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Acevedo-Monroy SE, Rocha-Ramírez LM, Martínez Gómez D, Basurto-Alcántara FJ, Medina-Contreras Ó, Hernández-Chiñas U, Quiñones-Peña MA, García-Sosa DI, Ramírez-Lezama J, Rodríguez-García JA, González-Villalobos E, Castro-Luna R, Martínez-Cristóbal L, Eslava-Campos CA. Polyvalent Bacterial Lysate with Potential Use to Treatment and Control of Recurrent Urinary Tract Infections. Int J Mol Sci 2024; 25:6157. [PMID: 38892345 PMCID: PMC11173243 DOI: 10.3390/ijms25116157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2024] [Revised: 05/21/2024] [Accepted: 05/23/2024] [Indexed: 06/21/2024] Open
Abstract
Overuse of antimicrobials has greatly contributed to the increase in the emergence of multidrug-resistant bacteria, a situation that hinders the control and treatment of infectious diseases. This is the case with urinary tract infections (UTIs), which represent a substantial percentage of worldwide public health problems, thus the need to look for alternatives for their control and treatment. Previous studies have shown the usefulness of autologous bacterial lysates as an alternative for the treatment and control of UTIs. However, a limitation is the high cost of producing individual immunogens. At the same time, an important aspect of vaccines is their immunogenic amplitude, which is the reason why they must be constituted of diverse antigenic components. In the case of UTIs, the etiology of the disease is associated with different bacteria, and even Escherichia coli, the main causal agent of the disease, is made up of several antigenic variants. In this work, we present results on the study of a bacterial lysate composed of 10 serotypes of Escherichia coli and by Klebsiella pneumoniae, Klebsiella aerogenes, Enterococcus faecalis, Proteus mirabilis, Citrobacter freundii, and Staphylococcus haemolyticus. The safety of the compound was tested on cells in culture and in an animal model, and its immunogenic capacity by analysing in vitro human and murine macrophages (cell line J774 A1). The results show that the polyvalent lysate did not cause damage to the cells in culture or alterations in the animal model used. The immunostimulatory activity assay showed that it activates the secretion of TNF-α and IL-6 in human macrophages and TNF-α in murine cells. The obtained results suggest that the polyvalent lysate evaluated can be an alternative for the treatment and control of chronic urinary tract infections, which will reduce the use of antimicrobials.
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Affiliation(s)
- Salvador Eduardo Acevedo-Monroy
- Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez/Facultad de Medicina, Universidad Nacional Autónoma de México, Dr. Márquez No. 162, Col Doctores, Alcaldía Cuauhtémoc, Ciudad de México 06720, Mexico or (S.E.A.-M.); (U.H.-C.); (M.A.Q.-P.); (D.I.G.-S.); (J.A.R.-G.)
- Laboratorio de Microbiología Molecular Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Av. Universidad #3000, Colonia, C.U., Coyoacán, Ciudad de México 04510, Mexico
| | - Luz María Rocha-Ramírez
- Unidad de Investigación en Enfermedades Infecciosas, Hospital Infantil de México Federico Gómez. Secretaría de Salud, Dr. Márquez No. 162, Col Doctores, Alcaldía Cuauhtémoc, Ciudad de México 06720, Mexico;
| | - Daniel Martínez Gómez
- Departamento de Producción Agrícola y Animal, Laboratorio de Microbiología Agropecuaria, Universidad Autónoma Metropolitana Xochimilco, Calzada del Hueso 1100, Colonia Villa Quietud, Alcaldía Coyoacán, C.P., Ciudad de México 04960, Mexico;
| | - Francisco Javier Basurto-Alcántara
- Laboratorio de Vacunología y Constatación, Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Av. Universidad #3000, Colonia, C.U., Coyoacán, Ciudad de México 04510, Mexico;
| | - Óscar Medina-Contreras
- Unidad de Investigación Epidemiológica en Endocrinología y Nutrición, Hospital Infantil de México Federico Gómez, Dr. Márquez No. 162, Col. Doctores, Alcaldía Cuauhtémoc, Ciudad de México 06720, Mexico;
| | - Ulises Hernández-Chiñas
- Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez/Facultad de Medicina, Universidad Nacional Autónoma de México, Dr. Márquez No. 162, Col Doctores, Alcaldía Cuauhtémoc, Ciudad de México 06720, Mexico or (S.E.A.-M.); (U.H.-C.); (M.A.Q.-P.); (D.I.G.-S.); (J.A.R.-G.)
