 8:14974. [PMID: 30297791 PMCID: PMC6175914 DOI: 10.1038/s41598-018-33226-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2018] [Accepted: 09/18/2018] [Indexed: 12/20/2022] Open
Abstract
Antimalarial drug discovery expands on targeted and phenotype-based screening of potential inhibitory molecules to ascertain overall efficacy, phenotypic characteristics and toxicity, prior to exploring pharmacological optimizations. Candidate inhibitors may have varying chemical properties, thereby requiring specific reconstitution conditions to ensure solubility, stability or bioavailability. Hence, a variety of solvents, buffers, detergents and stabilizers become part of antimalarial efficacy assays, all of which, above certain threshold could interfere with parasite viability, invasion or red blood cell properties leading to misinterpretation of the results. Despite their routine use across malaria research laboratories, there is no documentation on non-toxic range for common constituents including DMSO, glycerol, ethanol and methanol. We herein constructed a compatibility reference guide for 14 such chemicals and estimated their Permissible Limit against P. falciparum asexual stages at which viability and replication of parasites are not compromised. We also demonstrate that at the estimated Permissible Limit, red blood cells remain healthy and viable for infection by merozoites. Taken together, this dataset provides a valuable reference tool for the acceptable concentration range for common chemicals during in vitro antimalarial tests.
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Brelsford JB, Plieskatt JL, Yakovleva A, Jariwala A, Keegan BP, Peng J, Xia P, Li G, Campbell D, Periago MV, Correa-Oliveira R, Bottazzi ME, Hotez PJ, Diemert D, Bethony JM. Advances in neglected tropical disease vaccines: Developing relative potency and functional assays for the Na-GST-1/Alhydrogel hookworm vaccine. PLoS Negl Trop Dis 2017; 11:e0005385. [PMID: 28192438 PMCID: PMC5325600 DOI: 10.1371/journal.pntd.0005385] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Revised: 02/24/2017] [Accepted: 02/04/2017] [Indexed: 11/19/2022] Open
Abstract
A new generation of vaccines for the neglected tropical diseases (NTDs) have now advanced into clinical development, with the Na-GST-1/Alhydrogel Hookworm Vaccine already being tested in Phase 1 studies in healthy adults. The current manuscript focuses on the often overlooked critical aspects of NTD vaccine product development, more specifically, vaccine stability testing programs. A key measure of vaccine stability testing is "relative potency" or the immunogenicity of the vaccine during storage. As with most NTD vaccines, the Na-GST-1/Alhydrogel Hookworm Vaccine was not developed by attenuation or inactivation of the pathogen (Necator americanus), so conventional methods for measuring relative potency are not relevant for this investigational product. Herein, we describe a novel relative potency testing program and report for the first time on the clinical lot of this NTD vaccine during its first 60 months of storage at 2-8°C. We also describe the development of a complementary functional assay that measures the ability of IgG from animals or humans immunized with Na-GST-1/Alhydrogel to neutralize this important hookworm enzyme. While 90% inhibition of the catalytic activity of Na-GST-1 was achieved in animals immunized with Na-GST-1/Alhydrogel, lower levels of inhibition were observed in immunized humans. Moreover, anti-Na-GST-1 antibodies from volunteers in non-hookworm endemic areas were better able to inhibit catalytic activity than anti-Na-GST-1 antibodies from volunteers resident in hookworm endemic areas. The results described herein provide the critical tools for the product development of NTD vaccines.
