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von Mentzer A, Svennerholm AM. Colonization factors of human and animal-specific enterotoxigenic Escherichia coli (ETEC). Trends Microbiol 2024; 32:448-464. [PMID: 38052687 DOI: 10.1016/j.tim.2023.11.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2023] [Revised: 11/01/2023] [Accepted: 11/07/2023] [Indexed: 12/07/2023]
Abstract
Colonization factors (CFs) are major virulence factors of enterotoxigenic Escherichia coli (ETEC). This pathogen is among the most common causes of bacterial diarrhea in children in low- and middle-income countries, travelers, and livestock. CFs are major candidate antigens in vaccines under development as preventive measures against ETEC infections in humans and livestock. Recent molecular studies have indicated that newly identified CFs on human ETEC are closely related to animal ETEC CFs. Increased knowledge of pathogenic mechanisms, immunogenicity, regulation, and expression of ETEC CFs, as well as the possible spread of animal ETEC to humans, may facilitate the future development of ETEC vaccines for humans and animals. Here, we present an updated review of CFs in ETEC.
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Affiliation(s)
- Astrid von Mentzer
- Department of Microbiology and Immunology, Sahlgrenska Academy, University of Gothenburg, Sweden; Wellcome Sanger Institute, Hinxton, UK.
| | - Ann-Mari Svennerholm
- Department of Microbiology and Immunology, Sahlgrenska Academy, University of Gothenburg, Sweden
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2
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Gutiérrez RL, Porter CK, Harro C, Talaat K, Riddle MS, DeNearing B, Brubaker J, Maciel M, Laird RM, Poole S, Chakraborty S, Maier N, Sack DA, Savarino SJ. Efficacy Evaluation of an Intradermally Delivered Enterotoxigenic Escherichia coli CF Antigen I Fimbrial Tip Adhesin Vaccine Coadministered with Heat-Labile Enterotoxin with LT(R192G) against Experimental Challenge with Enterotoxigenic E. coli H10407 in Healthy Adult Volunteers. Microorganisms 2024; 12:288. [PMID: 38399692 PMCID: PMC10892241 DOI: 10.3390/microorganisms12020288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2023] [Revised: 01/16/2024] [Accepted: 01/26/2024] [Indexed: 02/25/2024] Open
Abstract
BACKGROUND Enterotoxigenic E. coli (ETEC) is a principal cause of diarrhea in travelers, deployed military personnel, and children living in low to middle-income countries. ETEC expresses a variety of virulence factors including colonization factors (CF) that facilitate adherence to the intestinal mucosa. We assessed the protective efficacy of a tip-localized subunit of CF antigen I (CFA/I), CfaE, delivered intradermally with the mutant E. coli heat-labile enterotoxin, LTR192G, in a controlled human infection model (CHIM). METHODS Three cohorts of healthy adult subjects were enrolled and given three doses of 25 μg CfaE + 100 ng LTR192G vaccine intradermally at 3-week intervals. Approximately 28 days after the last vaccination, vaccinated and unvaccinated subjects were admitted as inpatients and challenged with approximately 2 × 107 cfu of CFA/I+ ETEC strain H10407 following an overnight fast. Subjects were assessed for moderate-to-severe diarrhea for 5 days post-challenge. RESULTS A total of 52 volunteers received all three vaccinations; 41 vaccinated and 43 unvaccinated subjects were challenged and assessed for moderate-to-severe diarrhea. Naïve attack rates varied from 45.5% to 64.7% across the cohorts yielding an overall efficacy estimate of 27.8% (95% confidence intervals: -7.5-51.6%). In addition to reducing moderate-severe diarrhea rates, the vaccine significantly reduced loose stool output and overall ETEC disease severity. CONCLUSIONS This is the first study to demonstrate protection against ETEC challenge after intradermal vaccination with an ETEC adhesin. Further examination of the challenge methodology is necessary to address the variability in naïve attack rate observed among the three cohorts in the present study.
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Affiliation(s)
- Ramiro L. Gutiérrez
- Naval Medical Research Command, Silver Spring, MD 20910, USA; (R.L.G.); (M.S.R.); (R.M.L.); (S.P.); (S.J.S.)
| | - Chad K. Porter
- Naval Medical Research Command, Silver Spring, MD 20910, USA; (R.L.G.); (M.S.R.); (R.M.L.); (S.P.); (S.J.S.)
| | - Clayton Harro
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21224, USA (K.T.); (B.D.); (D.A.S.)
| | - Kawsar Talaat
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21224, USA (K.T.); (B.D.); (D.A.S.)
| | - Mark S. Riddle
- Naval Medical Research Command, Silver Spring, MD 20910, USA; (R.L.G.); (M.S.R.); (R.M.L.); (S.P.); (S.J.S.)
| | - Barbara DeNearing
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21224, USA (K.T.); (B.D.); (D.A.S.)
| | - Jessica Brubaker
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21224, USA (K.T.); (B.D.); (D.A.S.)
| | - Milton Maciel
- Naval Medical Research Command, Silver Spring, MD 20910, USA; (R.L.G.); (M.S.R.); (R.M.L.); (S.P.); (S.J.S.)
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20817, USA
| | - Renee M. Laird
- Naval Medical Research Command, Silver Spring, MD 20910, USA; (R.L.G.); (M.S.R.); (R.M.L.); (S.P.); (S.J.S.)
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20817, USA
| | - Steven Poole
- Naval Medical Research Command, Silver Spring, MD 20910, USA; (R.L.G.); (M.S.R.); (R.M.L.); (S.P.); (S.J.S.)
- Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD 20817, USA
| | - Subra Chakraborty
- Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21205, USA;
| | | | - David A. Sack
- Center for Immunization Research, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21224, USA (K.T.); (B.D.); (D.A.S.)
| | - Stephen J. Savarino
- Naval Medical Research Command, Silver Spring, MD 20910, USA; (R.L.G.); (M.S.R.); (R.M.L.); (S.P.); (S.J.S.)