- Unidad Periférica de Investigación Básica y Clínica en Enfermedades Infecciosas; Departamento de Salud Pública, División de Investigación Facultad de Medicina, Universidad Nacional Autónoma de México, Dr. Márquez No. 162, Col Doctores, Alcaldía Cuauhtémoc, Ciudad de México 06720, Mexico
| | - María Alejandra Quiñones-Peña
- Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez/Facultad de Medicina, Universidad Nacional Autónoma de México, Dr. Márquez No. 162, Col Doctores, Alcaldía Cuauhtémoc, Ciudad de México 06720, Mexico or (S.E.A.-M.); (U.H.-C.); (M.A.Q.-P.); (D.I.G.-S.); (J.A.R.-G.)
- Department of Health & Biomedical Science College of Health Professions, Biomedical Science, The University of Texas Rio Grande Valley, Edinburg, TX 78539, USA
| | - Daniela Itzel García-Sosa
- Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez/Facultad de Medicina, Universidad Nacional Autónoma de México, Dr. Márquez No. 162, Col Doctores, Alcaldía Cuauhtémoc, Ciudad de México 06720, Mexico or (S.E.A.-M.); (U.H.-C.); (M.A.Q.-P.); (D.I.G.-S.); (J.A.R.-G.)
| | - José Ramírez-Lezama
- Departamento de Patología, Facultad de Medicina Veterinaria y Zootecnia, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico;
| | - José Alejandro Rodríguez-García
- Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez/Facultad de Medicina, Universidad Nacional Autónoma de México, Dr. Márquez No. 162, Col Doctores, Alcaldía Cuauhtémoc, Ciudad de México 06720, Mexico or (S.E.A.-M.); (U.H.-C.); (M.A.Q.-P.); (D.I.G.-S.); (J.A.R.-G.)
| | - Edgar González-Villalobos
- Laboratorio de Epidemiología Molecular, Departamento de Salud Pública División de Investigación Facultad de Medicina, Universidad Nacional Autónoma de México, Av. Universidad #3000, Colonia, C.U., Coyoacán, Ciudad de México 04510, Mexico;
| | - Raúl Castro-Luna
- Bioterio, Hospital Infantil de México Federico Gómez, Dr. Márquez No. 162, Col Doctores, Alcaldía Cuauhtémoc, Ciudad de México 06720, Mexico; (R.C.-L.); (L.M.-C.)
| | - Leonel Martínez-Cristóbal
- Bioterio, Hospital Infantil de México Federico Gómez, Dr. Márquez No. 162, Col Doctores, Alcaldía Cuauhtémoc, Ciudad de México 06720, Mexico; (R.C.-L.); (L.M.-C.)
| | - Carlos Alberto Eslava-Campos
- Laboratorio de Patogenicidad Bacteriana, Unidad de Hemato-Oncología e Investigación, Hospital Infantil de México Federico Gómez/Facultad de Medicina, Universidad Nacional Autónoma de México, Dr. Márquez No. 162, Col Doctores, Alcaldía Cuauhtémoc, Ciudad de México 06720, Mexico or (S.E.A.-M.); (U.H.-C.); (M.A.Q.-P.); (D.I.G.-S.); (J.A.R.-G.)
- Unidad Periférica de Investigación Básica y Clínica en Enfermedades Infecciosas; Departamento de Salud Pública, División de Investigación Facultad de Medicina, Universidad Nacional Autónoma de México, Dr. Márquez No. 162, Col Doctores, Alcaldía Cuauhtémoc, Ciudad de México 06720, Mexico
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2
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Vega-Manriquez X, Huerta-Ascencio L, Martínez-Gómez D, López-Vidal Y, Verdugo-Rodríguez A. Influence of heat-labile serum components in the presence of OmpA on the outer membrane of Salmonella gallinarum. Arch Microbiol 2015; 198:161-9. [PMID: 26597854 DOI: 10.1007/s00203-015-1174-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 11/06/2015] [Accepted: 11/12/2015] [Indexed: 11/24/2022]
Abstract
Salmonella gallinarum is the causative agent of fowl typhoid. Being a Gram-negative bacteria, its outer membrane proteins (OMP) can be regulated by different microenvironments. S. gallinarum was cultured under the following conditions: nutrient broth (NB), NB supplemented with serum from specific pathogen-free birds (NBS) and NB with serum incubated at 56 °C prior to incubation with the bacteria (NBSD); OMP were subsequently extracted. Several changes were observed in the apparent expression of OMP, mainly a decrease in an OMP with a size of 30 kDa, approximately, under the NBS condition. In contrast, the same event was not observed in NB and NBSD when using one- and two-dimensional polyacrylamide gels (SDS-PAGE). Using the OMP with a size of 30 kDa, approximately, as antigen in indirect ELISA, we were able to differentiate serum from healthy and vaccinated birds, as well as birds infected with S. gallinarum and S. enteritidis. The amino-terminal of this protein was sequenced, showing 100 % identity with OmpA of S. typhimurium. Subsequently, we designed primers to amplify the gene by PCR. The partial sequence of the amplified gene showed 100 % identity with OmpA of S. gallinarum. (1) Heat-labile serum components influence the presence of OmpA in the OM of S. gallinarum; (2) by the way of ELISA, OmpA allows to specifically differentiate healthy from diseased birds.
