scholarly journals Safety and Immunogenicity of an Enterotoxigenic Escherichia coli Vaccine Patch Containing Heat-Labile Toxin: Use of Skin Pretreatment To Disrupt the Stratum Corneum

2007 ◽  
Vol 75 (5) ◽  
pp. 2163-2170 ◽  
Author(s):  
Gregory M. Glenn ◽  
Christina P. Villar ◽  
David C. Flyer ◽  
A. Louis Bourgeois ◽  
Robin McKenzie ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Stratum Corneum ◽  
Fold Increase ◽  
Enterotoxigenic Escherichia Coli ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cholera Toxin B Subunit ◽  
Natural Immunity ◽  
Patch Application ◽  
Heat Labile

ABSTRACT Transcutaneous immunization allows safe delivery of native heat-labile enterotoxin (LT) from Escherichia coli via application of a simple patch. Physical disruption of the stratum corneum can improve the efficiency of delivery. In the current study, the stratum corneum was disrupted using an electrocardiogram prep pad prior to patch application. The effects were quantified using transepidermal water loss (TEWL) and were correlated with the immune responses. Sixty adults received 50 μg of LT from three lots of LT (20 adults per group) administered in a patch on days 0 and 21. The immunizations were well tolerated. There were no differences in the anti-LT immunoglobulin G (IgG) titers between the three LT lots; the seroconversion rate was 100%, and the mean anti-LT IgG titer was 12,185 enzyme-linked immunosorbent assay units (EU) (a 24-fold increase). TEWL measurements obtained at the time of the second immunization were found to correlate with the day 42 individual increases in the anti-LT IgG titer (r = 0.59, P < 0.001). In a comparative assessment of the immune responses, sera after an LT+ ST+ (E2447A) oral ETEC challenge, which induced moderate to severe diarrhea in 81% of the recipients, had anti-LT IgG titers of 3,245 EU (a 10.8-fold increase). Similarly, the anti-LT IgG titer after administration of an oral cholera toxin B subunit-containing cholera vaccine, which cross-reacts with LT and protects against LT and LT/heat-stable toxin ETEC disease in the field, was 6,741 EU (a 3.3-fold increase). This study confirmed that a well-tolerated regimen for stratum corneum disruption before vaccine patch application results in robust immunity comparable to natural immunity and vaccine-induced immunity and that the magnitude of stratum corneum disruption correlates with the immune response.

scholarly journals Mutants of Type II Heat-Labile Enterotoxin LT-IIa with Altered Ganglioside-Binding Activities and Diminished Toxicity Are Potent Mucosal Adjuvants

2006 ◽  
Vol 75 (2) ◽  
pp. 621-633 ◽  
Author(s):  
Hesham F. Nawar ◽  
Sergio Arce ◽  
Michael W. Russell ◽  
Terry D. Connell
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Binding Activity ◽  
Enzyme Linked Immunosorbent Assay ◽  
Type I ◽  
Type Ii ◽  
Heat Labile ◽  
Enhanced Expression ◽  
Adhesin Protein ◽  
And Function

ABSTRACT The structure and function LT-IIa, a type II heat-labile enterotoxin of Escherichia coli, are closely related to the structures and functions of cholera toxin and LT-I, the type I heat-labile enterotoxins of Vibrio cholerae and enterotoxigenic Escherichia coli, respectively. While LT-IIa is a potent systemic and mucosal adjuvant, recent studies demonstrated that mutant LT-IIa(T34I), which exhibits no detectable binding activity as determined by an enzyme-linked immunosorbent assay, with gangliosides GD1b, GD1a, and GM1 is a very poor adjuvant. To evaluate whether other mutant LT-IIa enterotoxins that also exhibit diminished ganglioside-binding activities have greater adjuvant activities, BALB/c mice were immunized by the intranasal route with the surface adhesin protein AgI/II of Streptococcus mutans alone or in combination with LT-IIa, LT-IIa(T14S), LT-IIa(T14I), or LT-IIa(T14D). All three mutant enterotoxins potentiated strong mucosal immune responses that were equivalent to the response promulgated by wt LT-IIa. All three mutant enterotoxins augmented the systemic immune responses that correlated with their ganglioside-binding activities. Only LT-IIa and LT-IIa(T14S), however, enhanced expression of major histocompatibility complex class II and the costimulatory molecules CD40, CD80, and CD86 on splenic dendritic cells. LT-IIa(T14I) and LT-IIa(T14D) had extremely diminished toxicities in a mouse Y1 adrenal cell bioassay and reduced abilities to induce the accumulation of intracellular cyclic AMP in a macrophage cell line.

scholarly journals The B subunits of cholera and Escherichia coli heat-labile toxins enhance the immune responses in mice orally immunised with a recombinant live P-fimbrial vaccine for avian pathogenic E. coli