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Zhou S, Yu KOA, Mabrouk MT, Jahagirdar D, Huang WC, Guerra JA, He X, Ortega J, Poole ST, Hall ER, Gomez-Duarte OG, Maciel M, Lovell JF. Antibody induction in mice by liposome-displayed recombinant enterotoxigenic Escherichia coli (ETEC) colonization antigens. Biomed J 2023; 46:100588. [PMID: 36925108 PMCID: PMC10711177 DOI: 10.1016/j.bj.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 03/03/2023] [Accepted: 03/06/2023] [Indexed: 03/17/2023] Open
Abstract
BACKGROUND Enterotoxigenic Escherichia coli (ETEC) strains cause infectious diarrhea and colonize host intestine epithelia via surface-expressed colonization factors. Colonization factor antigen I (CFA/I), a prevalent ETEC colonization factor, is a vaccine target since antibodies directed to this fimbria can block ETEC adherence and prevent diarrhea. METHODS Two recombinant antigens derived from CFA/I were investigated with a vaccine adjuvant system that displays soluble antigens on the surface of immunogenic liposomes. The first antigen, CfaEB, is a chimeric fusion protein comprising the minor (CfaE) and major (CfaB) subunits of CFA/I. The second, CfaEad, is the adhesin domain of CfaE. RESULTS Owing to their His-tag, recombinant CfaEB and CfaEad, spontaneously bound upon admixture with nanoliposomes containing cobalt-porphyrin phospholipid (CoPoP), as well as a synthetic monophosphoryl lipid A (PHAD) adjuvant. Intramuscular immunization of mice with sub-microgram doses CfaEB or CfaEad admixed with CoPoP/PHAD liposomes elicited serum IgG and intestinal IgA antibodies. The smaller CfaEad antigen benefitted more from liposome display. Serum and intestine antibodies from mice immunized with liposome-displayed CfaEB or CfaEad recognized native CFA/I fimbria as evidenced by immunofluorescence and hemagglutination inhibition assays using the CFA/I-expressing H10407 ETEC strain. CONCLUSION These data show that colonization factor-derived recombinant ETEC antigens exhibit immunogenicity when delivered in immunogenic particle-based formulations.
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Affiliation(s)
- Shiqi Zhou
- Department of Biomedical Engineering, State University of New York at Buffalo, Buffalo, NY, USA
| | - Karl O A Yu
- Division of Pediatrics Infectious Diseases, Department of Pediatrics, University at Buffalo, Buffalo, NY, USA
| | - Moustafa T Mabrouk
- Department of Biomedical Engineering, State University of New York at Buffalo, Buffalo, NY, USA
| | | | - Wei-Chiao Huang
- Department of Biomedical Engineering, State University of New York at Buffalo, Buffalo, NY, USA
| | - Julio A Guerra
- Division of Pediatrics Infectious Diseases, Department of Pediatrics, University at Buffalo, Buffalo, NY, USA
| | - Xuedan He
- Department of Biomedical Engineering, State University of New York at Buffalo, Buffalo, NY, USA
| | - Joaquin Ortega
- Department of Anatomy and Cell Biology, McGill University, Montreal, Canada
| | - Steven T Poole
- Naval Medical Research Center, Silver Spring, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA
| | - Eric R Hall
- Naval Medical Research Center, Silver Spring, MD, USA
| | - Oscar G Gomez-Duarte
- Division of Pediatrics Infectious Diseases, Department of Pediatrics, University at Buffalo, Buffalo, NY, USA
| | - Milton Maciel
- Naval Medical Research Center, Silver Spring, MD, USA; Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, USA; Department of Microbiology and Immunology, Uniformed Services University Health System, Bethesda, MD, USA.
| | - Jonathan F Lovell
- Department of Biomedical Engineering, State University of New York at Buffalo, Buffalo, NY, USA.
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Svennerholm AM, Lundgren A. Developments in oral enterotoxigenic Escherichia coli vaccines. Curr Opin Immunol 2023; 84:102372. [PMID: 37523966 DOI: 10.1016/j.coi.2023.102372] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 06/11/2023] [Accepted: 07/04/2023] [Indexed: 08/02/2023]
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a leading cause of diarrhea in children in developing countries and in travelers. WHO has affirmed ETEC as a priority vaccine target, but there is no licensed ETEC vaccine available yet. We here describe recent, promising developments of different live, inactivated, and subunit ETEC candidate vaccines expressing or containing nontoxic enterotoxin and/or colonization factor antigens with a focus on oral vaccines. Many of the ETEC candidate vaccines have been tested in clinical trials for safety and immunogenicity and some of them also for protective efficacy in field trials or in challenge studies.
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Affiliation(s)
- Ann-Mari Svennerholm
- Dept. of Microbiology and Immunology, Inst. of Biomedicine, University of Gothenburg, Sweden.
| | - Anna Lundgren
- Dept. of Microbiology and Immunology, Inst. of Biomedicine, University of Gothenburg, Sweden
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5
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Liu D, Zhan Y, Wu X, Qiao H, Zhang Y, Li B. Design, preparation and characterization of octopus-like self-releasing intracellular protein transporter LEB5 based on Escherichia coli heat-labile enterotoxin. Int J Biol Macromol 2023; 237:124172. [PMID: 36966860 DOI: 10.1016/j.ijbiomac.2023.124172] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/16/2023] [Accepted: 03/21/2023] [Indexed: 04/03/2023]
Abstract
Despite the great potential of protein drugs as intracellular therapeutic agents, the unmet challenge in breaking through the cell membrane barrier and delivering them to intracellular targets remains. Therefore, developing safe and effective delivery vehicles is critical for fundamental biomedical research and clinical applications. In this study, we designed an octopus-like self-releasing intracellular protein transporter, the LEB5, based on the heat-labile enterotoxin. This carrier comprises five identical units, each of which has three main components: a linker, a self-releasing enzyme sensitivity loop, and the LTB transport domain. The LEB5 comprises five purified monomers that self-assemble to create a pentamer with ganglioside GM1 binding capacity. The fluorescent protein EGFP was used as a reporter system to identify the LEB5 features. The high-purity fusion protein ELEB monomer was produced from modified bacteria carrying pET24a(+)-eleb recombinant plasmids. EGFP protein could effectively detach from LEB5 by low dosage trypsin, according to electrophoresis analysis. The transmission electron microscopy results indicate that both LEB5 and ELEB5 pentamers exhibit a relatively regularly spherical shape, and the differential scanning calorimetry measurements further suggest that these proteins possess excellent thermal stability. Fluorescence microscopy revealed that LEB5 translocated EGFP into different cell types. Flow cytometry showed cellular differences in the transport capacity of LEB5. According to the confocal microscopy, fluorescence analysis and western blotting data, EGFP was transferred to the endoplasmic reticulum by the LEB5 carrier, detached from LEB5 by cleavage of the enzyme-sensitive loop, and released into the cytoplasm. Within the dosage range of LEB5 10-80 μg/mL, cell counting kit-8 assay revealed no significant changes in cell viability. These results demonstrated that LEB5 is a safe and effective intracellular self-releasing delivery vehicle capable of transporting and releasing protein medicines into cells.
