Expanded Allelic Diversity of Non-Classical HLA Class I and MIC Loci Identified Using Full-Gene Hybrid Capture-Based...

Area of Science:

• Immunogenetics
• Molecular Biology
• Human Genetics

Background:

• Non-classical Human Leukocyte Antigen (HLA) Class I genes (HLA-E, -F, -G, -H) and MHC-related genes (MICA, MICB) are crucial for Natural Killer (NK) cell function and immune tolerance.
• The allelic diversity of these important genes is not fully understood, limiting comprehensive immunogenetic profiling.

Purpose of the Study:

• To identify novel alleles within non-classical HLA Class I and MHC-related genes.
• To characterize the allelic diversity of HLA-E, -F, -G, -H, MICA, and MICB in a healthy US population.

Main Methods:

• Capture-enriched full-gene sequencing was performed on DNA from 943 healthy US transplant donors.
• Novel alleles were identified by comparing sequencing data to known allele databases.

Main Results:

• Twenty-six novel alleles were identified across HLA-E (2), HLA-F (6), HLA-G (4), HLA-H (5), MICA (3), and MICB (6).
• Each novel allele was found in a single individual and differed by a single nucleotide polymorphism (SNP) in the coding region.
• A recently described HLA-G allele (HLA-G*01:01:33) was confirmed and found to co-segregate with a conserved haplotype (HLA-A*34:01:01, HLA-F*01:01:01, HLA-H*02:27).

Conclusions:

• The study significantly expands the known catalogue of non-classical HLA and MIC alleles.
• Capture-enriched full-gene sequencing is a powerful method for detailed immunogenetic characterization.
• The findings contribute to a better understanding of immune diversity and its implications for transplantation and tolerance.