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Affiliation(s)
- X Vega-Manriquez
- Facultad de Agronomía y Veterinaria, Universidad Autónoma de San Luis Potosí, San Luis Potosí, SLP, Mexico
| | - L Huerta-Ascencio
- Laboratorio de Microbiología Molecular, Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootencnia, Universidad Nacional Autónoma de México, Circuito exterior S/N, Ciudad Universitaria, UNAM CU, Coyoacan México, 04510, México City, Mexico
| | - D Martínez-Gómez
- Departamento de Producción Agrícola, Universidad Autónoma Metropolitana-Unidad Xochimilco, México City, Mexico
| | - Y López-Vidal
- Programa de Inmunología Molecular Microbiana, Facultad de Medicina, Universidad Nacional Autónoma de México, México City, Mexico
| | - A Verdugo-Rodríguez
- Laboratorio de Microbiología Molecular, Departamento de Microbiología e Inmunología, Facultad de Medicina Veterinaria y Zootencnia, Universidad Nacional Autónoma de México, Circuito exterior S/N, Ciudad Universitaria, UNAM CU, Coyoacan México, 04510, México City, Mexico.
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3
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Rodríguez-Morales O, Fernández-Mora M, Hernández-Lucas I, Vázquez A, Puente JL, Calva E. Salmonella enterica serovar Typhimurium ompS1 and ompS2 mutants are attenuated for virulence in mice. Infect Immun 2006; 74:1398-402. [PMID: 16428792 PMCID: PMC1360296 DOI: 10.1128/iai.74.2.1398-1402.2006] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Salmonella enterica serovar Typhimurium mutants with mutations in the ompS1 and ompS2 genes, which code for quiescent porins, were nevertheless highly attenuated for virulence in a mouse model, indicating a role in pathogenesis. Similarly, a strain with a mutation in the gene coding for LeuO, a positive regulator of ompS2, was also attenuated.
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Affiliation(s)
- Olivia Rodríguez-Morales
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos 62210, México
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4
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Secundino I, López-Macías C, Cervantes-Barragán L, Gil-Cruz C, Ríos-Sarabia N, Pastelin-Palacios R, Angel Villasis-Keever M, Becker I, Luis Puente J, Calva E, Isibasi A. Salmonella porins induce a sustained, lifelong specific bactericidal antibody memory response. Immunology 2006; 117:59-70. [PMID: 16423041 PMCID: PMC1782194 DOI: 10.1111/j.1365-2567.2005.02263.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
We examined the ability of porins from Salmonella enterica serovar typhi to induce a long-term antibody response in BALB/c mice. These porins triggered a strong lifelong production of immunoglobulin G (IgG) antibody in the absence of exogenous adjuvant. Analysis of the IgG subclasses produced during this antibody response revealed the presence of the subclasses IgG2b, IgG1, IgG2a and weak IgG3. Despite the high homology of porins, the long-lasting anti-S. typhi porin sera did not cross-react with S. typhimurium. Notably, the antiporin sera showed a sustained lifelong bactericidal-binding activity to the wild-type S. typhi strain, whereas porin-specific antibody titres measured by enzyme-linked immunosorbent assay (ELISA) decreased with time. Because our porin preparations contained the outer membrane proteins C and F (OmpC and OmpF), we evaluated the individual contribution of each porin to the long-lasting antibody response. OmpC and OmpF induced long-lasting antibody titres, measured by ELISA, which were sustained for 300 days. In contrast, although OmpC induced sustained high bactericidal antibody titres for 300 days, postimmunization, the bactericidal antibody titre induced by OmpF was not detected at day 180. These results indicate that OmpC is the main protein responsible for the antibody-mediated memory bactericidal response induced by porins. Taken together, our results show that porins are strong immunogens that confer lifelong specific bactericidal antibody responses in the absence of added adjuvant.