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Affiliation(s)
- Di Liu
- College of Biological Sciences and Technology and Center for Veterinary Medicine, Taiyuan Normal University, Jinzhong 030619, Shanxi, China.
| | - Yafen Zhan
- College of Biological Sciences and Technology and Center for Veterinary Medicine, Taiyuan Normal University, Jinzhong 030619, Shanxi, China
| | - Xiaoying Wu
- College of Biological Sciences and Technology and Center for Veterinary Medicine, Taiyuan Normal University, Jinzhong 030619, Shanxi, China
| | - Hongping Qiao
- College of Biological Sciences and Technology and Center for Veterinary Medicine, Taiyuan Normal University, Jinzhong 030619, Shanxi, China
| | - Yeli Zhang
- College of Biological Sciences and Technology and Center for Veterinary Medicine, Taiyuan Normal University, Jinzhong 030619, Shanxi, China
| | - Bo Li
- College of Biological Sciences and Technology and Center for Veterinary Medicine, Taiyuan Normal University, Jinzhong 030619, Shanxi, China; School of Environmental Science and Engineering, Taiyuan University of Technology, Taiyuan 030024, Shanxi, China.
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6
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Stone AE, Rambaran S, Trinh IV, Estrada M, Jarand CW, Williams BS, Murrell AE, Huerter CM, Bai W, Palani S, Nakanishi Y, Laird RM, Poly FM, Reed WF, White JA, Norton EB. Route and antigen shape immunity to dmLT-adjuvanted vaccines to a greater extent than biochemical stress or formulation excipients. Vaccine 2023; 41:1589-1601. [PMID: 36732163 PMCID: PMC10308557 DOI: 10.1016/j.vaccine.2023.01.033] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 01/06/2023] [Accepted: 01/16/2023] [Indexed: 02/04/2023]
Abstract
A key aspect to vaccine efficacy is formulation stability. Biochemical evaluations provide information on optimal compositions or thermal stability but are routinely validated by ex vivo analysis and not efficacy in animal models. Here we assessed formulations identified to improve or reduce stability of the mucosal adjuvant dmLT being investigated in polio and enterotoxigenic E. coli (ETEC) clinical vaccines. We observed biochemical changes to dmLT protein with formulation or thermal stress, including aggregation or subunit dissociation or alternatively resistance against these changes with specific buffer compositions. However, upon injection or mucosal vaccination with ETEC fimbriae adhesin proteins or inactivated polio virus, experimental findings indicated immunization route and co-administered antigen impacted vaccine immunogenicity more so than dmLT formulation stability (or instability). These results indicate the importance of both biochemical and vaccine-derived immunity assessment in formulation optimization. In addition, these studies have implications for use of dmLT in clinical settings and for delivery in resource poor settings.
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Affiliation(s)
- Addison E Stone
- Department of Microbiology & Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Saraswatie Rambaran
- Department of Microbiology & Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Ivy V Trinh
- Department of Microbiology & Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | | | - Curtis W Jarand
- Department of Physics and Engineering Physics, Tulane University School of Medicine, New Orleans, LA, USA
| | - Blake S Williams
- Department of Microbiology & Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Amelie E Murrell
- Department of Microbiology & Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Chelsea M Huerter
- Department of Microbiology & Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | - William Bai
- Department of Microbiology & Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Surya Palani
- Department of Microbiology & Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | | | - Renee M Laird
- Henry M. Jackson Foundation for Military Medicine, Bethesda, MD, USA; Enteric Diseases Department, Naval Medical Research Center, Silver Spring, Maryland, USA
| | - Frederic M Poly
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, Maryland, USA
| | - Wayne F Reed
- Department of Physics and Engineering Physics, Tulane University School of Medicine, New Orleans, LA, USA
| | | | - Elizabeth B Norton
- Department of Microbiology & Immunology, Tulane University School of Medicine, New Orleans, LA, USA.
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7
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Estrada MR, Bzami A, Norton EB, White JA. Identifying a stable bulk dmLT adjuvant formulation at a clinically relevant concentration. Vaccine 2023; 41:1362-1367. [PMID: 36658044 PMCID: PMC9932622 DOI: 10.1016/j.vaccine.2023.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 09/19/2022] [Accepted: 01/03/2023] [Indexed: 01/19/2023]
Abstract
Double mutant heat-labile toxin (dmLT) is a novel vaccine adjuvant under development with several different vaccine candidates. Studies using existing dmLT adjuvant stocks require significant dilution to achieve a clinically relevant dose. This dilution leads to wastage of the adjuvant. This manuscript describes a limited formulation study to improve the stability of bulk dmLT at a more clinically relevant concentration (20 µg/mL) with minimal changes to the existing bulk dmLT formulation. In vitro methods were used to evaluate dmLT stability after lyophilization and short-term accelerated stability studies. The addition of the excipient polysorbate 80 (PS80) at 0.05 % to the existing dmLT formulation was identified as the lead modification that provided improved stability of the lyophilized dmLT at 20 µg/mL through 4 weeks at 40 °C.
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Affiliation(s)
| | - Anan Bzami
- PATH, 2201 Westlake Ave, Seattle, WA 98122, United States
| | - Elizabeth B. Norton
- Department of Microbiology and Immunology, Tulane University School of Medicine, 1430 Tulane Avenue, New Orleans, LA 70112, United States
| | - Jessica A. White
- PATH, 2201 Westlake Ave, Seattle, WA 98122, United States,Corresponding author.
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8
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Geurtsen J, de Been M, Weerdenburg E, Zomer A, McNally A, Poolman J. Genomics and pathotypes of the many faces of Escherichia coli. FEMS Microbiol Rev 2022; 46:6617594. [PMID: 35749579 PMCID: PMC9629502 DOI: 10.1093/femsre/fuac031] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2021] [Accepted: 06/22/2022] [Indexed: 01/09/2023] Open
Abstract
Escherichia coli is the most researched microbial organism in the world. Its varied impact on human health, consisting of commensalism, gastrointestinal disease, or extraintestinal pathologies, has generated a separation of the species into at least eleven pathotypes (also known as pathovars). These are broadly split into two groups, intestinal pathogenic E. coli (InPEC) and extraintestinal pathogenic E. coli (ExPEC). However, components of E. coli's infinite open accessory genome are horizontally transferred with substantial frequency, creating pathogenic hybrid strains that defy a clear pathotype designation. Here, we take a birds-eye view of the E. coli species, characterizing it from historical, clinical, and genetic perspectives. We examine the wide spectrum of human disease caused by E. coli, the genome content of the bacterium, and its propensity to acquire, exchange, and maintain antibiotic resistance genes and virulence traits. Our portrayal of the species also discusses elements that have shaped its overall population structure and summarizes the current state of vaccine development targeted at the most frequent E. coli pathovars. In our conclusions, we advocate streamlining efforts for clinical reporting of ExPEC, and emphasize the pathogenic potential that exists throughout the entire species.
