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Santos-Junior MN, Neves WS, Santos RS, Almeida PP, Fernandes JM, Guimarães BCDB, Barbosa MS, da Silva LSC, Gomes CP, Sampaio BA, Rezende IDS, Correia TML, Neres NSDM, Campos GB, Bastos BL, Timenetsky J, Marques LM. Heterologous Expression, Purification, and Immunomodulatory Effects of Recombinant Lipoprotein GUDIV-103 Isolated from Ureaplasma diversum. Microorganisms 2022; 10:microorganisms10051032. [PMID: 35630474 PMCID: PMC9147684 DOI: 10.3390/microorganisms10051032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 05/05/2022] [Accepted: 05/07/2022] [Indexed: 02/06/2023] Open
Abstract
Ureaplasma diversum is a bacterial pathogen that infects cattle and can cause severe inflammation of the genital and reproductive systems. Lipid-associated membrane proteins (LAMPs), including GUDIV-103, are the main virulence factors in this bacterium. In this study, we heterologously expressed recombinant GUDIV-103 (rGUDIV-103) in Escherichia coli, purified it, and evaluated its immunological reactivity and immunomodulatory effects in bovine peripheral blood mononuclear cells (PBMCs). Samples from rabbits inoculated with purified rGUDIV-103 were analysed using indirect enzyme-linked immunosorbent assay and dot blotting to confirm polyclonal antibody production and assess kinetics, respectively. The expression of this lipoprotein in field isolates was confirmed via Western blotting with anti-rGUDIV-103 serum and hydrophobic or hydrophilic proteins from 42 U. diversum strains. Moreover, the antibodies produced against the U. diversum ATCC 49783 strain recognised rGUDIV-103. The mitogenic potential of rGUDIV-103 was evaluated using a lymphoproliferation assay in 5(6)-carboxyfluorescein diacetate succinimidyl ester−labelled bovine PBMCs, where it induced lymphocyte proliferation. Quantitative polymerase chain reaction analysis revealed that the expression of interleukin-1β, toll-like receptor (TLR)-α, TLR2, TLR4, inducible nitric oxide synthase, and caspase-3−encoding genes increased more in rGUDIV-103−treated PBMCs than in untreated cells (p < 0.05). Treating PBMCs with rGUDIV-103 increased nitric oxide and hydrogen peroxide levels. The antigenic and immunogenic properties of rGUDIV-103 suggested its suitability for immunobiological application.
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Affiliation(s)
- Manoel Neres Santos-Junior
- Department of Biointeraction, Multidisciplinary Institute of Health, Federal University of Bahia, Vitória da Conquista 40170-110, Brazil; (M.N.S.-J.); (W.S.N.); (R.S.S.); (J.M.F.); (T.M.L.C.); (N.S.d.M.N.)
- Department of Biology, and Biotechnology of Microorganisms, State University of Santa Cruz (UESC), Ilhéus 45662-900, Brazil; (B.C.d.B.G.); (L.S.C.d.S.); (C.P.G.); (B.A.S.); (G.B.C.); (B.L.B.)
| | - Wanderson Souza Neves
- Department of Biointeraction, Multidisciplinary Institute of Health, Federal University of Bahia, Vitória da Conquista 40170-110, Brazil; (M.N.S.-J.); (W.S.N.); (R.S.S.); (J.M.F.); (T.M.L.C.); (N.S.d.M.N.)
| | - Ronaldo Silva Santos
- Department of Biointeraction, Multidisciplinary Institute of Health, Federal University of Bahia, Vitória da Conquista 40170-110, Brazil; (M.N.S.-J.); (W.S.N.); (R.S.S.); (J.M.F.); (T.M.L.C.); (N.S.d.M.N.)
| | - Palloma Porto Almeida
- Bioinformatics and Computational Biology Lab, Division of Experimental and Translational Research, Brazilian National Cancer Institute (INCA), Rio de Janeiro 20231-050, Brazil;
| | - Janaina Marinho Fernandes
- Department of Biointeraction, Multidisciplinary Institute of Health, Federal University of Bahia, Vitória da Conquista 40170-110, Brazil; (M.N.S.-J.); (W.S.N.); (R.S.S.); (J.M.F.); (T.M.L.C.); (N.S.d.M.N.)
| | - Bruna Carolina de Brito Guimarães
- Department of Biology, and Biotechnology of Microorganisms, State University of Santa Cruz (UESC), Ilhéus 45662-900, Brazil; (B.C.d.B.G.); (L.S.C.d.S.); (C.P.G.); (B.A.S.); (G.B.C.); (B.L.B.)
| | - Maysa Santos Barbosa
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, São Paulo 05508-000, Brazil; (M.S.B.); (I.d.S.R.); (J.T.)
| | - Lucas Santana Coelho da Silva
- Department of Biology, and Biotechnology of Microorganisms, State University of Santa Cruz (UESC), Ilhéus 45662-900, Brazil; (B.C.d.B.G.); (L.S.C.d.S.); (C.P.G.); (B.A.S.); (G.B.C.); (B.L.B.)
| | - Camila Pacheco Gomes
- Department of Biology, and Biotechnology of Microorganisms, State University of Santa Cruz (UESC), Ilhéus 45662-900, Brazil; (B.C.d.B.G.); (L.S.C.d.S.); (C.P.G.); (B.A.S.); (G.B.C.); (B.L.B.)
| | - Beatriz Almeida Sampaio
- Department of Biology, and Biotechnology of Microorganisms, State University of Santa Cruz (UESC), Ilhéus 45662-900, Brazil; (B.C.d.B.G.); (L.S.C.d.S.); (C.P.G.); (B.A.S.); (G.B.C.); (B.L.B.)
