scholarly journals Lipopolysaccharide as an Antigen Target for the Formulation of a Universal Vaccine against Escherichia coli O111 Strains

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 ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Response ◽  
Structural Variations ◽  
Universal Vaccine ◽  
E Coli ◽  
Humoral Immune ◽  
The Core ◽  
Repeat Units ◽  
Typical Epec ◽  
Different Strains

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.

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
Keyword(s):  
Escherichia Coli ◽  
Immune Response ◽  
Cholera Toxin ◽  
Horse Serum ◽  
Oral Immunization ◽  
Escherichia Coli O157 ◽  
E Coli ◽  
Humoral Immune ◽  
Unvaccinated Control ◽  
Glycoconjugate Vaccine

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.

scholarly journals Differences in systemic humoral immune response among Balb/c mice administered with probiotic, LPS Escherichia coli, and probiotic-LPS E. coli

2019 ◽  
Author(s):  
Kurniawan Taufiq Kadafi ◽  
Satrio Wibowo
Keyword(s):  
Escherichia Coli ◽  
Immune Response ◽  
Humoral Immune Response ◽  
Control Group ◽  
E Coli ◽  
Humoral Immune ◽  
Treatment Regimens ◽  
Humoral Immune Responses ◽  
Group 4 ◽  
Group 2

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.

scholarly journals Bovine Immune Response to Shiga-Toxigenic Escherichia coli O157:H7

2006 ◽  
Vol 13 (12) ◽  
pp. 1322-1327 ◽  
Author(s):  
Mark A. Hoffman ◽  
Christian Menge ◽  
Thomas A. Casey ◽  
William Laegreid ◽  
Brad T. Bosworth ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Pathogenic Bacteria ◽  
O157 Strain ◽  
Fecal Shedding ◽  
E Coli ◽  
Humoral Immune ◽  
Cellular Immune Responses ◽  
Different Strains ◽  
Cellular Immune

ABSTRACT Although cattle develop humoral immune responses to Shiga-toxigenic (Stx+) Escherichia coli O157:H7, infections often result in long-term shedding of these human pathogenic bacteria. The objective of this study was to compare humoral and cellular immune responses to Stx+ and Stx− E. coli O157:H7. Three groups of calves were inoculated intrarumenally, twice in a 3-week interval, with different strains of E. coli: a Stx2-producing E. coli O157:H7 strain (Stx2+O157), a Shiga toxin-negative E. coli O157:H7 strain (Stx−O157), or a nonpathogenic E. coli strain (control). Fecal shedding of Stx2+O157 was significantly higher than that of Stx−O157 or the control. Three weeks after the second inoculation, all calves were challenged with Stx2+O157. Following the challenge, levels of fecal shedding of Stx2+O157 were similar in all three groups. Both groups inoculated with an O157 strain developed antibodies to O157 LPS. Calves initially inoculated with Stx−O157, but not those inoculated with Stx2+O157, developed statistically significant lymphoproliferative responses to heat-killed Stx2+O157. These results provide evidence that infections with STEC can suppress the development of specific cellular immune responses in cattle, a finding that will need to be addressed in designing vaccines against E. coli O157:H7 infections in cattle.

Polyester Cloth–Based Hybridization Array System for Identification of Enterohemorrhagic Escherichia coli Serogroups O26, O45, O103, O111, O121, O145, and O157

2012 ◽  
Vol 75 (9) ◽  
pp. 1691-1697 ◽  
Author(s):  
BURTON W. BLAIS ◽  
MARTINE GAUTHIER ◽  
MYLÈNE DESCHÊNES ◽  
GEORGE HUSZCZYNSKI
Keyword(s):  
Escherichia Coli ◽  
Marker Gene ◽  
Enterohemorrhagic Escherichia Coli ◽  
Oligonucleotide Probes ◽  
E Coli ◽  
Polyester Cloth ◽  
Gene Profiles ◽  
Pcr Products ◽  
Different Strains ◽  
Immunoenzymatic Assay

A cloth-based hybridization array system (CHAS) was developed for the identification of foodborne colony isolates of seven priority enterohemorrhagic Escherichia coli (EHEC-7) serogroups targeted by U.S. food inspection programs. Gene sequences associated with intimin; Shiga-like toxins 1 and 2; and the antigenic markers O26, O45, O103, O111, O121, O145, and O157 were amplified in a multiplex PCR incorporating a digoxigenin label, and detected by hybridization of the PCR products with an array of specific oligonucleotide probes immobilized on a polyester cloth support, with subsequent immunoenzymatic assay of the captured amplicons. The EHEC-7 CHAS exhibited 100% inclusivity and 100% exclusivity characteristics with respect to detection of the various markers among 89 different E. coli strains, with various marker gene profiles and 15 different strains of non–E. coli bacteria.