2014 ◽  
Vol 62 (3) ◽  
pp. 293-303
Author(s):  
In-Gyeong Oh ◽  
Chetan Jawale ◽  
John Lee
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Cholera Toxin B Subunit ◽  
Adjuvant Effect ◽  
Toxin B ◽  
E Coli ◽  
Cholera Toxin B ◽  
B Subunit ◽  
Heat Labile ◽  
Enterotoxin B

This study aimed to investigate the adjuvant effect of recombinant attenuatedSalmonellaexpressing cholera toxin B subunit (CTB) andEscherichia coliheat-labile enterotoxin B subunit (LTB) for the P-fimbriae subunit-based vaccine of avian pathogenicE. coli(APEC) in a murine model. The PapA-specific sIgA and IgG responses were significantly enhanced after immunisation with theSalmonella-PapA vaccine in the presence of CTB or LTB. The group immunised with theSalmonella-LTB strain promoted Th1-type immunity, whereas that immunised with theSalmonella-CTB strain produced Th2-type immunity. We concluded that bothSalmonella-CTB and -LTB strains can enhance the immune response to PapA, and that the LTB strain may be a more effective adjuvant for APEC vaccination, which requires higher Th1-type immunity for protection. Thus, our findings provide evidence that immunisation with an adjuvant, LTB, is one of the strategies of developing effective vaccines against P-fimbriated APEC.

scholarly journals Safety and Immunogenicity of a Single Oral Dose of Recombinant Double Mutant Heat-Labile Toxin Derived from Enterotoxigenic Escherichia coli

2013 ◽  
Vol 20 (11) ◽  
pp. 1764-1770 ◽  
Author(s):  
Samer S. El-Kamary ◽  
Mitchell B. Cohen ◽  
A. Louis Bourgeois ◽  
Lillian Van De Verg ◽  
Nicole Bauers ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Oral Dose ◽  
Immune Responses ◽  
Single Oral Dose ◽  
Double Mutant ◽  
Phase 1 ◽  
Enterotoxigenic Escherichia Coli ◽  
Heat Labile ◽  
Serum Igg ◽  
Serum Iga

ABSTRACTEnterotoxigenicEscherichia coli(ETEC) is a primary cause of traveler's diarrhea for which there is no licensed vaccine. This phase 1 trial determined the safety and immunogenicity of a recombinantly produced double mutant heat-labile enterotoxin (dmLT) of ETEC. It was administered as a single oral dose of dmLT in escalating doses of 5 μg, 25 μg, 50 μg, and 100 μg, followed by a 72-h inpatient observation, outpatient visits at 8, 14, and 28 days, and telephone calls at 2 and 6 months postvaccination. Safety was assessed by frequency of adverse events, and immune responses determined after immunization included dmLT-specific serum IgA and IgG, fecal IgA, antibody-secreting cells (ASC), and antibodies in lymphocyte supernatant (ALS) responses. All doses were well tolerated by the 36 healthy adults enrolled. Immune responses were limited in the 5- and 25-μg dose recipients. The 50-μg dose recipients trended toward stronger responses than the 100-μg dose recipients by serum IgA (67% versus 33%,P= 0.22), serum IgG (58% versus 33%,P= 0.41), and fecal IgA (58% versus 33%,P= 0.41). By day 14 postvaccination, there were significantly more positive responders (≥4-fold increase from baseline) among the 50- versus 100-μg dose recipients for serum IgA (P= 0.036) but not serum IgG (P= 0.21). In conclusion, a single oral dose of dmLT was well tolerated and immunogenic, with immune responses plateauing at the 50-μg dose. (This clinical trial is registered atwww.clinicaltrials.gov, registration number NCT01147445.)

scholarly journals A Combination Vaccine Consisting of Three Live Attenuated Enterotoxigenic Escherichia coli Strains Expressing a Range of Colonization Factors and Heat-Labile Toxin Subunit B Is Well Tolerated and Immunogenic in a Placebo-Controlled Double-Blind Phase I Trial in Healthy Adults

2011 ◽  
Vol 18 (12) ◽  
pp. 2118-2127 ◽  
Author(s):  
Clayton Harro ◽  
David Sack ◽  
A. Louis Bourgeois ◽  
R. Walker ◽  
Barbara DeNearing ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Immune Responses ◽  
Phase I ◽  
Enterotoxigenic Escherichia Coli ◽  
High Dose ◽  
Double Blind ◽  
Live Attenuated Vaccine ◽  
Content Type ◽  
Heat Labile ◽  
Colonization Factors