| | - Izadora de Souza Rezende
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, São Paulo 05508-000, Brazil; (M.S.B.); (I.d.S.R.); (J.T.)
| | - Thiago Macedo Lopes Correia
- Department of Biointeraction, Multidisciplinary Institute of Health, Federal University of Bahia, Vitória da Conquista 40170-110, Brazil; (M.N.S.-J.); (W.S.N.); (R.S.S.); (J.M.F.); (T.M.L.C.); (N.S.d.M.N.)
| | - Nayara Silva de Macedo Neres
- Department of Biointeraction, Multidisciplinary Institute of Health, Federal University of Bahia, Vitória da Conquista 40170-110, Brazil; (M.N.S.-J.); (W.S.N.); (R.S.S.); (J.M.F.); (T.M.L.C.); (N.S.d.M.N.)
| | - Guilherme Barreto Campos
- Department of Biology, and Biotechnology of Microorganisms, State University of Santa Cruz (UESC), Ilhéus 45662-900, Brazil; (B.C.d.B.G.); (L.S.C.d.S.); (C.P.G.); (B.A.S.); (G.B.C.); (B.L.B.)
| | - Bruno Lopes Bastos
- Department of Biology, and Biotechnology of Microorganisms, State University of Santa Cruz (UESC), Ilhéus 45662-900, Brazil; (B.C.d.B.G.); (L.S.C.d.S.); (C.P.G.); (B.A.S.); (G.B.C.); (B.L.B.)
| | - Jorge Timenetsky
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, São Paulo 05508-000, Brazil; (M.S.B.); (I.d.S.R.); (J.T.)
| | - Lucas Miranda Marques
- Department of Biointeraction, Multidisciplinary Institute of Health, Federal University of Bahia, Vitória da Conquista 40170-110, Brazil; (M.N.S.-J.); (W.S.N.); (R.S.S.); (J.M.F.); (T.M.L.C.); (N.S.d.M.N.)
- Department of Biology, and Biotechnology of Microorganisms, State University of Santa Cruz (UESC), Ilhéus 45662-900, Brazil; (B.C.d.B.G.); (L.S.C.d.S.); (C.P.G.); (B.A.S.); (G.B.C.); (B.L.B.)
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, São Paulo 05508-000, Brazil; (M.S.B.); (I.d.S.R.); (J.T.)
- Correspondence:
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Barbosa MS, Alves RPDS, Rezende IDS, Pereira SS, Campos GB, Freitas LM, Chopra-Dewasthaly R, Ferreira LCDS, Guimarães AMDS, Marques LM, Timenetsky J. Novel antigenic proteins of Mycoplasma agalactiae as potential vaccine and serodiagnostic candidates. Vet Microbiol 2020; 251:108866. [PMID: 33099078 DOI: 10.1016/j.vetmic.2020.108866] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Accepted: 09/22/2020] [Indexed: 10/23/2022]
Abstract
Contagious agalactia (CA) is a serious disease notifiable to the World Organisation for Animal Health (OIE) causing severe economic losses to sheep and goat producers worldwide. Mycoplasma agalactiae, considered as its main etiological agent, inflicts a variety of symptoms in infected animals, including keratoconjunctivitis, mastitis, arthritis, ankylosis, abortions, stillbirths and granular vulvovaginitis. Despite its significance, developing a successful vaccine remains elusive, mostly due to the lack of knowledge about M. agalactiae's pathogenicity factors and pathogenic mechanisms, including its "core" antigens. The aim of this study was to identify, characterize and express antigenic proteins of M. agalactiae as potential vaccine candidates. Predicted proteins of type strain PG2 were analyzed using bioinformatic algorithms to assess their cellular localization and to identify their linear and conformational epitopes for B cells. Out of a total of 156 predicted membrane proteins, three were shortlisted as potential antigenic surface proteins, namely [MAG_1560 (WP_011949336.1), MAG_6130 (WP_011949770.1) and P40 (WP_011949418.1)]. These proteins were expressed in recombinant Escherichia coli strains. Purified proteins were evaluated for their antigenicity using Western blot and ELISA using sera of M. agalactiae-naturally infected and non-infected sheep and goats. All 3 proteins were specifically recognized by the tested sera of M. agalactiae-infected animals. Also, specific rabbit antisera raised against each of these 3 proteins confirm their membrane localization using TritonX-114 phase partioning, Western and colony immunoblotting. In conclusion, our study successfully identified P40 (as proof of concept and validation) and two novel antigenic M. agalactiae proteins as potential candidates for developing effective CA vaccines.
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Affiliation(s)
- Maysa Santos Barbosa
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
| | - Rubens Prince Dos Santos Alves
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
| | - Izadora de Souza Rezende
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
| | - Samuel Santos Pereira
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
| | - Guilherme Barreto Campos
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil; Multidisciplinary Institute of Health, Universidade Federal da Bahia, St. Rio de Contas, 58, Vitória da Conquista, Brazil
| | - Leandro Martins Freitas
- Multidisciplinary Institute of Health, Universidade Federal da Bahia, St. Rio de Contas, 58, Vitória da Conquista, Brazil
| | - Rohini Chopra-Dewasthaly
- Institute of Microbiology, Department of Pathobiology, University of Veterinary Medicine Vienna, Veterinärplatz 1, A-1210, Vienna, Austria
| | - Luís Carlos de Souza Ferreira
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
| | - Ana Marcia de Sá Guimarães
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
| | - Lucas Miranda Marques
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil; Multidisciplinary Institute of Health, Universidade Federal da Bahia, St. Rio de Contas, 58, Vitória da Conquista, Brazil.