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Affiliation(s)
- Jill B. Brelsford
- Department of Microbiology, Immunology and Tropical Medicine, School of Medicine and Health Sciences, The George Washington University, Washington DC, United States of America
| | - Jordan L. Plieskatt
- Department of Microbiology, Immunology and Tropical Medicine, School of Medicine and Health Sciences, The George Washington University, Washington DC, United States of America
| | - Anna Yakovleva
- Department of Microbiology, Immunology and Tropical Medicine, School of Medicine and Health Sciences, The George Washington University, Washington DC, United States of America
| | - Amar Jariwala
- Department of Pathology, School of Medicine and Health Sciences, The George Washington University, Washington DC, United States of America
| | - Brian P. Keegan
- Department of Pediatrics, Section of Pediatric Tropical Medicine, Sabin Vaccine Institute and Texas Children's Hospital Center for Vaccine Development, Baylor College of Medicine, Houston, TX, United States of America
| | - Jin Peng
- Department of Microbiology, Immunology and Tropical Medicine, School of Medicine and Health Sciences, The George Washington University, Washington DC, United States of America
| | - Pengjun Xia
- Department of Microbiology, Immunology and Tropical Medicine, School of Medicine and Health Sciences, The George Washington University, Washington DC, United States of America
| | - Guangzhao Li
- Department of Microbiology, Immunology and Tropical Medicine, School of Medicine and Health Sciences, The George Washington University, Washington DC, United States of America
| | - Doreen Campbell
- Department of Microbiology, Immunology and Tropical Medicine, School of Medicine and Health Sciences, The George Washington University, Washington DC, United States of America
| | | | | | - Maria Elena Bottazzi
- Department of Pathology, School of Medicine and Health Sciences, The George Washington University, Washington DC, United States of America
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States of America
| | - Peter J. Hotez
- Department of Pathology, School of Medicine and Health Sciences, The George Washington University, Washington DC, United States of America
- National School of Tropical Medicine, Baylor College of Medicine, Houston, TX, United States of America
| | - David Diemert
- Department of Microbiology, Immunology and Tropical Medicine, School of Medicine and Health Sciences, The George Washington University, Washington DC, United States of America
| | - Jeffrey M. Bethony
- Department of Microbiology, Immunology and Tropical Medicine, School of Medicine and Health Sciences, The George Washington University, Washington DC, United States of America
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White JA, Estrada M, Flood EA, Mahmood K, Dhere R, Chen D. Development of a stable liquid formulation of live attenuated influenza vaccine. Vaccine 2016; 34:3676-83. [PMID: 27155495 PMCID: PMC4940209 DOI: 10.1016/j.vaccine.2016.04.074] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2015] [Revised: 04/08/2016] [Accepted: 04/25/2016] [Indexed: 11/02/2022]
Abstract
Vaccination is the most effective means of preventing influenza. However, the cost of producing annual seasonal influenza vaccines puts them out of reach for most developing countries. While live attenuated influenza vaccines are among the most efficacious and can be manufactured at low cost, they may require lyophilization to be stable enough for developing-country use, which adds a significant cost burden. The development of a liquid live attenuated seasonal influenza vaccine that is stable for around a year-the duration of an annual influenza season-would significantly improve not only the production output but also the use and accessibility of influenza vaccines in low-resource settings. In this study, potential stabilizing excipients were screened and optimized using the least stable influenza vaccine strain presently known, H1N1 (A/California/07/2009), as a model. The stability-conferring properties of the lead formulations were also tested with a Type B strain of influenza virus (B/Brisbane/60/2008). Stability was also evaluated with higher titers of influenza virus and exposure to agitation and freeze-thaw stresses to further confirm the stability of the lead formulations. Through this process, we identified a liquid formulation consisting of sucrose phosphate glutamate buffer with 1% arginine and 0.5% recombinant human serum albumin that provided storage stability of one year at 2-8°C for the influenza A and B strains tested.
