Lack of Detectable Allergenicity in Genetically Modified Maize Containing “Cry” Proteins as Compared to Native Maize Based on In Silico & In Vitro Analysis

Abstract

BackgroundGenetically modified, (GM) crops with potential allergens must be evaluated for safety and endogenous IgE binding pattern compared to native variety, prior to market release.ObjectiveTo compare endogenous IgE binding proteins of three GM maize seeds containing Cry 1Ab,1Ac,1C transgenic proteins with non GM maize.MethodsAn integrated approach of in silico & in vitro methods was employed. Cry proteins were tested for presence of allergen sequence by FASTA in allergen databases. Biochemical assays for maize extracts were performed. Specific IgE (sIgE) and Immunoblot using food sensitized patients sera (n = 39) to non GM and GM maize antigens was performed.ResultsIn silico approaches, confirmed for non sequence similarity of stated transgenic proteins in allergen databases. An insignificant (p> 0.05) variation in protein content between GM and non GM maize was observed. Simulated Gastric Fluid (SGF) revealed reduced number of stable protein fractions in GM then non GM maize which might be due to shift of constituent protein expression. Specific IgE values from patients showed insignificant difference in non GM and GM maize extracts. Five maize sensitized cases, recognized same 7 protein fractions of 88-28 kD as IgE bindng in both GM and non-GM maize, signifying absence of variation. Four of the reported IgE binding proteins were also found to be stable by SGF.ConclusionCry proteins did not indicate any significant similarity of >35% in allergen databases. Immunoassays also did not identify appreciable differences in endogenous IgE binding in GM and non GM maize.

Immune analysis of cry1Ab-genetically modified potato by in-silico analysis and animal model

“…Our findings are in accordance with the earlier study by Mathur et al [1] on the safety assessment of Cry1Ab, Cry1Ac and Cry1C proteins using in silico tools, where they predicted them as safe for incorporation in GM Maize.…”

“…In the present study, the in silico analysis of Cry1Ab protein used in the transgenic potato indicated no evidence for any similarity between Cry1Ab and any known toxic or allergenic proteins. Thus, our findings confirm the findings of earlier workers [1,8,19]. Moreover, the bioinformatic analysis of NPTII protein in transgenic potato plants showed no significant alignment and homology at the domain level with proteins known to be toxic or bioactive.…”

“…Plant genetic engineering has opened new insights into the development of genetically modified (GM) crops, such as maize, soybean, potato, and cotton with improved agronomically traits [1]. One of the most important applications of transgenic technology is the development of resistant crops to insect pests by introducing insecticidal cry genes from the soil bacterium Bacillus thuringiensis (Bt) [2].…”

“…The major goals of GM crops technology are higher crop production and more nutritious food without the use of pesticides. However, the safety concerns of GM food are determination factors for their acceptance in the market, as defined by scientific and regulatory agencies (e.g., ILSI/ IFBC, FAO/WHO, EFSA/Codex and OECD), to prevent the introduction of known allergens (from any source) in a food crop that did not contain that protein [1,4].…”

Development of Allergenicity and Toxicity Assessment Methods for Evaluating Transgenic Sugarcane Overexpressing Sucrose–Phosphate Synthase

“…The SGF and SIF models provide allergenic potential evaluation methods, since food proteins are rapidly digested by gastric and intestinal processes [3,43]. The combined results of CBB-stained SDS-PAGE gels and Western blotting showed that transgenic sugarcane protein, at time zero as a control sample, underwent no significant degradation changes in the absence of pepsin and trypsin (Figure 2A,B, upper and middle).…”