| | - Jorge Timenetsky
- Department of Microbiology, Institute of Biomedical Science, University of São Paulo, Av. Prof. Lineu Prestes, 1374, São Paulo, Brazil
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Andreata-Santos R, Alves RPDS, Pereira SA, Pereira LR, de Freitas CL, Pereira SS, Venceslau-Carvalho AA, Castro-Amarante MF, Favaro MTP, Mathias-Santos C, Amorim JH, Ferreira LCDS. Transcutaneous Administration of Dengue Vaccines. Viruses 2020; 12:v12050514. [PMID: 32384822 PMCID: PMC7290698 DOI: 10.3390/v12050514] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 03/26/2020] [Accepted: 04/03/2020] [Indexed: 12/28/2022] Open
Abstract
In the present study, we evaluated the immunological responses induced by dengue vaccines under experimental conditions after delivery via a transcutaneous (TC) route. Vaccines against type 2 Dengue virus particles (DENV2 New Guinea C (NGC) strain) combined with enterotoxigenic Escherichia coli (ETEC) heat-labile toxin (LT) were administered to BALB/c mice in a three-dose immunization regimen via the TC route. As a control for the parenteral administration route, other mouse groups were immunized with the same vaccine formulation via the intradermic (ID) route. Our results showed that mice vaccinated either via the TC or ID routes developed similar protective immunity, as measured after lethal challenges with the DENV2 NGC strain. Notably, the vaccine delivered through the TC route induced lower serum antibody (IgG) responses with regard to ID-immunized mice, particularly after the third dose. The protective immunity elicited in TC-immunized mice was attributed to different antigen-specific antibody properties, such as epitope specificity and IgG subclass responses, and cellular immune responses, as determined by cytokine secretion profiles. Altogether, the results of the present study demonstrate the immunogenicity and protective properties of a dengue vaccine delivered through the TC route and offer perspectives for future clinical applications.
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Affiliation(s)
- Robert Andreata-Santos
- Vaccine Development Laboratory, Microbiology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (R.A.-S.); (R.P.d.S.A.); (S.A.P.); (L.R.P.); (C.L.d.F.); (S.S.P.); (A.A.V.-C.); (M.F.C.-A.); (M.T.P.F.); (C.M.-S.)
| | - Rúbens Prince dos Santos Alves
- Vaccine Development Laboratory, Microbiology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (R.A.-S.); (R.P.d.S.A.); (S.A.P.); (L.R.P.); (C.L.d.F.); (S.S.P.); (A.A.V.-C.); (M.F.C.-A.); (M.T.P.F.); (C.M.-S.)
| | - Sara Araujo Pereira
- Vaccine Development Laboratory, Microbiology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (R.A.-S.); (R.P.d.S.A.); (S.A.P.); (L.R.P.); (C.L.d.F.); (S.S.P.); (A.A.V.-C.); (M.F.C.-A.); (M.T.P.F.); (C.M.-S.)
| | - Lennon Ramos Pereira
- Vaccine Development Laboratory, Microbiology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (R.A.-S.); (R.P.d.S.A.); (S.A.P.); (L.R.P.); (C.L.d.F.); (S.S.P.); (A.A.V.-C.); (M.F.C.-A.); (M.T.P.F.); (C.M.-S.)
| | - Carla Longo de Freitas
- Vaccine Development Laboratory, Microbiology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (R.A.-S.); (R.P.d.S.A.); (S.A.P.); (L.R.P.); (C.L.d.F.); (S.S.P.); (A.A.V.-C.); (M.F.C.-A.); (M.T.P.F.); (C.M.-S.)
| | - Samuel Santos Pereira
- Vaccine Development Laboratory, Microbiology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (R.A.-S.); (R.P.d.S.A.); (S.A.P.); (L.R.P.); (C.L.d.F.); (S.S.P.); (A.A.V.-C.); (M.F.C.-A.); (M.T.P.F.); (C.M.-S.)
| | - Alexia Adrianne Venceslau-Carvalho
- Vaccine Development Laboratory, Microbiology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (R.A.-S.); (R.P.d.S.A.); (S.A.P.); (L.R.P.); (C.L.d.F.); (S.S.P.); (A.A.V.-C.); (M.F.C.-A.); (M.T.P.F.); (C.M.-S.)
| | - Maria Fernanda Castro-Amarante
- Vaccine Development Laboratory, Microbiology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (R.A.-S.); (R.P.d.S.A.); (S.A.P.); (L.R.P.); (C.L.d.F.); (S.S.P.); (A.A.V.-C.); (M.F.C.-A.); (M.T.P.F.); (C.M.-S.)
| | - Marianna Teixeira Pinho Favaro
- Vaccine Development Laboratory, Microbiology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (R.A.-S.); (R.P.d.S.A.); (S.A.P.); (L.R.P.); (C.L.d.F.); (S.S.P.); (A.A.V.-C.); (M.F.C.-A.); (M.T.P.F.); (C.M.-S.)
| | - Camila Mathias-Santos
- Vaccine Development Laboratory, Microbiology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (R.A.-S.); (R.P.d.S.A.); (S.A.P.); (L.R.P.); (C.L.d.F.); (S.S.P.); (A.A.V.-C.); (M.F.C.-A.); (M.T.P.F.); (C.M.-S.)
| | - Jaime Henrique Amorim
- Center for Biological and Health Sciences, Federal University of Western Bahia, Bahia 47810-047, Brazil;
| | - Luís Carlos de Souza Ferreira
- Vaccine Development Laboratory, Microbiology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-000, Brazil; (R.A.-S.); (R.P.d.S.A.); (S.A.P.); (L.R.P.); (C.L.d.F.); (S.S.P.); (A.A.V.-C.); (M.F.C.-A.); (M.T.P.F.); (C.M.-S.)