ABSTRACTImmune responses against colonization factors (CFs) and the nontoxic B component of the enterotoxigenicEscherichia coli(ETEC) heat-labile toxin (LTB) are considered to be important for immunity against diarrhea caused by ETEC. Individual live attenuated ETEC derivatives that have had their toxin genes removed and whosearoC,ompC, andompFgenes are deleted have shown promise as vaccines against ETEC. The development of such strains has culminated in the testing of a three-strain-combination live attenuated vaccine known as ACE527, comprised of strains ACAM2025 expressing colonization factor antigen I (CFA/I) and LTB; ACAM2022, expressing CS5, CS6, and LTB; and ACAM2027, expressing CS1, CS2, CS3, and LTB. The recombinant CF and LTB genes expressed in the three strains were inserted into the bacterial chromosome to ensure their stable inheritance and expression without the requirement for any selection. ACE527 has been tested in a randomized placebo-controlled, double-blind, phase I safety and immunogenicity study in healthy adult volunteers and proved to be well tolerated and immunogenic at dose levels of 1010and 1011total CFU. There was no indication of strain interference on the basis of fecal shedding patterns, with all three being detected in the feces of 50% and 83% of low- and high-dose vaccine recipients, respectively. Similarly, strong immune responses to LTB and to CFs expressed on all three constituent strains were induced, with at least 50% of subjects in the high-dose group responding to LTB, CFA/I, CS3, and CS6.

scholarly journals Intradermal or Sublingual Delivery and Heat-Labile Enterotoxin Proteins Shape Immunologic Responses to a CFA/I Fimbria-Derived Subunit Antigen Vaccine against Enterotoxigenic Escherichia coli

2019 ◽  
Vol 87 (11) ◽  
Author(s):  
Milton Maciel ◽  
David Bauer ◽  
Robin L. Baudier ◽  
Jacob Bitoun ◽  
John D. Clements ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibody Responses ◽  
Enterotoxigenic Escherichia Coli ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cell Agglutination ◽  
Local Skin ◽  
Content Type ◽  
B Subunit ◽  
Heat Labile ◽  
Functional Antibodies

ABSTRACT Enterotoxigenic Escherichia coli (ETEC) is a major cause of infectious diarrhea in children, travelers, and deployed military personnel. As such, development of a vaccine would be advantageous for public health. One strategy is to use subunits of colonization factors combined with antigen/adjuvant toxoids as an ETEC vaccine. Here, we investigated the intradermal (i.d.) or sublingual (s.l.) delivery of CFA/I fimbrial antigens, including CfaEB and a CfaE-heat-labile toxin B subunit (LTB) chimera admixed with double mutant heat-labile toxin (LT) LT-R192G/L211A (dmLT). In addition, we compared dmLT with other LT proteins to better understand the generation of adjuvanted fimbrial and toxoid immunity as well as the influence on any local skin reactogenicity. We demonstrate that immunization with dmLT admixed with CfaEB induces robust serum and fecal antibody responses to CFA/I fimbriae and LT but that i.d. formulations are not optimal for s.l. delivery. Improved s.l. vaccination outcomes were observed when higher doses of dmLT (1 to 5 μg) were admixed with CfaEB or, even better, when a CfaE-LTB chimera antigen was used instead. Serum anti-CFA/I total antibodies, detected by enzyme-linked immunosorbent assay, were the best predictor of functional antibodies, based on the inhibition of red blood cell agglutination by ETEC. Immunization with other LT proteins or formulations with altered B-subunit binding during i.d. immunization (e.g., by addition of 5% lactose, LTA1, or LT-G33D) minimally altered the development of antibody responses and cytokine recall responses but reduced skin reactogenicity at the injection site. These results reveal how formulations and delivery parameters shape the adaptive immune responses to a toxoid and fimbria-derived subunit vaccine against ETEC.

scholarly journals Induction of Systemic Antifimbria and Antitoxin Antibody Responses in Egyptian Children and Adults by an Oral, Killed Enterotoxigenic Escherichia coli plus Cholera Toxin B Subunit Vaccine

2001 ◽  
Vol 69 (5) ◽  
pp. 2853-2857 ◽  
Author(s):  
Eric R. Hall ◽  
Thomas F. Wierzba ◽  
Christina Åhrén ◽  
Malla R. Rao ◽  
Samir Bassily ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Cholera Toxin ◽  
Enterotoxigenic Escherichia Coli ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cholera Toxin B Subunit ◽  
Igg Antibodies ◽  
Toxin B ◽  
Cholera Toxin B ◽  
B Subunit ◽  
Egyptian Children