Alteration of the phagocytosis and antimicrobial defense of Octodonta nipae (Coleoptera: Chrysomelidae) pupae to Escherichia coli following parasitism by Tetrastichus brontispae (Hymenoptera: Eulophidae)

2018 ◽  
Vol 109 (2) ◽  
pp. 248-256
Author(s):  
E. Meng ◽  
J. Li ◽  
B. Tang ◽  
Y. Hu ◽  
T. Qiao ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Response ◽  
Immune Responses ◽  
Mrna Expression ◽  
Bactericidal Activity ◽  
Bacterial Infections ◽  
Expression Level ◽  
Primary Immune Response ◽  
Mrna Expression Level ◽  
E Coli

AbstractAlthough parasites and microbial pathogens are both detrimental to insects, little information is currently available on the mechanism involved in how parasitized hosts balance their immune responses to defend against microbial infections. We addressed this in the present study by comparing the immune response between unparasitized and parasitized pupae of the chrysomelid beetle, Octodonta nipae (Maulik), to Escherichia coli invasion. In an in vivo survival assay, a markedly reduced number of E. coli colony-forming units per microliter was detected in parasitized pupae at 12 and 24 h post-parasitism, together with decreased phagocytosis and enhanced bactericidal activity at 12 h post-parasitism. The effects that parasitism had on the mRNA expression level of selected antimicrobial peptides (AMPs) of O. nipae pupae showed that nearly all transcripts of AMPs examined were highly upregulated during the early and late parasitism stages except defensin 2B, whose mRNA expression level was downregulated at 24 h post-parasitism. Further elucidation on the main maternal fluids responsible for alteration of the primary immune response against E. coli showed that ovarian fluid increased phagocytosis at 48 h post-injection. These results indicated that the enhanced degradation of E. coli in parasitized pupae resulted mainly from the elevated bactericidal activity without observing the increased transcripts of target AMPs. This study contributes to a better understanding of the mechanisms involved in the immune responses of a parasitized host to bacterial infections.

scholarly journals Efficient production of (S)-1-phenyl-1, 2-ethanediol using xylan as co-substrate by a coupled multi-enzyme Escherichia coli system

2020 ◽  
Author(s):  
Junchao Rao ◽  
Rongzhen Zhang ◽  
Guanyu Xu ◽  
Lihong Li ◽  
Yan Xu
Keyword(s):  
Escherichia Coli ◽  
Glucose Dehydrogenase ◽  
Optical Purity ◽  
Carbonyl Reductase ◽  
Cofactor Regeneration ◽  
Efficient Production ◽  
Chiral Synthesis ◽  
E Coli ◽  
Concomitant Reduction ◽  
Different Strains

Abstract Background: ( S )-1-phenyl-1,2-ethanediol is an important chiral intermediate in the synthesis of liquid crystals and chiral biphosphines.(S)-carbonyl reductase II from Candida parapsilosis catalyzes the conversion of 2-hydroxyacetophenone to ( S )-1-phenyl-1,2-ethanediol with NADPH as a cofactor. Glucose dehydrogenase with a Ala258Phe mutation is able to catalyze the oxidation of xylose with concomitant reduction of NADP + to NADPH, while endo-β-1,4-xylanase 2 catalyzes the conversion of xylan to xylose. In the present work, the Ala258Phe glucose dehydrogenase mutant and endo-β-1,4-xylanase 2 were introduced into the ( S )-carbonyl reductase II-mediated chiral pathway to strengthen cofactor regeneration by using xylan as a naturally abundant co-substrate. Results: We constructed several coupled multi-enzyme systems by introducing ( S )-carbonyl reductase II, the A258F glucose dehydrogenase mutant and endo-β-1,4-xylanase 2 into Escherichia coli . Different strains were produced by altering the location of the encoding genes on the plasmid. Only recombinant E. coli /pET-G-S-2 expressed all three enzymes, and this strain produced ( S )-1-phenyl-1,2-ethanediol from 2-hydroxyacetophenone as a substrate and xylan as a co-substrate. The optical purity was 100% and the yield was 98.3% (6 g/L 2-HAP) under optimal conditions of 35°C, pH 6.5 and a 2:1 substrate-co-substrate ratio. The introduction of A258F glucose dehydrogenase and endo-β-1,4-xylanase 2 into the ( S )-carbonyl reductase II-mediated chiral pathway caused a 54.6% increase in yield, and simultaneously reduced the reaction time from 48 h to 28 h. Conclusions: This study demonstrates efficient chiral synthesis using a pentose as a co-substrate to enhance cofactor regeneration. This provides a new approach for enantiomeric catalysis through the inclusion of naturally abundant materials.