- Correspondence: ; Tel.: +55-11-3091-7356
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Mirhoseini A, Amani J, Nazarian S. Review on pathogenicity mechanism of enterotoxigenic Escherichia coli and vaccines against it. Microb Pathog 2018; 117:162-169. [DOI: 10.1016/j.micpath.2018.02.032] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2017] [Revised: 01/12/2018] [Accepted: 02/15/2018] [Indexed: 12/26/2022]
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Maeda DLNF, Batista MT, Pereira LR, de Jesus Cintra M, Amorim JH, Mathias-Santos C, Pereira SA, Boscardin SB, Silva SDR, Faquim-Mauro EL, Silveira VB, Oliveira DBL, Johnston SA, Ferreira LCDS, Rodrigues JF. Adjuvant-Mediated Epitope Specificity and Enhanced Neutralizing Activity of Antibodies Targeting Dengue Virus Envelope Protein. Front Immunol 2017; 8:1175. [PMID: 28993770 PMCID: PMC5622152 DOI: 10.3389/fimmu.2017.01175] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 09/05/2017] [Indexed: 12/30/2022] Open
Abstract
The heat-labile toxins (LT) produced by enterotoxigenic Escherichia coli display adjuvant effects to coadministered antigens, leading to enhanced production of serum antibodies. Despite extensive knowledge of the adjuvant properties of LT derivatives, including in vitro-generated non-toxic mutant forms, little is known about the capacity of these adjuvants to modulate the epitope specificity of antibodies directed against antigens. This study characterizes the role of LT and its non-toxic B subunit (LTB) in the modulation of antibody responses to a coadministered antigen, the dengue virus (DENV) envelope glycoprotein domain III (EDIII), which binds to surface receptors and mediates virus entry into host cells. In contrast to non-adjuvanted or alum-adjuvanted formulations, antibodies induced in mice immunized with LT or LTB showed enhanced virus-neutralization effects that were not ascribed to a subclass shift or antigen affinity. Nonetheless, immunosignature analyses revealed that purified LT-adjuvanted EDIII-specific antibodies display distinct epitope-binding patterns with regard to antibodies raised in mice immunized with EDIII or the alum-adjuvanted vaccine. Notably, the analyses led to the identification of a specific EDIII epitope located in the EF to FG loop, which is involved in the entry of DENV into eukaryotic cells. The present results demonstrate that LT and LTB modulate the epitope specificity of antibodies generated after immunization with coadministered antigens that, in the case of EDIII, was associated with the induction of neutralizing antibody responses. These results open perspectives for the more rational development of vaccines with enhanced protective effects against DENV infections.
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Affiliation(s)
| | - Milene Tavares Batista
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.,Center for Innovation in Medicine, Biodesign Institute, Arizona State University, Tempe, AZ, United States
| | - Lennon Ramos Pereira
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Mariana de Jesus Cintra
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Jaime Henrique Amorim
- Center of Biological and Health Sciences, Federal University of Western Bahia, Bahia, Brazil
| | - Camila Mathias-Santos
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Sara Araújo Pereira
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Silvia Beatriz Boscardin
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | | | | | - Vanessa Barbosa Silveira
- Clinical and Molecular Virology Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Danielle Bruna Leal Oliveira
- Clinical and Molecular Virology Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Stephen Albert Johnston
- Center for Innovation in Medicine, Biodesign Institute, Arizona State University, Tempe, AZ, United States
| | - Luís Carlos de Souza Ferreira
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
| | - Juliana Falcão Rodrigues
- Vaccine Development Laboratory, Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil
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Gonzales-Siles L, Karlsson R, Kenny D, Karlsson A, Sjöling Å. Proteomic analysis of enterotoxigenic Escherichia coli (ETEC) in neutral and alkaline conditions. BMC Microbiol 2017; 17:11. [PMID: 28061865 PMCID: PMC5219706 DOI: 10.1186/s12866-016-0914-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2016] [Accepted: 12/13/2016] [Indexed: 12/20/2022] Open
Abstract
Background Enterotoxigenic Escherichia coli (ETEC) is a major cause of diarrhea in children and travelers to endemic areas. Secretion of the heat labile AB5 toxin (LT) is induced by alkaline conditions. In this study, we determined the surface proteome of ETEC exposed to alkaline conditions (pH 9) as compared to neutral conditions (pH 7) using a LPI Hexalane FlowCell combined with quantitative proteomics. Relative quantitation with isobaric labeling (TMT) was used to compare peptide abundance and their corresponding proteins in multiple samples at MS/MS level. For protein identification and quantification samples were analyzed using either a 1D-LCMS or a 2D-LCMS approach. Results Strong up-regulation of the ATP synthase operon encoding F1Fo ATP synthase and down-regulation of proton pumping proteins NuoF, NuoG, Ndh and WrbA were detected among proteins involved in regulating the proton and electron transport under alkaline conditions. Reduced expression of proteins involved in osmotic stress was found at alkaline conditions while the Sec-dependent transport over the inner membrane and outer membrane protein proteins such as OmpA and the β-Barrel Assembly Machinery (BAM) complex were up-regulated. Conclusions ETEC exposed to alkaline environments express a specific proteome profile characterized by up-regulation of membrane proteins and secretion of LT toxin. Alkaline microenvironments have been reported close to the intestinal epithelium and the alkaline proteome may hence represent a better view of ETEC during infection.