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Affiliation(s)
- Ismael Secundino
- Unidad de Investigación Médica en Inmunoquímica, Hospital de Especialidades del Centro Médico Nacional (CMN) Siglo XXI, Instituto Mexicano del Seguro Social (IMSS)México
| | - Constantino López-Macías
- Unidad de Investigación Médica en Inmunoquímica, Hospital de Especialidades del Centro Médico Nacional (CMN) Siglo XXI, Instituto Mexicano del Seguro Social (IMSS)México
| | - Luisa Cervantes-Barragán
- Unidad de Investigación Médica en Inmunoquímica, Hospital de Especialidades del Centro Médico Nacional (CMN) Siglo XXI, Instituto Mexicano del Seguro Social (IMSS)México
| | - Cristina Gil-Cruz
- Unidad de Investigación Médica en Inmunoquímica, Hospital de Especialidades del Centro Médico Nacional (CMN) Siglo XXI, Instituto Mexicano del Seguro Social (IMSS)México
| | - Nora Ríos-Sarabia
- Unidad de Investigación Médica en Inmunoquímica, Hospital de Especialidades del Centro Médico Nacional (CMN) Siglo XXI, Instituto Mexicano del Seguro Social (IMSS)México
| | | | | | - Ingeborg Becker
- Departmento de Medicina Experimental, Facultad de Medicina, UNAMMéxico
| | - José Luis Puente
- Departamento de Microbiología Molecular, Instituto de Biotecnología, UNAMCuernavaca, Morelos, México
| | - Edmundo Calva
- Departamento de Microbiología Molecular, Instituto de Biotecnología, UNAMCuernavaca, Morelos, México
| | - Armando Isibasi
- Unidad de Investigación Médica en Inmunoquímica, Hospital de Especialidades del Centro Médico Nacional (CMN) Siglo XXI, Instituto Mexicano del Seguro Social (IMSS)México
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5
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Fernández-Mora M, Puente JL, Calva E. OmpR and LeuO positively regulate the Salmonella enterica serovar Typhi ompS2 porin gene. J Bacteriol 2004; 186:2909-20. [PMID: 15126450 PMCID: PMC400630 DOI: 10.1128/jb.186.10.2909-2920.2004] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2003] [Accepted: 02/06/2004] [Indexed: 11/20/2022] Open
Abstract
The Salmonella enterica serovar Typhi ompS2 gene codes for a 362-amino-acid outer membrane protein that contains motifs common to the porin superfamily. It is expressed at very low levels compared to the major OmpC and OmpF porins, as observed for S. enterica serovar Typhi OmpS1, Escherichia coli OmpN, and Klebsiella pneumoniae OmpK37 quiescent porins. A region of 316 bp, between nucleotides -413 and -97 upstream of the transcriptional start point, is involved in negative regulation, as its removal resulted in a 10-fold increase in ompS2 expression in an S. enterica serovar Typhi wild-type strain. This enhancement in expression was not observed in isogenic mutant strains, which had specific deletions of the regulatory ompB (ompR envZ) operon. Furthermore, ompS2 expression was substantially reduced in the presence of the OmpR D55A mutant, altered in the major phosphorylation site. Upon random mutagenesis, a mutant where the transposon had inserted into the upstream regulatory region of the gene coding for the LeuO regulator, showed an increased level of ompS2 expression. Augmented expression of ompS2 was also obtained upon addition of cloned leuO to the wild-type strain, but not in an ompR isogenic derivative, consistent with the notion that the transposon insertion had increased the cellular levels of LeuO and with the observed dependence on OmpR. Moreover, LeuO and OmpR bound in close proximity, but independently, to the 5' upstream regulatory region. Thus, the OmpR and LeuO regulators positively regulate ompS2.