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Affiliation(s)
- Jeroen Geurtsen
- Janssen Vaccines and Prevention B.V., 2333 Leiden, the Netherlands
| | - Mark de Been
- Janssen Vaccines and Prevention B.V., 2333 Leiden, the Netherlands
| | | | - Aldert Zomer
- Department of Infectious Diseases and Immunology, Faculty of Veterinary Medicine, Utrecht University, 3584 Utrecht, the Netherlands
| | - Alan McNally
- Institute of Microbiology and Infection, College of Medical and Dental Sciences, University of Birmingham, B15 2TT Birmingham, United Kingdom
| | - Jan Poolman
- Janssen Vaccines and Prevention B.V., 2333 Leiden, the Netherlands
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Solis-Andrade KI, Gonzalez-Ortega O, Govea-Alonso DO, Comas-Garcia M, Rosales-Mendoza S. Production and Purification of LTB-RBD: A Potential Antigen for Mucosal Vaccine Development against SARS-CoV-2. Vaccines (Basel) 2022; 10:vaccines10101759. [PMID: 36298624 PMCID: PMC9609574 DOI: 10.3390/vaccines10101759] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2022] [Revised: 09/27/2022] [Accepted: 10/17/2022] [Indexed: 11/16/2022] Open
Abstract
Most of the current SARS-CoV-2 vaccines are based on parenteral immunization targeting the S protein. Although protective, such vaccines could be optimized by inducing effective immune responses (neutralizing IgA responses) at the mucosal surfaces, allowing them to block the virus at the earliest stage of the infectious cycle. Herein a recombinant chimeric antigen called LTB-RBD is described, which comprises the B subunit of the heat-labile enterotoxin from E. coli and a segment of the RBD from SARS-CoV-2 (aa 439-504, carrying B and T cell epitopes) from the Wuhan sequence and the variant of concern (VOC)—delta. Since LTB is a mucosal adjuvant, targeting the GM1 receptor at the surface and facilitating antigen translocation to the submucosa, this candidate will help in designing mucosal vaccines (i.e., oral or intranasal formulations). LTB-RBD was produced in E. coli and purified to homogeneity by IMAC and IMAC-anionic exchange chromatography. The yields in terms of pure LTB-RBD were 1.2 mg per liter of culture for the Wuhan sequence and 3.5 mg per liter for the delta variant. The E. coli-made LTB-RBD induced seric IgG responses and IgA responses in the mouth and feces of mice when subcutaneously administered and intestinal and mouth IgA responses when administered nasally. The expression and purification protocols developed for LTB-RBD constitute a robust system to produce vaccine candidates against SARS-CoV-2 and its variants, offering a low-cost production system with no tags and with ease of adaptation to new variants. The E. coli-made LTB-RBD will be the basis for developing mucosal vaccine candidates capable of inducing sterilizing immunity against SARS-CoV-2.
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Affiliation(s)
- Karla I. Solis-Andrade
- Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 6, San Luis Potosí 78210, Mexico
- Sección de Biotecnología, Centro de Investigación en Ciencias de la Salud y Biomedicina, Universidad Autónoma de San Luis Potosí, Av. Sierra Leona 550, Lomas 2ª. Sección, San Luis Potosí 78210, Mexico
| | - Omar Gonzalez-Ortega
- Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 6, San Luis Potosí 78210, Mexico
- Sección de Biotecnología, Centro de Investigación en Ciencias de la Salud y Biomedicina, Universidad Autónoma de San Luis Potosí, Av. Sierra Leona 550, Lomas 2ª. Sección, San Luis Potosí 78210, Mexico
| | - Dania O. Govea-Alonso
- Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 6, San Luis Potosí 78210, Mexico
- Sección de Biotecnología, Centro de Investigación en Ciencias de la Salud y Biomedicina, Universidad Autónoma de San Luis Potosí, Av. Sierra Leona 550, Lomas 2ª. Sección, San Luis Potosí 78210, Mexico
| | - Mauricio Comas-Garcia
- Sección de Microscopía de Alta Resolución, Centro de Investigación en Ciencias de la Salud y Biomedicina, Universidad Autónoma de San Luis Potosí, Av. Sierra Leona 550, Lomas 2ª. Sección, San Luis Potosí 78210, Mexico
- Sección de Genómica Médica, Centro de Investigación en Ciencias de la Salud y Biomedicina, Universidad Autónoma de San Luis Potosí, Av. Sierra Leona 550, Lomas 2ª. Sección, San Luis Potosí 78210, Mexico
- Facultad de Ciencias, Universidad Autónoma de San Luis Potosí, Av. Parque Chapultepec 1570, San Luis Potosí 78210, Mexico
| | - Sergio Rosales-Mendoza
- Facultad de Ciencias Químicas, Universidad Autónoma de San Luis Potosí, Av. Dr. Manuel Nava 6, San Luis Potosí 78210, Mexico
- Sección de Biotecnología, Centro de Investigación en Ciencias de la Salud y Biomedicina, Universidad Autónoma de San Luis Potosí, Av. Sierra Leona 550, Lomas 2ª. Sección, San Luis Potosí 78210, Mexico
- Correspondence: ; Tel./Fax: +52-444-826-2440
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Asmani F, Khavari-Nejad RA, Salmanian AH, Amani J. Immunological evaluation of recombinant chimeric construct from Enterotoxigenic E. coli expressed in hairy roots. Mol Immunol 2022; 147:81-89. [DOI: 10.1016/j.molimm.2022.02.010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2021] [Revised: 01/26/2022] [Accepted: 02/09/2022] [Indexed: 01/05/2023]
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11
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Crothers JW, Ross Colgate E, Cowan KJ, Dickson DM, Walsh M, Carmolli M, Wright PF, Norton EB, Kirkpatrick BD. Intradermal fractional-dose inactivated polio vaccine (fIPV) adjuvanted with double mutant Enterotoxigenic Escherichia coli heat labile toxin (dmLT) is well-tolerated and augments a systemic immune response to all three poliovirus serotypes in a randomized placebo-controlled trial. Vaccine 2022; 40:2705-2713. [PMID: 35367069 PMCID: PMC9024222 DOI: 10.1016/j.vaccine.2022.03.056] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 02/25/2022] [Accepted: 03/22/2022] [Indexed: 11/19/2022]
Abstract
Eradication of poliomyelitis globally is constrained by fecal shedding of live polioviruses, both wild-type and vaccine-derived strains, into the environment. Although inactivated polio vaccines (IPV) effectively protect the recipient from clinical poliomyelitis, fecal shedding of live virus still occurs following infection with either wildtype or vaccine-derived strains of poliovirus. In the drive to eliminate the last cases of polio globally, improvements in both oral polio vaccines (OPV) (to prevent reversion to virulence) and injectable polio vaccines (to improve mucosal immunity and prevent viral shedding) are underway. The E. coli labile toxin with two or "double" attenuating mutations (dmLT) may boost immunologic responses to IPV, including at mucosal sites. We performed a double-blinded phase I controlled clinical trial to evaluate safety, tolerability, as well as systemic and mucosal immunogenicity of IPV adjuvanted with dmLT, given as a fractional (1/5th) dose intradermally (fIPV-dmLT). Twenty-nine volunteers with no past exposure to OPV were randomized to a single dose of fIPV-dmLT or fIPV alone. fIPV-dmLT was well tolerated, although three subjects had mild but persistent induration and hyperpigmentation at the injection site. A ≥ 4-fold rise in serotype-specific neutralizing antibody (SNA) titers to all three serotypes was seen in 84% of subjects receiving fIPV-dmLT vs. 50% of volunteers receiving IPV alone. SNA titers were higher in the dmLT-adjuvanted group, but only differences in serotype 1 were significant. Mucosal immune responses, as measured by polio serotype specific fecal IgA were minimal in both groups and differences were not seen. fIPV-dmLT may offer a benefit over IPV alone. Beyond NAB responses protecting the individual, studies demonstrating the ability of fIPV-dmLT to prevent viral shedding are necessary. Studies employing controlled human infection models, using monovalent OPV post-vaccine are ongoing. Studies specifically in children may also be necessary and additional biomarkers of mucosal immune responses in this population are needed. Clinicaltrials.gov Identifer: NCT03922061.