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Affiliation(s)
- Lucia Gonzales-Siles
- Department of Infectious Disease, Institute of Biomedicine, Sahlgrenska Academy, University of Gothenburg, SE-41346, Gothenburg, Sweden.
| | | | - Diarmuid Kenny
- Proteomics Core Facility at the University of Gothenburg, SE-43050, Gothenburg, Sweden
| | | | - Åsa Sjöling
- Department of Microbiology Tumor and Cell Biology, Karolinska Institutet, Stockholm, SE-17177, Sweden
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Gomes TAT, Elias WP, Scaletsky ICA, Guth BEC, Rodrigues JF, Piazza RMF, Ferreira LCS, Martinez MB. Diarrheagenic Escherichia coli. Braz J Microbiol 2016; 47 Suppl 1:3-30. [PMID: 27866935 PMCID: PMC5156508 DOI: 10.1016/j.bjm.2016.10.015] [Citation(s) in RCA: 252] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 10/27/2016] [Indexed: 12/22/2022] Open
Abstract
Most Escherichia coli strains live harmlessly in the intestines and rarely cause disease in healthy individuals. Nonetheless, a number of pathogenic strains can cause diarrhea or extraintestinal diseases both in healthy and immunocompromised individuals. Diarrheal illnesses are a severe public health problem and a major cause of morbidity and mortality in infants and young children, especially in developing countries. E. coli strains that cause diarrhea have evolved by acquiring, through horizontal gene transfer, a particular set of characteristics that have successfully persisted in the host. According to the group of virulence determinants acquired, specific combinations were formed determining the currently known E. coli pathotypes, which are collectively known as diarrheagenic E. coli. In this review, we have gathered information on current definitions, serotypes, lineages, virulence mechanisms, epidemiology, and diagnosis of the major diarrheagenic E. coli pathotypes.
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Affiliation(s)
- Tânia A T Gomes
- Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Microbiologia, Imunologia e Parasitologia, São Paulo, SP, Brazil.
| | - Waldir P Elias
- Instituto Butantan, Laboratório de Bacterologia, São Paulo, SP, Brazil
| | - Isabel C A Scaletsky
- Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Microbiologia, Imunologia e Parasitologia, São Paulo, SP, Brazil
| | - Beatriz E C Guth
- Universidade Federal de São Paulo, Escola Paulista de Medicina, Departamento de Microbiologia, Imunologia e Parasitologia, São Paulo, SP, Brazil
| | - Juliana F Rodrigues
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Roxane M F Piazza
- Instituto Butantan, Laboratório de Bacterologia, São Paulo, SP, Brazil
| | - Luís C S Ferreira
- Universidade de São Paulo, Instituto de Ciências Biomédicas, Departamento de Microbiologia, São Paulo, SP, Brazil
| | - Marina B Martinez
- Universidade de São Paulo, Faculdade de Ciências Farmacêuticas, Departamento de Análises Clínicas e Toxicológicas, São Paulo, SP, Brazil
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8
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Joffré E, Sjöling Å. The LT1 and LT2 variants of the enterotoxigenic Escherichia coli (ETEC) heat-labile toxin (LT) are associated with major ETEC lineages. Gut Microbes 2016; 7:75-81. [PMID: 26939855 PMCID: PMC4856455 DOI: 10.1080/19490976.2015.1127480] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The heat-labile toxin (LT) is one of the major virulence factors of enterotoxigenic Escherichia coli (ETEC). We recently described that 20 polymorphic LT variants are present in ETEC strains isolated globally. Two of the variants, LT1 and LT2, are particularly common and we found that they were associated with clonal ETEC lineages that express the colonization factors (CFs), CFA/I, CS1+CS3, CS2+CS3, and CS5+CS6. ETEC expressing these CFs are frequently found among ETEC strains isolated from cases with diarrhea. ETEC expressing the colonization factors CS1+CS3, and CS2+CS3 are found in 2 discrete clonal lineages and express the LT1 variant and heat stable toxin (STh). Although they clearly are virulent they neither produce, nor secrete, high amounts of LT toxin. On the other hand ETEC strains expressing LT, STh, CFA/I and LT, STh, CS5+CS6, carry the LT2 variant and produce and secrete significantly more LT toxin. Despite differences in toxin production, LT1 and LT2 are found in ETEC lineages that have managed to spread globally confirming that these variants are important for ETEC virulence.
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Affiliation(s)
- Enrique Joffré
- Department of Microbiology and Immunology; Sahlgrenska Academy; University of Gothenburg; Göteborg, Sweden,Institute of Molecular Biology and Biotechnology; Universidad Mayor de San Andrés; La Paz, Bolivia,Department of Microbiology; Tumor and Cell Biology; Karolinska Institutet; Stockholm, Sweden
| | - Åsa Sjöling
- Department of Microbiology; Tumor and Cell Biology; Karolinska Institutet; Stockholm, Sweden
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9
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Intradermal administration of the Type II heat-labile enterotoxins LT-IIb and LT-IIc of enterotoxigenic Escherichia coli enhances humoral and CD8+ T cell immunity to a co-administered antigen. PLoS One 2014; 9:e113978. [PMID: 25536061 PMCID: PMC4275187 DOI: 10.1371/journal.pone.0113978] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Accepted: 11/02/2014] [Indexed: 01/16/2023] Open
Abstract
Vaccinations are extremely effective at combating infectious diseases. Many conserved antigen (Ag) targets, however, are poorly immunogenic. Protein subunit vaccines frequently elicit only humoral immune responses and fail to confer protection against serious intracellular pathogens. These barriers to vaccine development are often overcome by the use of appropriate adjuvants. Heat-labile enterotoxins (HLT) produced by enterotoxigenic strains of Escherichia coli are potent adjuvants when administered by mucosal or systemic routes. The efficacy of the type II HLT, however, has not been well-defined when administered by the intradermal (ID) route. Using a murine ID immunization model, the adjuvant properties of LT-IIb and LT-IIc, two type II HLTs, were compared with those of LT-I, a prototypical type I HLT. While all three HLT adjuvants enhanced Ag-specific humoral responses to similar levels, LT-IIb and LT-IIc, in contrast to LT-I, induced a more vigorous Ag-specific CD8+ T cell response and proffered faster clearance of Listeria monocytogenes in a challenge model. Additionally, LT-IIb and LT-IIc induced distinct differences in the profiles of the Ag-specific CD8+ T cell responses. While LT-IIc stimulated a robust and rapid primary CD8+ T cell response, LT-IIb exhibited slower CD8+ T cell expansion and contraction kinetics with the formation of higher percentages of effector memory cells. In comparison to LT-I and LT-IIc, LT-IIb evoked better long-term protection after immunization. Furthermore, LT-IIb and LT-IIc enhanced the total number of dendritic cells (DC) in the draining lymph node (DLN) and expression of costimulatory molecules CD80, CD86, and CD40 on DCs. In contrast to LT-I, LT-IIb and LT-IIc induced less edema, cellular infiltrates, and general inflammation at the site of ID injection. Thus, LT-IIb and LT-IIc are attractive comprehensive ID adjuvants with unique characteristic that enhance humoral and cellular immunity to a co-administered protein Ag.
