AUTHOR=Klussmeier Anja , Massalski Carolin , Putke Kathrin , Schäfer Gesine , Sauter Jürgen , Schefzyk Daniel , Pruschke Jens , Hofmann Jan , Fürst Daniel , Carapito Raphael , Bahram Seiamak , Schmidt Alexander H. , Lange Vinzenz 

TITLE=High-Throughput MICA/B Genotyping of Over Two Million Samples: Workflow and Allele Frequencies

JOURNAL=Frontiers in Immunology

VOLUME=11

YEAR=2020

URL=https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2020.00314

DOI=10.3389/fimmu.2020.00314

ISSN=1664-3224

ABSTRACT=<p>MICA and MICB are ligands of the NKG2D receptor and thereby influence NK and T cell activity. <italic>MICA/B</italic> gene polymorphisms, expression levels and the amount of soluble MICA/B in the serum have been linked to autoimmune diseases, infections, and cancer. In hematopoietic stem cell transplantation, <italic>MICA</italic> matching between donor and patient has been correlated with reduced acute and chronic graft-vs.-host disease and improved survival. Hence, we developed an extremely cost-efficient high-throughput workflow for genotyping <italic>MICA/B</italic> for newly registered potential stem cell donors. Since mid-2017, we have genotyped over two million samples using NGS amplicon sequencing for <italic>MICA/B</italic> exons 2–5. In donors of German origin, <italic>MICA</italic>*<italic>008</italic> is the most common <italic>MICA</italic> allele with a frequency of 42.3%. It is followed by <italic>MICA</italic>*<italic>002</italic> (11.7%) and <italic>MICA</italic>*<italic>009</italic> (8.8%). The three most common <italic>MICB</italic> alleles are <italic>MICB</italic>*<italic>005</italic> (43.9%), <italic>MICB</italic>*<italic>004</italic> (21.7%), and <italic>MICB</italic>*<italic>002</italic> (18.9%). In general, <italic>MICB</italic> is less diverse than <italic>MICA</italic> and only 6 alleles, instead of 15, account for a cumulative allele frequency of 99.5%. In 0.5% of the samples we observed at least one allele of <italic>MICA</italic> or <italic>MICB</italic> which has so far not been reported to the IPD/IMGT-HLA database. By providing <italic>MICA/B</italic> typed voluntary donors, clinicians become empowered to include <italic>MICA/B</italic> into their donor selection process to further improve unrelated hematopoietic stem cell transplantation.</p>