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Affiliation(s)
- Jessica W Crothers
- Department of Pathology and Laboratory Medicine, Vaccine Testing Center, University of Vermont Larner College of Medicine, Burlington, VT, USA.
| | - Elizabeth Ross Colgate
- Microbiology and Molecular Genetics, Vaccine Testing Center, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Kelly J Cowan
- Department of Pediatrics, Vaccine Testing Center, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Dorothy M Dickson
- Microbiology and Molecular Genetics, Vaccine Testing Center, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - MaryClaire Walsh
- Microbiology and Molecular Genetics, Vaccine Testing Center, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Marya Carmolli
- Microbiology and Molecular Genetics, Vaccine Testing Center, University of Vermont Larner College of Medicine, Burlington, VT, USA
| | - Peter F Wright
- Department of Pediatrics, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Elizabeth B Norton
- Department of Immunology and Microbiology, Tulane University, New Orleans, LA, USA
| | - Beth D Kirkpatrick
- Microbiology and Molecular Genetics, Vaccine Testing Center, University of Vermont Larner College of Medicine, Burlington, VT, USA
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12
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Lee T, Gutiérrez RL, Maciel M, Poole S, Testa KJ, Trop S, Duplessis C, Lane A, Riddle MS, Hamer M, Alcala A, Prouty M, Maier N, Erdem R, Louis Bourgeois A, Porter CK. Safety and immunogenicity of intramuscularly administered CS6 subunit vaccine with a modified heat-labile enterotoxin from enterotoxigenic Escherichia coli. Vaccine 2021; 39:5548-5556. [PMID: 34419306 PMCID: PMC8461560 DOI: 10.1016/j.vaccine.2021.08.032] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2021] [Revised: 08/05/2021] [Accepted: 08/09/2021] [Indexed: 11/25/2022]
Abstract
INTRODUCTION Enterotoxigenic Escherichia coli (ETEC) is a common cause of infectious diarrhoea and a leading cause of morbidity and mortality in children living in resource-limited settings. It is also the leading cause of travellers' diarrhoea among civilian and military travellers. Its dual importance in global public health and travel medicine highlights the need for an effective vaccine. ETEC express colonization factors (CFs) that mediate adherence to the small intestine. An epidemiologically prevalent CF is coli surface antigen 6 (CS6). We assessed the safety and immunogenicity of a CS6-targeted candidate vaccine, CssBA, co-administered intramuscularly with the double-mutant heat-labile enterotoxin, dmLT [LT(R192G/L211A)]. METHODS This was an open-label trial. Fifty subjects received three intramuscular injections (Days 1, 22 and 43) of CssBA alone (5 µg), dmLT alone (0.1 µg) or CssBA (5, 15, 45 µg) + dmLT (0.1 and 0.5 µg). Subjects were actively monitored for adverse events for 28 days following the third vaccination. Antibody responses (IgG and IgA) were characterized in the serum and from lymphocyte supernatants (ALS) to CS6 and the native ETEC heat labile enterotoxin, LT. RESULTS Across all dose cohorts, the vaccine was safe and well-tolerated with no vaccine-related severe or serious adverse events. Among vaccine-related adverse events, a majority (98%) were mild with 79% being short-lived vaccine site reactions. Robust antibody responses were induced in a dose-dependent manner with a clear dmLT adjuvant effect. Response rates in subjects receiving 45 µg CssBA and 0.5 µg dmLT ranged from 50 to 100% across assays. CONCLUSION This is the first study to demonstrate the safety and immunogenicity of CssBA and/or dmLT administered intramuscularly. Co-administration of the two components induced robust immune responses to CS6 and LT, paving the way for future studies to evaluate the efficacy of this vaccine target and development of a multivalent, subunit ETEC vaccine.
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Affiliation(s)
- Tida Lee
- Enteric Diseases Department, Naval Medical Research Center, United States
| | - Ramiro L Gutiérrez
- Enteric Diseases Department, Naval Medical Research Center, United States
| | - Milton Maciel
- Enteric Diseases Department, Naval Medical Research Center, United States; Henry M. Jackson Foundation, United States
| | - Steven Poole
- Enteric Diseases Department, Naval Medical Research Center, United States; Henry M. Jackson Foundation, United States
| | - Kayla J Testa
- Enteric Diseases Department, Naval Medical Research Center, United States; Henry M. Jackson Foundation, United States
| | - Stefanie Trop
- Enteric Diseases Department, Naval Medical Research Center, United States; Henry M. Jackson Foundation, United States
| | | | - Alison Lane
- Uniformed Services University, United States
| | | | - Melinda Hamer
- Walter Reed Army Institute of Research, United States; Uniformed Services University, United States
| | - Ashley Alcala
- Enteric Diseases Department, Naval Medical Research Center, United States; Henry M. Jackson Foundation, United States
| | - Michael Prouty
- Enteric Diseases Department, Naval Medical Research Center, United States
| | | | | | | | - Chad K Porter
- Enteric Diseases Department, Naval Medical Research Center, United States.
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13
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Iwanaga N, Chen K, Yang H, Lu S, Hoffmann JP, Wanek A, McCombs JE, Song K, Rangel-Moreno J, Norton EB, Kolls JK. Vaccine-driven lung TRM cells provide immunity against Klebsiella via fibroblast IL-17R signaling. Sci Immunol 2021; 6:eabf1198. [PMID: 34516780 DOI: 10.1126/sciimmunol.abf1198] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
[Figure: see text].
