4165 total record number 127 records this year

Obtencin de man transgnico mediante el silenciamiento de un gen alergnico

Faustinelli, PC;

Argentina strengthened its position as the world leading exporter of peanuts
(Arachis hypogaea L.) and Córdoba as the first producing province that contributes with
more than 80% of the gross national production. So far, there is no therapy to treat
allergenic reactions produced by peanuts in sensitive patients; therefore, the only way of
preventing such reactions is to avoid consumption. Peanut seeds contain 11 recognized
allergenic proteins, among them the Ara h 2 as the most allergenic one. While in
Argentina peanut consumption is erratic, the novelty of this project is based on our
country’s large export capacity. The focus on the development of new hypoallergenic
varieties that complement the existing commercial offer would allow Argentina to
improve its competitiveness, as well as the supply options for particular market niches in
countries where peanut consumption is widespread and the allergic problems are
significant.The objective of this study was to silence one of the most immunodominant
allergens in peanuts, Ara h 2, using RNA interference allowing the recovery of transgenic
lines with a potentially reduced allergenic content.Somatic embryos of Georgia Green
peanut were transformed via biolistics, with the ara h 2 RNAi construction obtained in the
laboratory. The construction contained an inserted ara h 2 gen fragment, in sense and
antisense positions, separated by a GUS gene segment that allowed the formation of a loop
or hairpin. Gene silencing through RNAi was successful, and 4 lines of peanut with
reduced, and in some cases null content of allergenic proteins of the Ara h 2 type and, by
homology of Ara h 6, were obtained. In the B3.3.1 and B3.3.2 sublines, there was a ~ 90%
reduction of the Ara h 2 protein, still enough to activate allergenic reactions in mice. In the
line B4.6.1 transgenic line, there was a decrease in both the content of the Ara h 2 protein
and also in the content of Ara h 6; and in the B11.1.1 line none of the bands could be
detected by Western blot or by immunodetection, despite containing multiple insertions of
the transgene,.The acquisition of these lines with a partial or total reduction of the Ara h 2
and/or Ara h 6 proteins could mitigate the effect of peanut-induced allergies. Although a
hypoallergenic peanut could not be obtained, these developments foster further research to
obtain peanuts varieties that avoid hypersensitization or which produce delayed immune
reactions, resulting at the end in a decreased percentage of affected children.