Oral immunization of mice with a glycoconjugate vaccine containing the O157 antigen of Escherichia coli O157:H7 admixed with cholera toxin fails to elicit protection against subsequent colonization by the pathogen

2000 ◽  
Vol 46 (3) ◽  
pp. 283-290 ◽  
Author(s):  
J Wayne Conlan ◽  
Rhonda KuoLee ◽  
Ann Webb ◽  
Andrew D Cox ◽  
Malcolm B Perry

It has been postulated that a humoral immune response directed against the O157 antigen of Escherichia coli O157:H7, and expressed in the intestine, might afford protection from colonization and consequent infection by this enteric pathogen. The present study was conducted to determine whether such an immune response can be experimentally generated in mice. To this end, mice were orally immunized with a glycoconjugate vaccine consisting of horse serum albumin and the O157 polysaccharide admixed with the mucosal adjuvant, cholera toxin. Mice consistently developed robust local and systemic immune responses to the cholera toxin adjuvant, but were far from uniformly reactive to the test vaccine. Moreover, vaccinated mice were as susceptible to transient intestinal colonization following challenge with an isolate of E. coli O157:H7 as unvaccinated control mice. These results indicate that this vaccination approach is unlikely to be straightforward in target bovine or human hosts.Key words: Escherichia coli O157:H7, glycoconjugate vaccine, mucosal immunity, mice.

1999 ◽  
Vol 45 (4) ◽  
pp. 279-286
Author(s):  
J Wayne Conlan ◽  
Andrew D Cox ◽  
Rhonda KuoLee ◽  
Ann Webb ◽  
Malcolm B Perry

The results of the present study show that whereas both BALB/c and C57BL/6 mice parenterally inoculated with a horse serum albumin - Escherichia coli O157 antigen conjugate vaccine develop systemic, specific antibodies to the carrier protein, only the former mice routinely develop antibodies to the carbohydrate O157 moiety. However, little convincing evidence was found to show that these antibodies transuded into the intestinal tract either naturally or in response to an oral inoculum of the pathogen. Moreover, this vaccination procedure failed to protect mice against intestinal colonization following oral challenge with the pathogen. Thus, the results of this study suggest that parenteral vaccination might be an unsuitable strategy for combatting E. coli O157:H7 organisms located in the gut.Key words: Escherichia coli, glycoconjugate vaccine, mice.


2013 ◽  
Vol 82 (2) ◽  
pp. 893-902 ◽  
Author(s):  
Kristel Lourdault ◽  
Long-Chieh Wang ◽  
Ana Vieira ◽  
James Matsunaga ◽  
Rita Melo ◽  
...  

ABSTRACTLeptospirosis is a potentially fatal zoonosis transmitted by reservoir host animals that harbor leptospires in their renal tubules and shed the bacteria in their urine.Leptospira interrogansserovar Copenhageni transmitted fromRattus norvegicusto humans is the most prevalent cause of urban leptospirosis. We examinedL. interrogansLigA, domains 7 to 13 (LigA7-13), as an oral vaccine delivered byEscherichia colias a lipidated, membrane-associated protein. The efficacy of the vaccine was evaluated in a susceptible hamster model in terms of the humoral immune response and survival from leptospiral challenge. Four weeks of oral administration of liveE. coliexpressing LigA7-13 improved survival from intraperitoneal (i.p.) and intradermal (i.d.) challenge byL. interrogansserovar Copenhageni strain Fiocruz L1-130 in Golden Syrian hamsters. Immunization withE. coliexpressing LigA7-13 resulted in a systemic antibody response, and a significant LigA7-13 IgG level after the first 2 weeks of immunization was completely predictive of survival 28 days after challenge. As in previous LigA vaccine studies, all immunized hamsters that survived infection had renal leptospiral colonization and histopathological changes. In summary, an oral LigA-based vaccine improved survival from leptospiral challenge by either the i.p. or i.d. route.