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Affiliation(s)
- Naoki Iwanaga
- Departments of Pediatrics and Medicine, Center for Translational Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Kong Chen
- Department of Medicine, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Haoran Yang
- Departments of Pediatrics and Medicine, Center for Translational Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Shiping Lu
- Departments of Pediatrics and Medicine, Center for Translational Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Joseph P Hoffmann
- Departments of Pediatrics and Medicine, Center for Translational Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Alanna Wanek
- Departments of Pediatrics and Medicine, Center for Translational Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Janet E McCombs
- Departments of Pediatrics and Medicine, Center for Translational Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Kejing Song
- Departments of Pediatrics and Medicine, Center for Translational Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | | | - Elizabeth B Norton
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA 70112, USA
| | - Jay K Kolls
- Departments of Pediatrics and Medicine, Center for Translational Research in Infection and Inflammation, Tulane University School of Medicine, New Orleans, LA 70112, USA
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14
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Khalil I, Walker R, Porter CK, Muhib F, Chilengi R, Cravioto A, Guerrant R, Svennerholm AM, Qadri F, Baqar S, Kosek M, Kang G, Lanata C, Armah G, Wierzba T, Hasso-Agopsowicz M, Giersing B, Louis Bourgeois A. Enterotoxigenic Escherichia coli (ETEC) vaccines: Priority activities to enable product development, licensure, and global access. Vaccine 2021; 39:4266-4277. [PMID: 33965254 PMCID: PMC8273896 DOI: 10.1016/j.vaccine.2021.04.018] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 04/06/2021] [Accepted: 04/09/2021] [Indexed: 02/08/2023]
Abstract
Diarrhoeal disease attributable to enterotoxigenic Escherichia coli (ETEC) causes substantial morbidity and mortality predominantly in paediatric populations in low- and middle-income countries. In addition to acute illness, there is an increasing appreciation of the long-term consequences of enteric infections, including ETEC, on childhood growth and development. Provision of potable water and sanitation and appropriate clinical care for acute illness are critical to reduce the ETEC burden. However, these interventions are not always practical and may not achieve equitable and sustainable coverage. Vaccination may be the most cost-effective and equitable means of primary prevention; however, additional data are needed to accelerate the investment and guide the decision-making process for ETEC vaccines. First, to understand and quantify the ETEC disease burden, additional data are needed on the association between ETEC infection and physical and cognitive stunting as well as delayed educational attainment. Furthermore, the role of inappropriate or inadequate antibiotic treatment of ETEC-attributable diarrhoea may contribute to the development of antimicrobial resistance (AMR) and needs further elucidation. An ETEC vaccine that mitigates acute diarrhoeal illness and minimizes the longer-term disease manifestations could have significant public health impact and be a cost-effective countermeasure. Herein we review the ETEC vaccine pipeline, led by candidates compatible with the general parameters of the Preferred Product Characteristics (PPC) recently developed by the World Health Organization. Additionally, we have developed an ETEC Vaccine Development Strategy to provide a framework to underpin priority activities for researchers, funders and vaccine manufacturers, with the goal of addressing globally unmet data needs in the areas of research, product development, and policy, as well as commercialization and delivery. The strategy also aims to guide prioritization and co-ordination of the priority activities needed to minimize the timeline to licensure and use of ETEC vaccines, especially in in low- and middle-income countries, where they are most urgently needed.
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Affiliation(s)
| | | | | | | | - Roma Chilengi
- Centre for Infectious Disease Research in Zambia, Zambia
| | | | | | | | | | - Shahida Baqar
- National Institute of Allergy and Infectious Diseases, National Institutes of Health, USA
| | | | | | | | - George Armah
- Noguchi Memorial Institute for Medical Research, Ghana
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15
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Stone AE, Scheuermann SE, Haile CN, Cuny GD, Velasquez ML, Linhuber JP, Duddupudi AL, Vigliaturo JR, Pravetoni M, Kosten TA, Kosten TR, Norton EB. Fentanyl conjugate vaccine by injected or mucosal delivery with dmLT or LTA1 adjuvants implicates IgA in protection from drug challenge. NPJ Vaccines 2021; 6:69. [PMID: 33986280 PMCID: PMC8119695 DOI: 10.1038/s41541-021-00329-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 03/22/2021] [Indexed: 12/17/2022] Open
Abstract
Fentanyl is a major contributor to the devastating increase in overdose deaths from substance use disorders (SUD). A vaccine targeting fentanyl could be a powerful immunotherapeutic. Here, we evaluated adjuvant and delivery strategies for conjugate antigen vaccination with fentanyl-based haptens. We tested adjuvants derived from the heat-labile toxin of E. coli including dmLT and LTA1 by intramuscular, sublingual or intranasal delivery. Our results show anti-fentanyl serum antibodies and antibody secreting cells in the bone-marrow after vaccination with highest levels observed with an adjuvant (alum, dmLT, or LTA1). Vaccine adjuvanted with LTA1 or dmLT elicited the highest levels of anti-fentanyl antibodies, whereas alum achieved highest levels against the carrier protein. Vaccination with sublingual dmLT or intranasal LTA1 provided the most robust blockade of fentanyl-induced analgesia and CNS penetration correlating strongly to anti-FEN IgA. In conclusion, this study demonstrates dmLT or LTA1 adjuvant as well as mucosal delivery may be attractive strategies for improving the efficacy of vaccines against SUD.
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Affiliation(s)
- Addison E Stone
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Sarah E Scheuermann
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Colin N Haile
- Department of Psychology, University of Houston, Houston, TX, USA.,Texas Institute of Measurement Evaluation and Statistics, University of Houston, Houston, TX, USA
| | - Gregory D Cuny
- Department of Pharmacological & Pharmaceutical Sciences, University of Houston, Houston, TX, USA
| | - Marcela Lopez Velasquez
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Joshua P Linhuber
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, USA
| | - Anantha L Duddupudi
- Department of Pharmacological & Pharmaceutical Sciences, University of Houston, Houston, TX, USA
| | - Jennifer R Vigliaturo
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, USA
| | - Marco Pravetoni
- Department of Pharmacology, University of Minnesota Medical School, Minneapolis, MN, USA.,Center for Immunology, University of Minnesota, Minneapolis, MN, USA
| | - Therese A Kosten
- Department of Psychology, University of Houston, Houston, TX, USA.,Texas Institute of Measurement Evaluation and Statistics, University of Houston, Houston, TX, USA
| | - Thomas R Kosten
- Department of Psychology, University of Houston, Houston, TX, USA.,Texas Institute of Measurement Evaluation and Statistics, University of Houston, Houston, TX, USA
| | - Elizabeth B Norton
- Department of Microbiology and Immunology, Tulane University School of Medicine, New Orleans, LA, USA.
