NOVEL REDUCED-IMMUNOGENICITY WHEAT FOR CELIAC PATIENTS Abstract uri icon

abstract

  • Gluten intolerance and allergy are on the rise throughout the world. The recent demographic studies suggested that the number of people susceptible to gluten is proportional in both hemispheres. Broadly, the incidence of gluten-induced disorders correlates with the level of gluten consumption, wheat acreage, exposure to infectious diseases in the childhood, and the composition of the gut microbiome. Despite increasing incidence and a large number of known cases of gluten sensitivity, allergy, and intolerance the only proven therapy is the gluten exclusion diet. The advent of the genome editing procedures and the novel gene-delivery methods have significantly increased the possibilities of developing creative solutions to this problem. Since, gluten is a complex mixture of proteins, which was encoded by about 70 different genes in the wheat genome. Based on physicochemical properties, these proteins could be classified into two major groups - gliadins, and glutenins, and five sub-groups, namely alpha-, gamma-, and omega-gliadins, and low- as well as highmolecular molecular weight glutenin subunits. A variant of Cas9 dubbed Cas12a (Cpf1) was recently demonstrated to be effective in targeting multiple genes in rice. In parallel, pollen magnetofection, a novel tissue-culture independent genetic transformation method was shown to be effective in delivering genes in cotton, pepper, pumpkin, and lily. Taking the lead from these studies, we decided to induce mutations simultaneously in all immunogenic gliadins and glutenins using LbCpf1. For expression in wheat, the LbCpF1 enzyme was codon optimized and provided with maize Ubiquitin 1 promoter. Specific guide RNAs targeting alpha-, gamma-, omega-gliadins, and LMW glutenin subunits were designed and assembled in a single guide RNA module. The guide RNA module was provided with a common maize Ubiquitin 1 promoter. The genome-editing construct, with two expression cassettes one each for Cpf1 and guide RNAs, was delivered in wheat using pollen magnetofection. The initial results obtained from these experiments will be presented at the meeting.

publication date

  • July 2019