Selected articles March 2015
Genetically modified maize that express a bacterial protein does not exert adjuvant effects
Cry1Ab Protein from Bacillus thuringiensis and MON810 cry1Ab-transgenic Maize Exerts No Adjuvant Effect After Airway Exposure
M. Andreassen T. Bøhn, O.-G. Wikmark, J. Van den Berg, M. Løvik, T. Traavik and U. C. Nygaard
In a study by researchers in Norway and South Africa it is shown that pollen or plant material from the genetically modified maize MON810 did not promote allergic responses to a well-known unrelated allergen in a mouse model of airway allergy. This means that this genetically modified maize does not act as an adjuvant, a concern that have been raised when discussing the safety for consumers of transgenic crop plants.
The genetically modified maize used in this study has been inserted with a processed version of a transgene from the soil bacteria Bacillus thuringiensis to express proteins with insecticidal properties. Such proteins may introduce new allergens or act as adjuvants that promote allergic response. The aim of the present study was to investigate whether plant material from this transgenic maize could act as adjuvants towards the unrelated allergen ovalbumin.
A mouse model of airway allergy was used and the known pro allergenic adjuvant cholera toxin was used as a positive control. To investigate the allergic response increase in specific IgE, eosinophils and Th2 cytokines in mediastinal lymph node cell supernatants was measured.
Monica Andreassen is a PhD student in the group and was responsible for the animal experiments, that were conducted both in Norway and South Africa.
– The most fun part of this study has been to work with inspiring researchers in both countries. It was also rewarding to be involved in all the steps in the process – from the planning and the conduction of the experiments to the analyses and the scientific writing. Now I look forward to my PhD dissertation the 19th of March, she says.
The observation that the Bacillus thuringiensis protein from the transgene maize did not exhibit an adjuvant effect similar to that observed with cholera toxin means that the hypothesis of adjuvant effect from insecticidal genetically modified maize was not supported in the mouse model. However, although the doses used in these experiments may represent ”relevant doses”, long-term exposure of the protein should be included in future studies.
Antibodiy-responses against citrullinated proteins in Leishmania patients
Anti-Citrullinated Peptide Antibodies in Sudanese Patients with Leishmania donovani Infection Exhibit Reactivity not Dependent on Citrullination
E. Åhlin, A. I. Elshafie, M. A. M. Nur and J. Rönnelid
Sudanese patients infected with the parasite Leishmania donovani have antibodies against citrullinated peptides, similar to what is seen in patients with reumatoid arthritis. However, the parasite-infected patients, but not the arthritic patients, also show reactivity to the non-citrullinated form of the antigen.
This study was carried out by a Swedish group and Erik Åhlin was a PhD student at the time and did the work as a part of his thesis.
– I was responsible for the work in the lab, and I also compiled the results and analyzed the data, he says.
Infection with Leishmania donovani causes an internal disease called visceral leishmaniasis with an immunopathology characterized by a strong humoral immune response and high production of anti-Leishmania antibodies, circulating immune complexes and polyclonal activation of B-lyphocytes. As inflammation in general is associated with citrullination, the Swedish group sought to investigate antibodiy-responses against citrullinated proteins in Sudanese Leishmania patients.
– I really enjoy the field of diagnostics, it is so exciting, Erik Åhlin says. It is particularly interesting to take the test result further and to dissect what it means, both in a clinical and a methodological meaning.
The findings in the study stress the importance to interpret a positive citrullinated protein/peptide-test carefully when evaluate in non-rheumatic conditions.