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10
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Allele variants of enterotoxigenic Escherichia coli heat-labile toxin are globally transmitted and associated with colonization factors. J Bacteriol 2014; 197:392-403. [PMID: 25404692 DOI: 10.1128/jb.02050-14] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Enterotoxigenic Escherichia coli (ETEC) is a significant cause of morbidity and mortality in the developing world. ETEC-mediated diarrhea is orchestrated by heat-labile toxin (LT) and heat-stable toxins (STp and STh), acting in concert with a repertoire of more than 25 colonization factors (CFs). LT, the major virulence factor, induces fluid secretion after delivery of a monomeric ADP-ribosylase (LTA) and its pentameric carrier B subunit (LTB). A study of ETEC isolates from humans in Brazil reported the existence of natural LT variants. In the present study, analysis of predicted amino acid sequences showed that the LT amino acid polymorphisms are associated with a geographically and temporally diverse set of 192 clinical ETEC strains and identified 12 novel LT variants. Twenty distinct LT amino acid variants were observed in the globally distributed strains, and phylogenetic analysis showed these to be associated with different CF profiles. Notably, the most prevalent LT1 allele variants were correlated with major ETEC lineages expressing CS1 + CS3 or CS2 + CS3, and the most prevalent LT2 allele variants were correlated with major ETEC lineages expressing CS5 + CS6 or CFA/I. LTB allele variants generally exhibited more-stringent amino acid sequence conservation (2 substitutions identified) than LTA allele variants (22 substitutions identified). The functional impact of LT1 and LT2 polymorphisms on virulence was investigated by measuring total-toxin production, secretion, and stability using GM1-enzyme-linked immunosorbent assays (GM1-ELISA) and in silico protein modeling. Our data show that LT2 strains produce 5-fold more toxin than LT1 strains (P < 0.001), which may suggest greater virulence potential for this genetic variant. Our data suggest that functionally distinct LT-CF variants with increased fitness have persisted during the evolution of ETEC and have spread globally.
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11
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Identification of enterotoxigenic Escherichia coli (ETEC) clades with long-term global distribution. Nat Genet 2014; 46:1321-6. [PMID: 25383970 DOI: 10.1038/ng.3145] [Citation(s) in RCA: 156] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 10/17/2014] [Indexed: 12/15/2022]
Abstract
Enterotoxigenic Escherichia coli (ETEC), a major cause of infectious diarrhea, produce heat-stable and/or heat-labile enterotoxins and at least 25 different colonization factors that target the intestinal mucosa. The genes encoding the enterotoxins and most of the colonization factors are located on plasmids found across diverse E. coli serogroups. Whole-genome sequencing of a representative collection of ETEC isolated between 1980 and 2011 identified globally distributed lineages characterized by distinct colonization factor and enterotoxin profiles. Contrary to current notions, these relatively recently emerged lineages might harbor chromosome and plasmid combinations that optimize fitness and transmissibility. These data have implications for understanding, tracking and possibly preventing ETEC disease.
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12
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Braga CJM, Rodrigues JF, Medina-Armenteros Y, Farinha-Arcieri LE, Ventura AM, Boscardin SB, Sbrogio-Almeida ME, Ferreira LCS. Parenteral Adjuvant Effects of an Enterotoxigenic Escherichia coli Natural Heat-Labile Toxin Variant. Front Immunol 2014; 4:487. [PMID: 24432018 PMCID: PMC3882871 DOI: 10.3389/fimmu.2013.00487] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2013] [Accepted: 12/10/2013] [Indexed: 12/14/2022] Open
Abstract
Native type I heat-labile toxins (LTs) produced by enterotoxigenic Escherichia coli (ETEC) strains exert strong adjuvant effects on both antibody and T cell responses to soluble and particulate antigens following co-administration via mucosal routes. However, inherent enterotoxicity and neurotoxicity (following intra-nasal delivery) had reduced the interest in the use of these toxins as mucosal adjuvants. LTs can also behave as powerful and safe adjuvants following delivery via parenteral routes, particularly for activation of cytotoxic lymphocytes. In the present study, we evaluated the adjuvant effects of a new natural LT polymorphic form (LT2), after delivery via intradermal (i.d.) and subcutaneous (s.c.) routes, with regard to both antibody and T cell responses. A recombinant HIV-1 p24 protein was employed as a model antigen for determination of antigen-specific immune responses while the reference LT (LT1), produced by the ETEC H10407 strain, and a non-toxigenic LT form (LTK63) were employed as previously characterized LT types. LT-treated mice submitted to a four dose-base immunization regimen elicited similar p24-specific serum IgG responses and CD4+ T cell activation. Nonetheless, mice immunized with LT1 or LT2 induced higher numbers of antigen-specific CD8+ T cells and in vivo cytotoxic responses compared to mice immunized with the non-toxic LT derivative. These effects were correlated with stronger activation of local dendritic cell populations. In addition, mice immunized with LT1 and LT2, but not with LTK63, via s.c. or i.d. routes developed local inflammatory reactions. Altogether, the present results confirmed that the two most prevalent natural polymorphic LT variants (LT1 or LT2) display similar and strong adjuvant effects for subunit vaccines administered via i.d. or s.c. routes.
