Complex sentence: While the DQ2.2 heterodimer cannot effectively present α-2 gliadin, it can present other gliadins, and 1% of coeliacs it is certain that DQ2.2 confers adaptive immunity to gliadin permitting coeliac disease.
Split into simpler sentences: While the DQ2.2 heterodimer cannot effectively present α-2 gliadin, it can present other gliadins. In at least 1% of coeliacs DQ2.2 confers adaptive immunity to gliadin permitting coeliac disease.