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16
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Sublingual vaccination and delivery systems. J Control Release 2021; 332:553-562. [DOI: 10.1016/j.jconrel.2021.03.017] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 03/12/2021] [Accepted: 03/13/2021] [Indexed: 12/22/2022]
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17
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Evaluation of the Immunogenicity and Protective Efficacy of an Enterotoxigenic Escherichia coli CFA/I Adhesin-Heat-Labile Toxin Chimera. Infect Immun 2020; 88:IAI.00252-20. [PMID: 32839188 DOI: 10.1128/iai.00252-20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Accepted: 08/14/2020] [Indexed: 12/20/2022] Open
Abstract
Recent efforts to develop an enterotoxigenic Escherichia coli (ETEC) vaccine have focused on the antigenically conserved tip adhesins of colonization factors. We showed previously that intranasal immunization with dsc19CfaE, a soluble variant of the in cis donor strand-complemented tip adhesin of a colonization factor of the class 5 family (CFA/I) fimbria, is highly immunogenic and protects against oral challenge with CFA/I-positive (CFA/I+) ETEC strain H10407 in the Aotus nancymaae nonhuman primate. We also reported a cholera toxin (CT)-like chimera (called dsc19CfaE-CTA2/CTB) in which the CTA1 domain of CT was replaced by dsc19CfaE that was strongly immunogenic when administered intranasally or orogastrically in mice. Here, we evaluate the immunogenicity and protective efficacy (PE) of a refined and more stable chimera comprised of a pentameric B subunit of ETEC heat-labile toxin (LTB) in lieu of the CTB pentamer and a donor strand truncation (dsc14) of CfaE. The refined chimera, dsc14CfaE-sCTA2/LTB, was highly immunogenic in mice when administered intranasally or intradermally, eliciting serum and fecal antibody responses against CfaE and LTB, as well as strong hemagglutination inhibition titers, a surrogate for neutralization of intestinal adhesion mediated by CfaE. Moreover, the chimera was safe and highly immunogenic when administered intradermally to guinea pigs. In A. nancymaae, intradermal (i.d.) immunization with chimera plus single-mutant heat-labile toxin [LT(R192G)] elicited strong serum anti-CfaE and anti-LTB antibody responses and conferred significant reduction of diarrhea compared to phosphate-buffered saline (PBS) controls (PE = 84.1%; P < 0.02). These data support the further evaluation of dsc14CfaE-sCTA2/LTB as an ETEC vaccine in humans.
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18
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Preclinical optimization of an enterotoxigenic Escherichia coli adjuvanted subunit vaccine using response surface design of experiments. NPJ Vaccines 2020; 5:83. [PMID: 32983577 PMCID: PMC7486917 DOI: 10.1038/s41541-020-00228-w] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 08/10/2020] [Indexed: 12/19/2022] Open
Abstract
Enterotoxigenic E. coli (ETEC) is a leading cause of moderate-to-severe diarrhoea. ETEC colonizes the intestine through fimbrial tip adhesin colonization factors and produces heat-stable and/or heat-labile (LT) toxins, stimulating fluid and electrolyte release leading to watery diarrhoea. We reported that a vaccine containing recombinant colonization factor antigen (CfaEB) targeting fimbrial tip adhesin of the colonization factor antigen I (CFA/I) and an attenuated LT toxoid (dmLT) elicited mucosal and systemic immune responses against both targets. Additionally, the toll-like receptor 4 ligand second-generation lipid adjuvant (TLR4-SLA) induced a potent mucosal response, dependent on adjuvant formulation. However, a combination of vaccine components at their respective individual optimal doses may not achieve the optimal immune profile. We studied a subunit ETEC vaccine prototype in mice using a response surface design of experiments (DoE), consisting of 64 vaccine dose-combinations of CfaEB, dmLT and SLA in four formulations (aqueous, aluminium oxyhydroxide, squalene-in-water stable nanoemulsion [SE] or liposomes containing the saponin Quillaja saponaria-21 [LSQ]). Nine readouts focusing on antibody functionality and plasma cell response were selected to profile the immune response of parenterally administered ETEC vaccine prototype. The data were integrated in a model to identify the optimal dosage of each vaccine component and best formulation. Compared to maximal doses used in mouse models (10 µg CfaEB, 1 µg dmLT and 5 µg SLA), a reduction in the vaccine components up to 37%, 60% and 88% for CfaEB, dmLT and SLA, respectively, maintained or even maximized immune responses, with SE and LSQ the best formulations. The DoE approach can help determine the best vaccine composition with a limited number of experiments and may accelerate development of multi-antigen/component ETEC vaccines.
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19
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U-Omp19 from Brucella abortus increases dmLT immunogenicity and improves protection against Escherichia coli heat-labile toxin (LT) oral challenge. Vaccine 2020; 38:5027-5035. [PMID: 32536545 PMCID: PMC7327514 DOI: 10.1016/j.vaccine.2020.05.039] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/13/2020] [Accepted: 05/15/2020] [Indexed: 01/18/2023]
Abstract
Oral co-administration of dmLT with U-Omp19 increases dmLT immunogenicity. U-Omp19 oral co-delivery with dmLT induces anti-LT antibody responses. U-Omp19 co-administered with dmLT protects against oral challenge with LT. U-Omp19 can allow antigen dose sparing by oral route. U-Omp19 can be used as adjuvant in an oral vaccine formulation against ETEC.
Acute diarrhea disease caused by bacterial infections is a major global health problem. Enterotoxigenic Escherichia coli (ETEC) is one of the top causes of diarrhea-associated morbidity and mortality in young children and travelers to low-income countries. There are currently no licensed vaccines for ETEC. Induction of immunity at the site of entry of the bacteria is key to prevent infection. Current approaches to ETEC vaccines include a less toxic mutant form of E. coli heat-labile toxin (double-mutant heat-labile enterotoxin -dmLT-) with both antigenic and immunostimulatory properties. U-Omp19 is a protease inhibitor from Brucella spp. with immunostimulatory properties that has been used as oral adjuvant. In this work, we use U-Omp19 as adjuvant in an oral vaccine formulation against ETEC containing dmLT in outbred and inbred mice. To evaluate antigen dose sparing by U-Omp19 three different immunization protocols with three different doses of dmLT were evaluated. We demonstrated that U-Omp19 co-delivery increases anti-LT IgA in feces using a mid-dose of dmLT following a prime-boost protocol (after one or two boosts). Oral immunization with U-Omp19 induced protection against LT challenge when co-formulated with dmLT in CD-1 and BALB/c mice. Indeed, there was a significant increase in anti-LT IgG and IgA avidity after a single oral administration of dmLT plus U-Omp19 in comparison with dmLT delivered alone. Interestingly, sera from dmLT plus U-Omp19 vaccinated mice significantly neutralize LT effect on intestine inflammation in vivo compared with sera from the group immunized with dmLT alone. These results demonstrate the adjuvant capacity of U-Omp19 to increase dmLT immunogenicity by the oral route and support its use in an oral subunit vaccine formulation against ETEC.