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Affiliation(s)
- Catarina J M Braga
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo , São Paulo , Brazil ; Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo , São Paulo , Brazil
| | - Juliana F Rodrigues
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo , São Paulo , Brazil
| | - Yordanka Medina-Armenteros
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo , São Paulo , Brazil
| | - Luís E Farinha-Arcieri
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo , São Paulo , Brazil
| | - Armando M Ventura
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo , São Paulo , Brazil
| | - Silvia B Boscardin
- Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo , São Paulo , Brazil
| | | | - Luís C S Ferreira
- Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo , São Paulo , Brazil
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Mejias MP, Ghersi G, Craig PO, Panek CA, Bentancor LV, Baschkier A, Goldbaum FA, Zylberman V, Palermo MS. Immunization with a chimera consisting of the B subunit of Shiga toxin type 2 and brucella lumazine synthase confers total protection against Shiga toxins in mice. THE JOURNAL OF IMMUNOLOGY 2013; 191:2403-11. [PMID: 23918978 DOI: 10.4049/jimmunol.1300999] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The striking feature of enterohemorrhagic Escherichia coli (EHEC) infections is the production of Shiga toxins (Stx) implicated in the development of the life-threatening hemolytic uremic syndrome. Despite the magnitude of the social impact of EHEC infections, no licensed vaccine or effective therapy is available for human use. One of the biggest challenges is to develop an effective and safe immunogen to ensure nontoxicity, as well as a strong input to the immune system to induce long-lasting, high-affinity Abs with anti-Stx-neutralizing capacity. The enzyme lumazine synthase from Brucella spp. (BLS) is a highly stable dimer of pentamers and a scaffold with enormous plasticity on which to display foreign Ags. Taking into account the advantages of BLS and the potential capacity of the B subunit of Stx2 to induce Abs that prevent Stx2 toxicity by blocking its entrance into the host cells, we engineered a new immunogen by inserting the B subunit of Stx2 at the amino termini of BLS. The resulting chimera demonstrated a strong capacity to induce a long-lasting humoral immune response in mice. The chimera induced Abs with high neutralizing capacity for Stx2 and its variants. Moreover, immunized mice were completely protected against i.v. Stx2 challenge, and weaned mice receiving an oral challenge with EHEC were completely protected by the transference of immune sera. We conclude that this novel immunogen represents a promising candidate for vaccine or Ab development with preventive or therapeutic ends, for use in hemolytic uremic syndrome-endemic areas or during future outbreaks caused by pathogenic strains of Stx-producing E. coli.
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Affiliation(s)
- María P Mejias
- Laboratorio de Patogénesis e Inmunología de Procesos Infecciosos, Instituto de Medicina Experimental, Consejo Nacional de Investigaciones Cientificas y Tecnicas, Academia Nacional de Medicina, Buenos Aires C1425AUM, Argentina.
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14
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Abstract
Pathogenic Escherichia coli that colonize the small intestine primarily cause gastrointestinal illness in infants and travelers. The main categories of pathogenic E. coli that colonize the epithelial lining of the small intestine are enterotoxigenic E. coli, enteropathogenic E. coli, and enteroaggregative E. coli. These organisms accomplish their pathogenic process by a complex, coordinated multistage strategy, including nonintimate adherence mediated by various adhesins. These so called "enteroadherent E. coli" categories subsequently produce toxins or effector proteins that are either secreted to the milieu or injected to the host cell. Finally, destruction of the intestinal microvilli results from the intimate adherence or the toxic effect exerted over the epithelia, resulting in water secretion and diarrhea. In this review, we summarize the current state of knowledge regarding these enteroadherent E. coli strains and the present clinical understanding of how these organisms colonize the human intestine and cause disease.
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Chen D, Ma L, Kanalas JJ, Gao J, Pawlik J, Jimenez ME, Walter MA, Peterson JW, Gilbertson SR, Schein CH. Structure-based redesign of an edema toxin inhibitor. Bioorg Med Chem 2012; 20:368-76. [PMID: 22154558 PMCID: PMC3251925 DOI: 10.1016/j.bmc.2011.10.091] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2011] [Revised: 10/17/2011] [Accepted: 10/25/2011] [Indexed: 11/17/2022]
Abstract
Edema factor (EF) toxin of Bacillus anthracis (NIAID category A), and several other toxins from NIAID category B Biodefense target bacteria are adenylyl cyclases or adenylyl cyclase agonists that catalyze the conversion of ATP to 3',5'-cyclic adenosine monophosphate (cAMP). We previously identified compound 1 (3-[(9-oxo-9H-fluorene-1-carbonyl)-amino]-benzoic acid), that inhibits EF activity in cultured mammalian cells, and reduces diarrhea caused by enterotoxigenic Escherichia coli (ETEC) at an oral dosage of 15μg/mouse. Here, molecular docking was used to predict improvements in potency and solubility of new derivatives of compound 1 in inhibiting edema toxin (ET)-catalyzed stimulation of cyclic AMP production in murine monocyte-macrophage cells (RAW 264.7). Structure-activity relationship (SAR) analysis of the bioassay results for 22 compounds indicated positions important for activity. Several derivatives demonstrated superior pharmacological properties compared to our initial lead compound, and are promising candidates to treat anthrax infections and diarrheal diseases induced by toxin-producing bacteria.
