Lienlaf M, Morales JP, Díaz MI, Díaz R, Bruce E, Siegel F, León G, Harris PR, Venegas A. Helicobacter pylori HopE and HopV porins present scarce expression among clinical isolates. World J Gastroenterol 2010; 16(3): 320-329 [PMID: 20082477 DOI: 10.3748/wjg.v16.i3.320]
Corresponding Author of This Article
Dr. Alejandro Venegas, Microbial Pathogenesis and Vaccine Biotechnology Laboratory, Department of Molecular Genetics and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 651-3492, Chile. avenegas@bio.puc.cl
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World J Gastroenterol. Jan 21, 2010; 16(3): 320-329 Published online Jan 21, 2010. doi: 10.3748/wjg.v16.i3.320
Helicobacter pylori HopE and HopV porins present scarce expression among clinical isolates
Maritza Lienlaf, Juan Pablo Morales, María Inés Díaz, Rodrigo Díaz, Elsa Bruce, Freddy Siegel, Gloria León, Paul R Harris, Alejandro Venegas
Maritza Lienlaf, Juan Pablo Morales, María Inés Díaz, Rodrigo Díaz, Elsa Bruce, Alejandro Venegas, Microbial Pathogenesis and Vaccine Biotechnology Laboratory, Department of Molecular Genetics and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 651-3492, Chile
Freddy Siegel, Gastroenterology Unit, Faculty of Medicine, Universidad Austral de Chile, Independencia 641, Valdivia 511-0566, Chile
Gloria León, Institute of Biochemistry, Faculty of Sciences, Universidad Austral de Chile, Independencia 641, Valdivia 511-0566, Chile
Paul R Harris, Department of Pediatrics, School of Medicine, Pontificia Universidad Católica de Chile, Lira 85, Santiago 833-0074, Chile
Author contributions: Lienlaf M and Morales JP performed most of the cloning and immunoblotting experiments; Díaz MI was in charge of strains stock and growth; Díaz R and Bruce E collected biopsies and isolated strains; Harris PR, Siegel F and León G provided the collection of human material and were involved in editing the manuscript; Venegas A designed the study, provided financial support for this work and wrote the manuscript.
Supported by Grants FONDECYT #1030894 and 1085232 and FONDEF DO2I-1067 from CONICYT, Chile
Correspondence to: Dr. Alejandro Venegas, Microbial Pathogenesis and Vaccine Biotechnology Laboratory, Department of Molecular Genetics and Microbiology, Faculty of Biological Sciences, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 651-3492, Chile. avenegas@bio.puc.cl
Telephone: +56-2-6862661 Fax: +56-2-2225515
Received: September 15, 2009 Revised: November 11, 2009 Accepted: November 18, 2009 Published online: January 21, 2010
Abstract
AIM: To evaluate how widely Helicobacter pylori (H. pylori) HopE and HopV porins are expressed among Chilean isolates and how seroprevalent they are among infected patients in Chile.
METHODS: H. pylori hopE and hopV genes derived from strain CHCTX-1 were cloned by polymerase chain reaction (PCR), sequenced and expressed in Escherichia coli AD494 (DE3). Gel-purified porins were used to prepare polyclonal antibodies. The presence of both genes was tested by PCR in a collection of H. pylori clinical isolates and their expression was detected in lysates by immunoblotting. Immune responses against HopE, HopV and other H. pylori antigens in sera from infected and non-infected patients were tested by Western blotting using these sera as first antibody on recombinant H. pylori antigens.
RESULTS: PCR and Western blotting assays revealed that 60 and 82 out of 130 Chilean isolates carried hopE and hopV genes, respectively, but only 16 and 9, respectively, expressed these porins. IgG serum immunoreactivity evaluation of 69 H. pylori-infected patients revealed that HopE and HopV were infrequently recognized (8.7% and 10.1% respectively) compared to H. pylori VacA (68.1%) and CagA (59.5%) antigens. Similar values were detected for IgA serum immunoreactivity against HopE (11.6%) and HopV (10.5%) although lower values for VacA (42%) and CagA (17.4%) were obtained when compared to the IgG response.
CONCLUSION: A scarce expression of HopE and HopV among Chilean isolates was found, in agreement with the infrequent seroconversion against these antigens when tested in infected Chilean patients.