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Affiliation(s)
- Marcos Fernández-Mora
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Cuernavaca, Morelos 62210, México
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Nsutebu EF, Ndumbe PM, Koulla S. The increase in occurrence of typhoid fever in Cameroon: overdiagnosis due to misuse of the Widal test? Trans R Soc Trop Med Hyg 2002; 96:64-7. [PMID: 11925996 DOI: 10.1016/s0035-9203(02)90243-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
Abstract
This study investigates the cause of an apparent increase in occurrence of typhoid fever in Cameroon. The reasons explored include an overdiagnosis of the illness related to poor performance of the Widal test in laboratories and interpretation by prescribers. Questionnaires were used in 1996 to evaluate the use and interpretation of the Widal test, and checklists were used to assess its laboratory performance in 2 of the 10 provinces in Cameroon. The majority of prescribers from 20 health facilities (an average of 76% of the doctors and 61% of the nurses) could detect patients who truly had positive Widal tests and needed treatment. However, an average of 48% of the doctors and 84% of the nurses would treat patients who did not require treatment based on the Widal test result. Patients may therefore be treated unnecessarily. Most (88%) of the visited laboratories performed the Widal rapid slide agglutination test as opposed to the conventional tube agglutination test. About 14% of the laboratories that performed the rapid slide agglutination test had a score above average for each criterion evaluated. Misdiagnosis of typhoid fever leads to unnecessary expenditure and exposure of patients to the side-effects of antibiotics. In addition, misdiagnosis may result in delayed diagnosis and treatment of malaria, and other acute febrile illness.
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Affiliation(s)
- Emmanuel Fru Nsutebu
- TB Research and Development Programme, Nuffield Institute for Health, University of Leeds, 71-75 Clarendon Road, Leeds LS2 9PL, UK.
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Williams KM, Bigley EC, Raybourne RB. Identification of murine B-cell and T-cell epitopes of Escherichia coli outer membrane protein F with synthetic polypeptides. Infect Immun 2000; 68:2535-45. [PMID: 10768941 PMCID: PMC97456 DOI: 10.1128/iai.68.5.2535-2545.2000] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
The major pore-forming outer membrane proteins (Omps) of gram-negative bacteria demonstrate numerous immunomodulating properties and are involved in the virulence of pathogenic strains. Because Escherichia coli OmpF is the best-characterized porin in terms of structural and functional characteristics, in vitro B-cell and T-cell responses to this porin in six different strains of mice were analyzed. Mice were immunized with purified OmpF trimers or overlapping synthetic polypeptides (20-mers) spanning the entire 340-amino-acid sequence of the OmpF monomer. T-cell proliferative responses and immunoglobulin G antibody responses to native OmpF and the peptide analogues were determined. For each strain, patterns of T-cell proliferation were similar regardless of whether native OmpF or synthetic peptides were inoculated, although all strains recognized one or more cryptic determinants. Mice exhibited several haplotype-specific responses, but genetically permissive epitopes were also identified. Four peptides (75-94, 265-284, 295-314, and 305-324) elicited strong T-cell proliferative responses from all strains of mice when mice were presensitized with native OmpF or a homologous peptide. In general, 10 or fewer peptides were recognized by sera from mice immunized with native OmpF or synthetic peptides, and most sera from peptide-immunized mice reacted poorly with the native protein. Four peptides spanning amino acids 45 to 64, 95 to 114, 115 to 134, and 275 to 294 were recognized by sera from all strains immunized with native OmpF but not by sera from peptide-immunized mice. Peptides 245-264 and 305-324 were universally recognized by sera from peptide-immunized mice, but these sera reacted weakly or were negative when tested against the native protein. Based on the pattern of cytokine secretion by proliferating T cells, immunization with native OmpF polarizes T helper cells toward development of a TH1 response. T-cell and B-cell responses have been investigated based on the assumption that differences in epitope specificity could influence protective or pathologic host reactions. Because of the high level of structural homology of OmpF to porins isolated from other enteric pathogens, the identification of T- and B-cell-stimulatory determinants of E. coli OmpF may have broader application.
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Affiliation(s)
- K M Williams
- Immunobiology Branch, Center for Food Safety and Applied Nutrition, Food and Drug Administration, Laurel, Maryland 20708, USA.