ABSTRACT We assessed serologic responses to an oral, killed whole-cell enterotoxigenic Escherichia coli plus cholera toxin B-subunit (ETEC-rCTB) vaccine in 73 Egyptian adults, 105 schoolchildren, and 93 preschool children. Each subject received two doses of vaccine or placebo 2 weeks apart, giving blood before immunization and 7 days after each dose. Plasma antibodies to rCTB and four vaccine-shared colonization factors (CFs) were measured by enzyme-linked immunosorbent assay. Immunoglobulin A (IgA) antibodies to rCTB and CFA/I were measured in all subjects, and those against CS1, CS2, and CS4 were measured in all children plus a subset of 33 adults. IgG antibodies to these five antigens were measured in a subset of 30 to 33 subjects in each cohort. Seroconversion was defined as a >2-fold increase in titer after vaccination. IgA and IgG seroconversion to rCTB was observed in 94 to 95% of adult vaccinees, with titer increases as robust as those previously reported for these two pediatric cohorts. The proportion showing IgA seroconversion to each CF antigen among vaccinated children (range, 70 to 96%) and adults (31 to 69%), as well as IgG seroconversion in children (44 to 75%) and adults (25 to 81%), was significantly higher than the corresponding proportion in placebo recipients, except for IgA responses to CS2 in adults. IgA anti-CF titers peaked after one dose in children, whereas in all age groups IgG antibodies rose incrementally after each dose. Independently, both preimmunization IgA titer and age were inversely related to the magnitude of IgA responses. In conclusion, serologic responses to the ETEC-rCTB vaccine may serve as practical immune outcome measures in future pediatric trials in areas where ETEC is endemic.

scholarly journals Immunogenicity and protective efficacy of enterotoxigenic Escherichia coli (ETEC) total RNA against ETEC challenge in a mouse model

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Mandi Liu ◽  
Yue Zhang ◽  
Di Zhang ◽  
Yun Bai ◽  
Guomei Liu ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Mouse Model ◽  
Immune Responses ◽  
Protective Efficacy ◽  
Enterotoxigenic Escherichia Coli ◽  
Economic Losses ◽  
Th2 Response ◽  
Total Rna ◽  
Etec Infection

AbstractEnterotoxigenic Escherichia coli (ETEC), an essential cause of post-weaning diarrhea (PWD) in piglets, leads to significant economic losses to the pig industry. The present study aims to identify the role of ETEC total RNA in eliciting immune responses to protect animals against ETEC infection. The results showed that the total RNA isolated from pig-derived ETEC K88ac strain effectively stimulated the IL-1β secretion of porcine intestinal epithelial cells (IPEC-J2). The mouse model immunized with ETEC total RNA via intramuscular injection (IM) or oral route (OR) was used to evaluate the protective efficiency of the ETEC total RNA. The results suggested that 70 μg ETEC total RNA administered by either route significantly promoted the production of the serum IL-1β and K88ac specific immunoglobulins (IgG, IgM, and IgA). Besides, the ETEC RNA administration augmented strong mucosal immunity by elevating K88ac specific IgA level in the intestinal fluid. Intramuscularly administered RNA induced a Th1/Th2 shift toward a Th2 response, while the orally administered RNA did not. The ETEC total RNA efficiently protected the animals against the ETEC challenge either by itself or as an adjuvant. The histology characterization of the small intestines also suggested the ETEC RNA administration protected the small intestinal structure against the ETEC infection. Particularly of note was that the immunity level and protective efficacy caused by ETEC RNA were dose-dependent. These findings will help understand the role of bacterial RNA in eliciting immune responses, and benefit the development of RNA-based vaccines or adjuvants.

Use of a Multiplex PCR System for the Simultaneous Detection of Heat Labile Toxin I and Heat Stable Toxin II Genes of Enterotoxigenic Escherichia coli in Skim Milk and Porcine Stool

1998 ◽  
Vol 61 (2) ◽  
pp. 141-145 ◽  
Author(s):  
HAU-YANG TSEN ◽  
LIANG-ZHAO JIAN ◽  
WAN-RONG CHI
Keyword(s):  
Escherichia Coli ◽  
Multiplex Pcr ◽  
Simultaneous Detection ◽  
Skim Milk ◽  
Pcr Primers ◽  
Enterotoxigenic Escherichia Coli ◽  
Farm Animals ◽  
Target Cells ◽  
Heat Stable ◽  
Heat Labile

Enterotoxigenic Escherichia coli (ETEC) strains which produce heat labile and/or heat stable toxins (LT and ST) may cause diarrhea in humans and farm animals. Using PCR primers specific for the LT I and ST II genes, a multiplex PCR system which allows detection of LT I- and ST II-producing ETEC strains was developed. When skim milk was used for a PCR assay, it was found that if target cells in the sample were precultured in MacConkey broth for 8 h prior to PCR as few as 100 cells per ml of the sample could be detected. Without the preculture step, 104 CFU of target cells per 0.2 g of porcine stool specimen were required to generate visible PCR products. The multiplex PCR System can be used for rapid testing of fecal specimens, food and possibly environmental samples for the presence of ETEC strains.

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