Research Article: Identification of HLA-A , HLA-B , and HLA-C triple homozygous and double homozygous donors: a path toward synthetic superdonor advanced therapeutic medicinal products
Abstract:
Human-induced pluripotent stem cells with broad immune compatibility are highly desirable for regenerative medicine applications. Human leukocyte antigen (HLA) class I homozygous cell sources are ideal for immune compatibility modeling. Here, we profile HLA-A , HLA-B , and HLA-C alleles in 3,496 Lithuanian donors genotyped at three-field resolution. The five most frequent alleles constitute 74.6% of HLA-A , 43.2% of HLA-B , and 59.2% of HLA-C , with HLA-A*02:01:01, HLA-B*07:02:01, and HLA-C*07:02:01 being the most common. Lithuanian allele frequencies closely resemble those of European-American and British populations. We identified 153 double homozygotes and 51 triple homozygotes for HLA-A , HLA-B , and HLA-C . Compatibility modeling showed that triple homozygous profiles match 60.5% of Lithuanians, 13.4% of the British population, and 7.4% of European-Americans. CRISPR-Cas9 guide RNA design yielded 54 candidates predicted to disrupt HLA-A or HLA-B while preserving HLA-C , producing edited profiles matching over 97.9% of Lithuanians, 95.7% of European-Americans, and 95.5% of the British population. Finally, we established 15 fibroblast lines from triple homozygotes as a bioresource for the derivation of human-induced pluripotent stem cells and immune compatibility studies.
Introduction:
Transplantation of allogeneic organs, tissues, and cells is constrained by immune matching between the graft and the host. Immune matching is mediated by the human leukocyte antigen (HLA) genes. These genes are clustered in a 3.7-Mbp locus on chromosome 6, are highly polymorphic, and their inheritance is reported as having intermediate linkage disequilibrium ( 1 , 2 ). The recent adoption of high-resolution haplotyping in clinics has improved the accuracy of immune matching for the more than 42,000 HLA alleles…
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