scholarly journals Molecular Characterization of Commensal Escherichia coli Adapted to Different Compartments of the Porcine Gastrointestinal Tract

2012 ◽  
Vol 78 (19) ◽  
pp. 6799-6803 ◽  
Author(s):  
Sam Abraham ◽  
David M. Gordon ◽  
James Chin ◽  
Huub J. M. Brouwers ◽  
Peter Njuguna ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gastrointestinal Tract ◽  
Random Amplified Polymorphic Dna ◽  
Content Type ◽  
E Coli ◽  
Plasmid Replicon ◽  
Different Strains ◽  
Different Characteristics

ABSTRACTThe role ofEscherichia colias a pathogen has been the focus of considerable study, while much less is known about it as a commensal and how it adapts to and colonizes different environmental niches within the mammalian gut. In this study, we characterizeEscherichia coliorganisms (n= 146) isolated from different regions of the intestinal tracts of eight pigs (dueodenum, ileum, colon, and feces). The isolates were typed using the method of random amplified polymorphic DNA (RAPD) and screened for the presence of bacteriocin genes and plasmid replicon types. Molecular analysis of variance using the RAPD data showed thatE. coliisolates are nonrandomly distributed among different gut regions, and that gut region accounted for 25% (P< 0.001) of the observed variation among strains. Bacteriocin screening revealed that a bacteriocin gene was detected in 45% of the isolates, with 43% carrying colicin genes and 3% carrying microcin genes. Of the bacteriocins observed (H47, E3, E1, E2, E7, Ia/Ib, and B/M), the frequency with which they were detected varied with respect to gut region for the colicins E2, E7, Ia/Ib, and B/M. The plasmid replicon typing gave rise to 25 profiles from the 13 Inc types detected. Inc F types were detected most frequently, followed by Inc HI1 and N types. Of the Inc types detected, 7 were nonrandomly distributed among isolates from the different regions of the gut. The results of this study indicate that not only may the different regions of the gastrointestinal tract harbor different strains ofE. colibut also that strains from different regions have different characteristics.

scholarly journals The Complete Genome of the Atypical Enteropathogenic Escherichia coli Archetype Isolate E110019 Highlights a Role for Plasmids in Dissemination of the Type III Secreted Effector EspT

2019 ◽  
Vol 87 (10) ◽  
Author(s):  
Tracy H. Hazen ◽  
David A. Rasko
Keyword(s):  
Escherichia Coli ◽  
Complete Genome ◽  
Genomic Analysis ◽  
Host Cells ◽  
Comparative Genomic ◽  
Content Type ◽  
E Coli ◽  
Type Iii ◽  
Severe Diarrhea ◽  
Typical Epec

