Immunotoxicological Evaluation of Corn Genetically Modified with Bacillus thuringiensis Cry1Ah Gene by a 30-Day Feeding Study in BALB/c Mice

Abstract

This study was to investigate the immunotoxicological potential of corn genetically modified (GM) with Bacillus thuringiensis (Bt) Cry1Ah gene in BALB/c mice. Female BALB/c mice were randomly assigned to one of the four groups: the negative control group, the parental corn group, the GM corn group and the positive control group with 10 mice per group. Mice in the GM corn group and the parental corn group were fed with diets containing 70% corresponding corn for 30 days. Mice in the negative control group and the positive control group were fed with AIN93G diet, administered with saline or 200 mg/kg of cyclophosphamide (CY) via intraperitoneal injection 24 h before the termination of the study, respectively. At the end of the study, the immunotoxicological effects of the GM corn were evaluated through immunopathology parameters including body and organ weights, hematology and clinical chemistry parameters, histological examination, peripheral blood lymphocytes phenotype; humoral immunity including antibody plaque-forming cell, serum immunoglobulin, cytokine and half hemolysis value; cellular immunity such as mitogen-induced splenocyte proliferation, cytotoxic T-lymphocyte reaction, delayed-type hypersensitivity reaction; non-specific immunity including phagocytic activities of phagocytes, natural killer cell activity. A single dose of cyclophosphamide (200 mg/kg bw) was found to have significant adverse effects on immunopathology, cellular immunity, and humoral immunity in mice. The corn genetically modified with Bt Cry1Ah gene is considered consistent with the parental corn in terms of immunopathology, humoral immunity, cellular immunity and non-specific immunity. No adverse immunotoxicological effects of GM corn with Bt Cry1Ah gene were found when feeding mice for 30 days.

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

“…The animals were obtained and purchased from the Laboratory of Animal Physiology, Maulana Malik Ibrahim State Islamic University (Malang, Indonesia). All animals were housed at CDAST, University of Jember (Jember, Indonesia) and maintained under the same conditions with a temperature of 23 to 25 • C, 45% to 55% relative humidity, and a photoperiod of 12 h light/12 h dark [21,22]. Following one week of acclimatization, the animals were divided into the two treatment groups.…”

Effect of feeding transgenic cry1Ab/cry1Ac rice on indices of immune function in broilers

“…IgM is an important indicator for clinical diagnosis of some infectious diseases at early stages and in embryonic infections and can activate complement lysis for bacteria and viruses and has an anti-tumor effect. The present study has shown that at d21 and d 42, no differences existed between broilers fed diets with transgenic rice and the controls Song et al (2014). found…”

“…Their numbers and the ratio of CD4 + to CD8 + T cells reflect overall changes in cellular and humoral immunity and this serves as an important endpoint in immune toxicity experiments Wang et al (2013). found that feeding Cry1Ab protein had no significant effects on the apoptosis rate of blood lymphocytes of Swiss rats Song et al (2014). found that Bacillus thuringiensis Cry1Ah transgenic maize did not statistically change the percentages of T lymphocytes, B lymphocytes, NK cells (CD3-CD49 + ), Th cells, CD8 + T lymphocytes (CD3 + CD8 + , Ts cells) or the Th/Ts ratio in mice.Chen et al (2004) investigated the effect of GM rice with the cowpea trypsin inhibitor gene on immune function of mice.…”

Immunotoxicological Evaluation of Genetically Modified Rice Expressing Cry1Ab/Ac Protein (TT51-1) by a 6-Month Feeding Study on Cynomolgus Monkeys

“…Similar to our findings, Song et al [ 14 ] and Kroghsbo et al [ 9 ] reported that mice or rats fed on Bt crops expressing Cry1Ah or Cry1Ab protein for 30 or 90 days did not exhibit adverse immunotoxicological effects. Although changes in the immune response have previously been observed in fish and mice following Bt maize consumption [ 23 , 24 ], the inconsistency in the results between studies are likely due to the use of different animal models[ 15 ]. Finally, we concluded that monkeys fed on a diet of GM rice containing the Cry1Ab/Ac gene for 6 months did not exhibit adverse immunotoxicological effects.…”

“…Splenocyte suspensions were prepared as described by Song et al [ 15 ]. The spleen was weighed, and a part of the weighed spleen was aseptically transferred to cell culture dishes containing 2 mL of cold PBS.…”