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Affiliation(s)
| | | | | | | | - Rajeev Dhere
- Serum Institute of India Pvt Ltd, Pune, MH, India
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Kumar S, Zheng H, Mahajan B, Kozakai Y, Morin M, Locke E. Western blot assay for quantitative and qualitative antigen detection in vaccine development. CURRENT PROTOCOLS IN MICROBIOLOGY 2014; 33:18.4.1-11. [PMID: 24789597 DOI: 10.1002/9780471729259.mc1804s33] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Immunological methods for quantitative measurement, antigenic characterization, and monitoring the stability of active immunogenic component(s) are a critical need in the vaccine development process. This unit describes an enhanced chemiluminescence-based western blot for quantitative detection of Plasmodium falciparum circumsporozoite protein (PfCSP), a major malaria candidate vaccine antigen. The most salient features of this assay are its high sensitivity and reproducibility; it can reliably detect ∼5 to 10 pg PfCSP expressed on native parasites or recombinantly expressed in Escherichia coli. Although described for a specific vaccine antigen, this assay should be applicable for any antigen-antibody combination for which relevant detection reagents are available. Detailed stepwise experimental procedures and methods for data acquisition and analysis are described.
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Affiliation(s)
- Sanjai Kumar
- Laboratory of Emerging Pathogens, Division of Emerging and Transfusion Transmitted Diseases, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, Rockville, Maryland
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Fox CB, Kramer RM, Barnes V L, Dowling QM, Vedvick TS. Working together: interactions between vaccine antigens and adjuvants. THERAPEUTIC ADVANCES IN VACCINES 2014; 1:7-20. [PMID: 24757512 DOI: 10.1177/2051013613480144] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
The development of vaccines containing adjuvants has the potential to enhance antibody and cellular immune responses, broaden protective immunity against heterogeneous pathogen strains, enable antigen dose sparing, and facilitate efficacy in immunocompromised populations. Nevertheless, the structural interplay between antigen and adjuvant components is often not taken into account in the published literature. Interactions between antigen and adjuvant formulations should be well characterized to enable optimum vaccine stability and efficacy. This review focuses on the importance of characterizing antigen-adjuvant interactions by summarizing findings involving widely used adjuvant formulation platforms, such as aluminum salts, emulsions, lipid vesicles, and polymer-based particles. Emphasis is placed on the physicochemical basis of antigen-adjuvant associations and the appropriate analytical tools for their characterization, as well as discussing the effects of these interactions on vaccine potency.
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Zhu D, Huang S, McClellan H, Dai W, Syed NR, Gebregeorgis E, Rausch KM, Mullen GED, Long C, Martin LB, Narum D, Duffy P, Miller LH, Saul A. Efficient extraction of vaccines formulated in aluminum hydroxide gel by including surfactants in the extraction buffer. Vaccine 2012; 30:189-94. [PMID: 22107848 PMCID: PMC3246088 DOI: 10.1016/j.vaccine.2011.11.025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2011] [Revised: 11/03/2011] [Accepted: 11/07/2011] [Indexed: 11/21/2022]
Abstract
Efficient antigen extraction from vaccines formulated on aluminum hydroxide gels is a critical step for the evaluation of the quality of vaccines following formulation. It has been shown in our laboratory that the efficiency of antigen extraction from vaccines formulated on Alhydrogel decreased significantly with increased storage time. To increase antigen extraction efficiency, the present study determined the effect of surfactants on antigen recovery from vaccine formulations. The Plasmodium falciparum apical membrane antigen 1 (AMA1) formulated on Alhydrogel and stored at 2-8°C for 3 years was used as a model in this study. The AMA1 on Alhydrogel was extracted in the presence or absence of 30 mM sodium dodecyl sulfate (SDS) or 20mM cetylpyridinium chloride in the extraction buffer (0.60 M citrate, 0.55 M phosphate, pH 8.5) using our standard antigen extraction protocols. Extracted AMA1 antigen was analyzed by 4-20% Tris-glycine SDS-PAGE followed by silver staining or western blotting. The results showed that inclusion of SDS or cetylpyridinium chloride in extraction buffer increased the antigen recovery dramatically and can be used for efficient characterization of Alhydrogel vaccines.
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Affiliation(s)
- Daming Zhu
- Laboratory of Malaria Immunology and Vaccinology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Rockville, MD 20852, USA.
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