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8
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Oropeza R, Sampieri CL, Puente JL, Calva E. Negative and positive regulation of the non-osmoregulated ompS1 porin gene in Salmonella typhi: a novel regulatory mechanism that involves OmpR. Mol Microbiol 1999; 32:243-52. [PMID: 10231482 DOI: 10.1046/j.1365-2958.1999.01329.x] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The Salmonella typhi ompS1 gene codes for an outer membrane protein of the OmpC/OmpF porin family. It is expressed at very low levels, relative to the major porins. However, deletion analysis of the 5' regulatory region showed that the gradual removal of nucleotides -310 to -88, upstream from the P1 major transcriptional start-point, resulted in a stepwise increase in expression, reaching levels 10-fold above those for the ompC major porin gene. Hence, this 222 bp segment contains cis-acting regulatory elements involved in negative control. Primer extension analysis revealed the presence of three promoters: P1 activity was OmpR dependent; P2 was expressed at a lower level in the absence of OmpR; and P3 had a minor constitutive activity. OmpR bound preferentially to box II, an 18 bp F1/C1 canonical site, the removal (-88 to -66) of which resulted in a decrease in expression thus supporting its role in positive control. Expression of ompS1 was not induced by a set of stress conditions, including a shift in osmolarity, nor was the IHF regulator involved in negative control. An ompS1 homologue was found in E. coli K-12, which contains a nonsense codon and a shift in the reading frame, whereas Salmonella typhimurium contains an open reading frame in this region. Thus, S. typhi ompS1 provides novel features in OmpR regulation.
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Affiliation(s)
- R Oropeza
- Departamento de Microbiología Molecular, Instituto de Biotecnología, Universidad Nacional Autónoma de México, Av. Universidad 2001, Cuernavaca, Morelos 62210, Mexico
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9
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10
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Fernández-Mora M, Oropeza R, Puente JL, Calva E. Isolation and characterization of ompS1, a novel Salmonella typhi outer membrane protein-encoding gene. Gene 1995; 158:67-72. [PMID: 7789812 DOI: 10.1016/0378-1119(95)00171-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
We have isolated a novel outer membrane protein (OMP)-encoding gene from Salmonella typhi (St), termed ompS1, using the ompF gene of Escherichia coli (Ec) as a heterologous probe. The structural ompS1 gene codes for an OmpS1 polypeptide that consists of 373 amino acids (aa) in the mature product, with a putative 21-aa leader sequence, containing highly conserved aa residues that have been implicated in pore formation. Mature OmpS1 (41 kDa) is larger than the OmpC, OmpF and PhoE St and Ec porins. In contrast to the major porins, it is undetectable in Coomassie-stained OMP preparations; although, when ompS1 was cloned into a high-copy-number plasmid under the control of the inducible tac promoter, it was detectable along with major OMPs. The 5' regulatory region of ompS1 has five putative binding sites for OmpR, a positive transcriptional regulator. The ompS1 gene shows restriction-fragment length polymorphism (RFLP) among Salmonellae.
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Affiliation(s)
- M Fernández-Mora
- Departamento de Microbiología Molecular, Universidad Nacional Autónoma de México, Cuernavaca, Morelos
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11
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Puente JL, Juárez D, Bobadilla M, Arias CF, Calva E. The Salmonella ompC gene: structure and use as a carrier for heterologous sequences. Gene 1995; 156:1-9. [PMID: 7537703 DOI: 10.1016/0378-1119(94)00883-t] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The Salmonella typhi (St) ompC gene codes for a major outer membrane protein (OMP) that is highly expressed in both low and high osmolarity. By hybridization studies with the entire gene or with segments thereof, ompC was found to be highly conserved within 11 different Salmonella serotypes, with the exception of S. arizonae. The study included several St isolates from Mexico and Indonesia. Variation was only detected in two (e and f) of the seven regions previously found to vary between St and E. coli ompC. Chimeric OmpC proteins, carrying a rotavirus VP4 capsid protein epitope, are well recognized by a specific monoclonal antibody (mAb) against this epitope, either in OMP preparations (by enzyme-linked immunosorbent assay; ELISA) or intact cells (by ELISA and immunogold-labelling), indicating that regions c and f are oriented towards the cell surface and are probably exposed. As has been shown before for other regulated OMP, this experimental approach could be useful for the presentation of heterologous epitopes in order to gain knowledge about porin topology, for testing the effect of altered porin surface epitopes on bacterial physiology, or else, in the development of multivalent vaccines.
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Affiliation(s)
- J L Puente
- Departamento de Microbiología Molecular, Universidad Nacional Autónoma de México, Cuernavaca
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