ABSTRACT Enteropathogenic Escherichia coli (EPEC) is a leading cause of moderate to severe diarrhea among young children in developing countries, and EPEC isolates can be subdivided into two groups. Typical EPEC (tEPEC) bacteria are characterized by the presence of both the locus of enterocyte effacement (LEE) and the plasmid-encoded bundle-forming pilus (BFP), which are involved in adherence and translocation of type III effectors into the host cells. Atypical EPEC (aEPEC) bacteria also contain the LEE but lack the BFP. In the current report, we describe the complete genome of outbreak-associated aEPEC isolate E110019, which carries four plasmids. Comparative genomic analysis demonstrated that the type III secreted effector EspT gene, an autotransporter gene, a hemolysin gene, and putative fimbrial genes are all carried on plasmids. Further investigation of 65 espT-containing E. coli genomes demonstrated that different espT alleles are associated with multiple plasmids that differ in their overall gene content from the E110019 espT-containing plasmid. EspT has been previously described with respect to its role in the ability of E110019 to invade host cells. While other type III secreted effectors of E. coli have been identified on insertion elements and prophages of the chromosome, we demonstrated in the current study that the espT gene is located on multiple unique plasmids. These findings highlight a role of plasmids in dissemination of a unique E. coli type III secreted effector that is involved in host invasion and severe diarrheal illness.

scholarly journals Masking of antigenic epitopes by antibodies shapes the humoral immune response to influenza

2015 ◽  
Vol 370 (1676) ◽  
pp. 20140248 ◽  
Author(s):  
Veronika I. Zarnitsyna ◽  
Ali H. Ellebedy ◽  
Carl Davis ◽  
Joshy Jacob ◽  
Rafi Ahmed ◽  
...  
Keyword(s):  
Immune Response ◽  
Influenza A ◽  
Complex Dynamics ◽  
Surface Glycoprotein ◽  
Published Data ◽  
Original Strain ◽  
Universal Vaccine ◽  
Humoral Immune ◽  
Multiple Strains ◽  
Antigenic Epitopes

The immune responses to influenza, a virus that exhibits strain variation, show complex dynamics where prior immunity shapes the response to the subsequent infecting strains. Original antigenic sin (OAS) describes the observation that antibodies to the first encountered influenza strain, specifically antibodies to the epitopes on the head of influenza's main surface glycoprotein, haemagglutinin (HA), dominate following infection with new drifted strains. OAS suggests that responses to the original strain are preferentially boosted. Recent studies also show limited boosting of the antibodies to conserved epitopes on the stem of HA, which are attractive targets for a ‘universal vaccine’. We develop multi-epitope models to explore how pre-existing immunity modulates the immune response to new strains following immunization. Our models suggest that the masking of antigenic epitopes by antibodies may play an important role in describing the complex dynamics of OAS and limited boosting of antibodies to the stem of HA. Analysis of recently published data confirms model predictions for how pre-existing antibodies to an epitope on HA decrease the magnitude of boosting of the antibody response to this epitope following immunization. We explore strategies for boosting of antibodies to conserved epitopes and generating broadly protective immunity to multiple strains.

scholarly journals Induced immune response of Escherichia coli BL21 expressing recombinant MSP1a and MSP1b proteins of Anaplasma marginale

2009 ◽  
Vol 52 (spe) ◽  
pp. 113-120 ◽  
Author(s):  
Katia Tamekuni ◽  
Marilda Carlos Vidotto ◽  
Samuel Rodrigues Felix ◽  
Michelle Igarashi ◽  
João Luis Garcia ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Response ◽  
Western Blot ◽  
Molecular Mass ◽  
Outer Membrane ◽  
Humoral Response ◽  
Anaplasma Marginale ◽  
E Coli ◽  
Escherichia Coli Bl21 ◽  
Molecular Masses

This work aims to evaluate the potential of immunization with E. coli BL21 expressing the recombinant rMSP1a and rMSP1b proteins of Anaplasma marginale. E. coli BL21 was transformed with recombinant plasmids pET102/msp1α and pET101/msp1β, and rMSP1a and rMSP1b were expressed after induction by IPTG. BALB/c mice were vaccinated with formolized BL21/rMSP1a and BL21/rMSP1b, and the production in mice sera of whole IgG was determined by ELISA. The mice immunized with BL21/rMSP1a showed a better humoral response for whole IgG when compared to the mice immunized with BL21/rMSP1b; these mice exhibited a small response after the second vaccination. Sera of mice immunized with BL21/rMSP1a reacted via western blot with BL21 and rMSP1a, with molecular masses varying from 70 to 105 kDa. Sera of mice immunized with BL21/rMSP1b reacted with BL21 and rMSP1b with a molecular mass of 100 kDa. These results demonstrate that BL21 containing rMSP1a and rMSP1b in the outer membrane were able to produce an immune response in mice, reinforcing its use in vaccine models against bovine anaplasmosis.

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