Author(s):  
Kurniawan Taufiq Kadafi ◽  
Satrio Wibowo

Background and Objectives: The aim of this study was to compare the systemic humoral immune responses, including IgE, IgA, IgG and IgM levels in Balb/c mice administered a probiotic, LPS derived from Escherichia coli (E.coli), and probiot- ic-LPS derived from E. coli. Materials and Methods: Thirty-two male Balb/c mice, 10-12 weeks of age with body weight ranging from 30-40 g were randomly divided into four experimental groups (n=8). The treatment regimens were as follows: Group 1, mice did not receive LPS or probiotic (control group); Group 2, mice received only LPS on the first day; Group 3, mice received probi- otic for 7 days; Group 4, mice received LPS on the first day, and then continued, with probiotic for 7 days. The mice were observed for 8 days, and then, euthanized the next day (day 9). The serum was collected, and the levels of IgE, IgA, IgG and IgM were measured using ELISA. Results: The humoral immune response was higher in the presence of a probiotic compared to that in the control; IgE (9.02 ± 0.58 units/ml, p=0.000), IgA (3.26 ± 0.99 units/ml, p=0.316), IgG (7.29 ± 0.24 units/ml, p=0.000), and IgM (4.01 ± 2.98 units/ml, p=0.505). When administered with LPS E. coli along with probiotic, the humoral immune response was the highest; IgE (10.68 ± 1.63 units/ml, p=0.000), IgA (8.34 ± 1.47 units/ml, p=0.000), IgG (9.96 ± 0.98 units/ml, p=0.000), and IgM (4.31 ± 1.05 units/ml, p=0.319) compared to the control group. Conclusion: Probiotic-LPS derived from E. coli treatment induced a higher humoral immune response (highest IgE, IgA, IgG and IgM levels) compared to treatment with probiotic only.


2004 ◽  
Vol 321 (1) ◽  
pp. 192-196 ◽  
Author(s):  
Ana Paula Mattos Arêas ◽  
Maria Leonor Sarno Oliveira ◽  
Eliane Namie Miyaji ◽  
Luciana Cezar Cerqueira Leite ◽  
Karina Araújo Aires ◽  
...  

1999 ◽  
Vol 45 (9) ◽  
pp. 723-731 ◽  
Author(s):  
J Wayne Conlan ◽  
Rhonda KuoLee ◽  
Ann Webb ◽  
Malcolm B Perry

The present study was performed to assess the potential of a humoral mucosal immune response directed against the O157 antigen of Escherichia coli O157:H7 to prevent intestinal colonization by the pathogen. To this end, mice were gavaged with inocula of Salmonella landau, a Salmonella strain that naturally expresses the O157 antigen. Salmonella landau was avirulent for mice. Despite this, mice exposed to S. landau developed high titres of serum and coproantibodies against the O157 antigen. These mice, compared with controls, demonstrated some ability to resist transient intestinal colonization by an oral inoculum of an isolate of E. coli O157:H7. These findings suggest that a local immune response directed against the O157 antigen might increase host resistance to this pathogen.Key words: Salmonella landau, Escherichia coli O157:H7, mucosal immunity, mice.


2010 ◽  
Vol 17 (11) ◽  
pp. 1772-1780 ◽  
Author(s):  
Maurílio F. Santos ◽  
Roger R. C. New ◽  
Gabrielle R. Andrade ◽  
Christiane Y. Ozaki ◽  
Osvaldo A. Sant'Anna ◽  
...  

ABSTRACT A promising approach to developing a vaccine against O111 strains of diarrheagenic Escherichia coli that exhibit different mechanisms of virulence is to target either the core or the polysaccharide chain (O antigen) of their lipopolysaccharide (LPS). However, due to structural variations found in both these LPS components, to use them as antigen targets for vaccination, it is necessary to formulate a vaccine able to induce a humoral immune response that can recognize all different variants found in E. coli O111 strains. In this study, it was demonstrated that, despite differences in composition of oligosaccharide repeat units between O111ab and O111ac LPS subtypes, antibodies against one O111 subtype can recognize and inhibit the adhesion to human epithelial cells of all categories of O111 E. coli (enteropathogenic E. coli [EPEC], enterohemorrhagic E. coli [EHEC], and enteroaggregative E. coli [EAEC]) strains regardless of the nature of their flagellar antigens, mechanisms of virulence, or O111 polysaccharide subtypes. These antibodies were also able to increase the clearance of different strains of O111 E. coli by macrophages. PCR analyses of the pathways involved in O111 LPS core biosynthesis showed that all EAEC strains have core type R2, whereas typical EPEC and EHEC have core type R3. In contrast, atypical EPEC strains have core types R2 and R3. In summary, the results presented herein indicate that the O111 polysaccharide and LPS core types R2 and R3 are antigen targets for panspecific immunotherapy against all categories of O111 E. coli.


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