Comparative study of the adjuvanticity ofBacillus thuringiensisCry1Ab protein and cholera toxin on allergic sensitisation and elicitation to peanut

Abstract

We aimed to investigate the adjuvanticity of Cry1Ab on allergic sensitisation and elicitation to peanut in mice, in comparison with cholera toxin (CT), a known mucosal Th2 adjuvant. Balb/c mice were gavaged with phosphate buffer saline (PBS) (control), peanut protein extract (PE) alone or PE co-administered either with CT or Cry1Ab. Peanut-specific IgE, IgG1 and IgG2a and Th1/Th2/Th17 cytokine secretion by splenocytes were assayed. Gavaged mice were further challenged with PE. Markers of the immediate and late phases of the allergic reaction were assayed in bronchoalveolar lavages (BAL) fluids collected 10 minutes or 36 hours after airway challenge, respectively. Sensitisation to peanut was only observed in mice receiving PE plus CT, as demonstrated by specific IgE and IgG1 production in sera and secretion of Th2 (and Th17) cytokines by splenocytes. Following challenge, mice sensitised with PE plus CT produced leukotrienes (LT) E4 and C4, then Th2/Th17-cytokines and showed eosinophil/neutrophil influx in BAL. Interestingly, LT production, Th2/Th17 cytokine release and eosinophil influx were also significant in mice gavaged with PE plus Cry1Ab, but not with PBS or PE alone. Cry1Ab did not demonstrate adjuvant effects on oral sensitisation to peanut. However, this study shows possible adjuvant properties of Cry1Ab on the elicitation of the allergic reaction, at least in the Balb/c mouse model and in the experimental conditions used.

No Adjuvant Effect of Bacillus thuringiensis-Maize on Allergic Responses in Mice

“…It is possible that protein denaturation of Cry1Ab during food processing might reduce the amount of Cry1Ab in the food, but this is very unlikely because steam pelleting at 70°C is a gentle process. Nevertheless, the amount of Cry1Ab ingested from a steady diet of Bt -maize including potential denaturation of the protein is likely to be higher than previous studies using gavage in which 100 µg of Cry1Ab was provided on days 0 and 15 in one study [25] and in another study, mice were gavaged with a total of 50 µg of Cry1Ab on 5 different days [20]. Compared to gavage treatment with purified protein, mice in our experiments consumed similar or even higher amounts of Cry1Ab without adjuvant effects.…”

Humoral and cellular immune response in Wistar Han RCC rats fed two genetically modified maize MON810 varieties for 90 days (EU 7th Framework Programme project GRACE)

“…the capacity to enhance the immunogenicity of and induce the sensitisation to an unrelated protein with which it is co-administered, Guimaraes et al (2008) showed that the oral administration of Cry1Ab did not increase the sensitization to peanut proteins but observed a possible impact on the elicitation of the allergic reaction in the BALB/c mouse model. Adel-Patient et al (2011) observed a significant production of IgE and IgG1 antibodies specific to maize proteins induced after intragastric sensitization with an extract of MON810 maize in the presence of a mucosal Th2 adjuvant in BALB/c mice when compared to PBS-treated mice.…”

Lien hypothétique entre l’endométriose et l’accumulation de xénobiotiques associés aux aliments génétiquement modifiés

“…Le potentiel adjuvant de Cry1Ab a é galement é té dé montré . L'administration de la proté ine conjointement à un extrait de proté ine d'arachide a conduit à une production de leucotriè nes et de cytokines Th2 et Th17 augmenté e par rapport à l'extrait seul [26]. De plus, l'administration pendant 90 jours de la proté ine Cry1Ab à un modè le souris induit une ré ponse antigè neanticorps spé cifique et une baisse significative des leucocytes sé riques [27].…”