Immunization of mice with chimeric antigens displaying selected epitopes confers protection against intestinal colonization and renal damage caused by Shiga toxin-producing<i>Escherichia coli</i>

Montero, David A.; Canto, Felipe Del; Salazar, Juan Carlos; Céspedes, Sandra; Cádiz, Leandro; Arenas-Salinas, Mauricio; Reyes, José Luis; Oñate, Ángel; Vidal, Roberto

doi:10.1101/783829

Cited by 3 publications

(3 citation statements)

References 87 publications

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“…LAA presence is associated with severe human disease and although the mechanisms used by LEE-negative STEC strains to colonize the human intestine are not clear yet [17]. Recently, the role of LAA in intestinal colonization was demonstrated in a murine model of STEC infection, suggesting that LAA may be also involved in the adherence of STEC to the human intestine [18,19]. Moreover, the association of LAA with stx1a, stx2a, stx2d and cdtB toxin genes that cause severe disease has been demonstrated [18].…”

Section: Introductionmentioning

confidence: 99%

Distribution of Locus of Adhesion and Autoaggregation and hes Gene in STEC Strains from Countries of Latin America

et al. 2020

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Shiga toxin-producing Escherichia coli (STEC) are zoonotic food pathogens associated with foodborne diarrheal illness, hemorrhagic colitis, and complications such as hemolytic uremic syndrome (HUS). The ability to adhere to epithelial cells is an important virulence trait, and pathogenicity islands (PAIs) play an important role on it. Some STEC carrying a PAI named locus of enterocyte effacement (LEE-positive) have been frequently associated to HUS; however, STEC that do not carry LEE (LEE-negative) have also been associated with this outcome. The burden of disease caused by LEE-negative STEC has increased recently in several countries like Argentina, Chile, and Paraguay. A new PAI -the Locus of Adhesion and Autoagregation (LAA)-has been associated to severe disease in humans. In this study, we aimed to analyze the distribution of LAA and its possible predictor, the gene hes, in LEE-negative STEC strains isolated from Chile and Paraguay from different sources. The presence of the different LAA modules and hes were detected by PCR. LAA was found in 41.6% and 41.0% of strains isolated from Chile and Paraguay, respectively. Strains were isolated from diverse origins and belonged to several serogroups including O91, O103, and O113. The hes gene was detected in 50% of the isolates from Paraguay and Chile. Therefore, the detection of LAA and hes in STEC could complement current genetic evaluation schemes, allowing to classify LEE negative STEC strains as LAA-positive or LAA-negative STEC strains.

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Section: Introductionmentioning

confidence: 99%

Distribution of Locus of Adhesion and Autoaggregation and hes Gene in STEC Strains from Countries of Latin America

et al. 2020

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“…6B). Some studies revealed that IgG in the murine intestine leads to the elimination of the Shiga toxin-producing Escherichia coli , virulent Citrobacter rodentium , and rotavirus 27, 42, 43 . The vaccines against H. pylori were also vaccinated by systemic immune routes such as intramuscular immunization 44, 45 .…”

Section: Discussionmentioning

confidence: 99%

Embedding of exogenous B cell epitopes on the surface of UreB structure generates a broadly reactive antibody response againstHelicobacter pylori

Ma¹,

Wang²,

Ji³

et al. 2021

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Since Helicobacter pylori (H. pylori) resistance to antibiotic regimens is increased, vaccination is becoming an increasingly important alternative therapy to control H. pylori infection. UreB, FlaA, AlpB, SabA, and HpaA proteins of H. pylori were previously proved to be used as candidate vaccine antigens. Here, we developed an engineered antigen based on a recombinant chimeric protein containing a structural scaffold from UreB and B cell epitopes from FlaA, AlpB, SabA, and HpaA. The multi-epitope chimeric antigen, named MECU, could generate a broadly reactive antibody response including antigen-specific antibodies and neutralizing antibodies against H. pylori urease and adhesins. Moreover, therapeutic immunization with MECU could reduce H. pylori colonization in the stomach and protect the stomach in BALB/c mice. This study not only provides a promising immunotherapy to control H. pylori infection, but also offers a reference for antigen engineering against other pathogens.

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“…Thus, the OmpT protein participates in different mechanisms of pathogenicity in STEC and therefore is a promising target for vaccine development [ 62 ]. In fact, a recently developed vaccine candidate against STEC includes epitopes and antigenic domains of this protein [ 63 ]. Notably, this vaccine candidate confers protection on mice against the intestinal colonization and renal damage caused by STEC.…”

Section: Discussionmentioning

confidence: 99%

Deciphering Additional Roles for the EF-Tu, l-Asparaginase II and OmpT Proteins of Shiga Toxin-Producing Escherichia coli

et al. 2020

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Shiga toxin-producing Escherichia coli (STEC) causes outbreaks and sporadic cases of gastroenteritis. STEC O157:H7 is the most clinically relevant serotype in the world. The major virulence determinants of STEC O157:H7 are the Shiga toxins and the locus of enterocyte effacement. However, several accessory virulence factors, mainly outer membrane proteins (OMPs) that interact with the host cells may contribute to the virulence of this pathogen. Previously, the elongation factor thermo unstable (EF-Tu), l-asparaginase II and OmpT proteins were identified as antigens in OMP extracts of STEC. The known subcellular location of EF-Tu and l-asparaginase II are the cytoplasm and periplasm, respectively. Therefore, we investigate whether these two proteins may localize on the surface of STEC and, if so, what roles they have at this site. On the other hand, the OmpT protein, a well characterized protease, has been described as participating in the adhesion of extraintestinal pathogenic E. coli strains. Thus, we investigate whether OmpT has this role in STEC. Our results show that the EF-Tu and l-asparaginase II are secreted by O157:H7 and may also localize on the surface of this bacterium. EF-Tu was identified in outer membrane vesicles (OMVs), suggesting it as a possible export mechanism for this protein. Notably, we found that l-asparaginase II secreted by O157:H7 inhibits T-lymphocyte proliferation, but the role of EF-Tu at the surface of this bacterium remains to be elucidated. In the case of OmpT, we show its participation in the adhesion of O157:H7 to human epithelial cells. Thus, this study extends the knowledge of the pathogenic mechanisms of STEC.

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Immunization of mice with chimeric antigens displaying selected epitopes confers protection against intestinal colonization and renal damage caused by Shiga toxin-producingEscherichia coli

Cited by 3 publications

References 87 publications

Distribution of Locus of Adhesion and Autoaggregation and hes Gene in STEC Strains from Countries of Latin America

Distribution of Locus of Adhesion and Autoaggregation and hes Gene in STEC Strains from Countries of Latin America

Embedding of exogenous B cell epitopes on the surface of UreB structure generates a broadly reactive antibody response againstHelicobacter pylori

Deciphering Additional Roles for the EF-Tu, l-Asparaginase II and OmpT Proteins of Shiga Toxin-Producing Escherichia coli

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