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Affiliation(s)
- Deliang Chen
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, UTMB, Galveston, TX 77555-0857, USA
| | - Lili Ma
- Department of Chemistry, University of Houston. Houston, TX 77004, USA
| | | | - Jian Gao
- Mission Pharmacal Company, San Antonio, TX USA
| | - Jennifer Pawlik
- Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infections, UTMB, Galveston, TX 77555, USA
- Department of Microbiology and Immunology, UTMB, Galveston, TX 77555-1070, USA
| | | | | | - Johnny W. Peterson
- Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infections, UTMB, Galveston, TX 77555, USA
- Department of Microbiology and Immunology, UTMB, Galveston, TX 77555-1070, USA
| | | | - Catherine H. Schein
- Sealy Center for Structural Biology and Molecular Biophysics, Department of Biochemistry and Molecular Biology, UTMB, Galveston, TX 77555-0857, USA
- Sealy Center for Vaccine Development, Center for Biodefense and Emerging Infections, UTMB, Galveston, TX 77555, USA
- Department of Microbiology and Immunology, UTMB, Galveston, TX 77555-1070, USA
- Member, Institute for Translational Studies, UTMB
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16
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Distinctive immunomodulatory and inflammatory properties of the Escherichia coli type II heat-labile enterotoxin LT-IIa and its B pentamer following intradermal administration. CLINICAL AND VACCINE IMMUNOLOGY : CVI 2011; 18:1243-51. [PMID: 21677110 DOI: 10.1128/cvi.00012-11] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The type I and type II heat-labile enterotoxins (LT-I and LT-II) are strong mucosal adjuvants when they are coadministered with soluble antigens. Nonetheless, data on the parenteral adjuvant activities of LT-II are still limited. Particularly, no previous study has evaluated the adjuvant effects and induced inflammatory reactions of LT-II holotoxins or their B pentameric subunits after delivery via the intradermal (i.d.) route to mice. In the present report, the adjuvant and local skin inflammatory effects of LT-IIa and its B subunit pentamer (LT-IIaB(5)) were determined. When coadministered with ovalbumin (OVA), LT-IIa and, to a lesser extent, LT-IIaB(5) exhibited serum IgG adjuvant effects. In addition, LT-IIa but not LT-IIaB(5) induced T cell-specific anti-OVA responses, particularly in respect to induction of antigen-specific cytotoxic CD8(+) T cell responses. LT-IIa and LT-IIaB(5) induced differential tissue permeability and local inflammatory reactions after i.d. injection. Of particular interest was the reduced or complete lack of local reactions, such as edema and tissue induration, in mice i.d. inoculated with LT-IIa and LT-IIaB(5,) respectively, compared with mice immunized with LT-I. In conclusion, the present results show that LT-IIa and, to a lesser extent, LT-IIaB(5) exert adjuvant effects when they are delivered via the i.d. route. In addition, the low inflammatory effects of LT-IIa and LT-IIaB(5) in comparison to those of LT-I support the usefulness of LT-IIa and LT-IIaB(5) as parenterally delivered vaccine adjuvants.
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17
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Rodrigues JF, Mathias-Santos C, Sbrogio-Almeida ME, Amorim JH, Cabrera-Crespo J, Balan A, Ferreira LCS. Functional diversity of heat-labile toxins (LT) produced by enterotoxigenic Escherichia coli: differential enzymatic and immunological activities of LT1 (hLT) AND LT4 (pLT). J Biol Chem 2011; 286:5222-33. [PMID: 21135101 PMCID: PMC3037635 DOI: 10.1074/jbc.m110.173682] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2010] [Revised: 12/01/2010] [Indexed: 12/13/2022] Open
Abstract
Heat-labile toxins (LTs) have ADP-ribosylation activity and induce the secretory diarrhea caused by enterotoxigenic Escherichia coli (ETEC) strains in different mammalian hosts. LTs also act as adjuvants following delivery via mucosal, parenteral, or transcutaneous routes. Previously we have shown that LT produced by human-derived ETEC strains encompass a group of 16 polymorphic variants, including the reference toxin (LT1 or hLT) produced by the H10407 strain and one variant that is found mainly among bacterial strains isolated from pigs (LT4 or pLT). Herein, we show that LT4 (with six polymorphic sites in the A (K4R, K213E, and N238D) and B (S4T, A46E, and E102K) subunits) displays differential in vitro toxicity and in vivo adjuvant activities compared with LT1. One in vitro generated LT mutant (LTK4R), in which the lysine at position 4 of the A subunit was replaced by arginine, showed most of the LT4 features with an ∼10-fold reduction of the cytotonic effects, ADP-ribosylation activity, and accumulation of intracellular cAMP in Y1 cells. Molecular dynamic studies of the A subunit showed that the K4R replacement reduces the N-terminal region flexibility and decreases the catalytic site crevice. Noticeably, LT4 showed a stronger Th1-biased adjuvant activity with regard to LT1, particularly concerning activation of cytotoxic CD8(+) T lymphocytes when delivered via the intranasal route. Our results further emphasize the relevance of LT polymorphism among human-derived ETEC strains that may impact both the pathogenicity of the bacterial strain and the use of these toxins as potential vaccine adjuvants.
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Affiliation(s)
- Juliana F. Rodrigues
- From the Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000
| | - Camila Mathias-Santos
- From the Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000
| | | | - Jaime H. Amorim
- From the Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000
| | - Joaquim Cabrera-Crespo
- the Division of Technological Development, Butantan Institute, São Paulo, SP 05503-900, and
| | - Andrea Balan
- the National Laboratory of Biosciences, Research Centre of Energy and Material, São Paulo, SP 13084-971, Brazil
| | - Luís C. S. Ferreira
- From the Department of Microbiology, Institute of Biomedical Sciences, University of São Paulo, São Paulo, SP 05508-000
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