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20
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Gutiérrez RL, Porter CK, Jarell A, Alcala A, Riddle MS, Turiansky GW. A grading system for local skin reactions developed for clinical trials of an intradermal and transcutaneous ETEC vaccine. Vaccine 2020; 38:3773-3779. [PMID: 32253098 DOI: 10.1016/j.vaccine.2020.02.079] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 02/24/2020] [Accepted: 02/26/2020] [Indexed: 11/15/2022]
Abstract
BACKGROUND Trials assessing the safety of novel vaccine candidates are essential in the evaluation and development of candidate vaccines. Immunogenicity and dose-sparing features of vaccination approaches which target skin and associated tissues have garnered increased interest; for enteric vaccines, cutaneous vaccination has been of particular interest. Cutaneous vaccine site reactions are among the most common and visible vaccine related adverse events (AEs) when skin routes are used. Regulatory guidelines governing classification of severity focus on functional impact but are insufficient to characterize a spectrum of skin reaction and allow for comparisons of routes, doses and products with similar local cutaneous AEs. OBJECTIVES Our group developed a grading scale to evaluate and compare cutaneous vaccine site reactions ahead of early-phase clinical trials of intradermal (ID) and transcutaneous immunization (TCI) with enterotoxigenic E.coli (ETEC) vaccine candidates (adhesin-based vaccine co-administered with LTR192G). We reviewed existing methods for characterizing the appearance and severity of local vaccine site reactions following TCI and ID vaccination and devised a standardized vaccine site appearance grading scale (VSAGS) for use in the clinical development of novel ETEC vaccine candidates which focused on pathophysiologic manifestation of skin findings. RESULTS Available data from published reports revealed erythematous papules and pruritus were the most common local AEs associated with TCI. Frequency of reactions varied notably across studies as did TCI vaccination methodologies and products. ID vaccination commonly results in erythema and induration at the vaccine site as well as pigmentation changes. There was no published methodology to characterize the spectrum of dermatologic findings. CONCLUSION ID and TCI vaccination are associated with a largely predictable range of cutaneous AEs. A grading scale focused on the appearance of cutaneous changes was useful in comparing cutaneous AEs. A standardized grading scale will facilitate documentation and comparison of cutaneous AEs.
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Affiliation(s)
- Ramiro L Gutiérrez
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States.
| | - Chad K Porter
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States.
| | - Abel Jarell
- Dermatology Department, Walter Reed National Military Medical Center, Bethesda, MD, United States
| | - Ashley Alcala
- Enteric Diseases Department, Naval Medical Research Center, Silver Spring, MD, United States
| | - Mark S Riddle
- Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - George W Turiansky
- Uniformed Services University of the Health Sciences, Bethesda, MD, United States.
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21
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LTA1 and dmLT enterotoxin-based proteins activate antigen-presenting cells independent of PKA and despite distinct cell entry mechanisms. PLoS One 2020; 15:e0227047. [PMID: 31929548 PMCID: PMC6957164 DOI: 10.1371/journal.pone.0227047] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 12/11/2019] [Indexed: 01/19/2023] Open
Abstract
Enterotoxin-based proteins are powerful manipulators of mucosal immunity. The A1 domain of heat-labile enterotoxin from E. coli, or LTA1, is a newer adjuvant from this family under investigation for intranasal vaccines. Although LTA1 has been examined in mouse vaccination studies, its ability to directly stimulate immune cells compared to related adjuvant proteins has not been well explored. Here, we perform the first rigorous examination of LTA1’s effect on antigen presenting cells (APC) using a human monocyte cell line THP-1. To better understand LTA1’s stimulatory effects, we compared it to dmLT, or LT-R192G/L211A, a related AB5 adjuvant in clinical trials for oral or parenteral vaccines. LTA1 and dmLT both activated APCs to upregulate MHC-II (HLA-DR), CD86, cytokine secretion (e.g., IL-1β) and inflammasome activation. The effect of LTA1 on surface marker changes (e.g., MHC-II) was highly dose-dependent whereas dmLT exhibited high MHC-II expression regardless of dose. In contrast, cytokine secretion profiles were similar and dose-dependent after both LTA1 and dmLT treatment. Cellular activation by LTA1 was independent of ganglioside binding, as pre-treatment with purified GM1 blocked the effect of dmLT but not LTA1. Unexpectedly, while activation of the inflammasome and cytokine secretion by LTA1 or dmLT was blocked by the protein kinase A inhibitor H89 (similar to previous reports), these responses were not inhibited by a more specific PKA peptide inhibitor or antagonist; thus Indicating that a novel and unknown mechanism is responsible for inflammasome activation and cytokine secretion by LT proteins. Lastly, LTA1 stimulated a similar cytokine profile in primary human monocytes as it did in THP1 cells, including IL-1β, IL-6, IL-8, MIP-1α, MIP-1β, and TNFα. Thus, we report that LTA1 protein programs a dendritic cell-like phenotype in APCs similar to dmLT in a mechanism that is independent of PKA activation and GM1 binding and entry.
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Evaluation of the reactogenicity, adjuvanticity and antigenicity of LT(R192G) and LT(R192G/L211A) by intradermal immunization in mice. PLoS One 2019; 14:e0224073. [PMID: 31682624 PMCID: PMC6827915 DOI: 10.1371/journal.pone.0224073] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Accepted: 10/04/2019] [Indexed: 02/07/2023] Open
Abstract
The development of an effective subunit vaccine is frequently complicated by the difficulty of eliciting protective immune responses, often requiring the co-administration of an adjuvant. Heat-labile toxin (LT), an enterotoxin expressed by enterotoxigenic E. coli (ETEC) with an AB5 structure similar to cholera toxin, is a strong adjuvant. While the mucosa represents the natural route of exposure to LT and related toxins, the clinical utility of LT and similar adjuvants given by mucosal routes has been limited by toxicity, as well as the association between intranasal delivery of LT and Bell's palsy. Single and double amino acid mutants of LT, LT(R192G)/mLT and LT(R192G/L211A)/dmLT respectively, have been proposed as alternatives to reduce the toxicity associated with the holotoxin. In the present study, we compared mLT and dmLT given via a non-mucosal route (i.e. intradermally) to investigate their adjuvanticity when co-administrated with an enterotoxigenic E. coli vaccine candidate, CfaEB. Antigenicity (i.e. ability to elicit response against LT) and reactogenicity at the injection site were also evaluated. BALB/c mice were immunized by the intradermal route with CfaEB plus increasing doses of either mLT or dmLT (0.01 to 2.5 μg). Both adjuvants induced dose-dependent skin reactogenicity, with dmLT being less reactogenic than mLT. Both adjuvants significantly boosted the anti-CfaE IgG and functional hemagglutination inhibiting (HAI) antibody responses, compared to the antigen alone. In addition to inducing anti-LT responses, even at the lowest dose tested (0.01 μg), the adjuvants also prompted in vitro cytokine responses (IFN-γ, IL-4, IL-5, IL-10 and IL-17) that followed different patterns, depending on the protein used for stimulation (CfaE or LTB) and/or the dose used for immunization. The two LT mutants evaluated here, mLT and dmLT, are potent adjuvants for intradermal immunization and should be further investigated for the intradermal delivery of subunit ETEC vaccines.
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