Full-Length Characterization of Novel HLA-DRB1 Alleles for Reference Database Submission

Area of Science:

• Immunogenetics
• Molecular Biology

Background:

• The IPD-IMGT/HLA database is critical for HLA genotyping.
• The HLA-DRB1 gene is challenging to fully characterize due to its length and variability, with only 16% of alleles fully sequenced in the database.

Purpose of the Study:

• To develop an improved protocol for full-length amplification and sequencing of HLA-DRB1 alleles.
• To enhance the data quality and completeness of the IPD-IMGT/HLA reference database.

Main Methods:

• Developed a long-range PCR amplification protocol for targeted HLA-DRB1 alleles.
• Combined long-read and short-read sequencing technologies for phased, error-corrected sequences.
• Utilized a dual redundant reference sequencing (DR2S) approach, particularly for resolving complex intron 1 repeat regions.

Main Results:

• Successfully characterized and submitted 384 full-length HLA-DRB1 sequences to the IPD-IMGT/HLA database.
• The DR2S approach ensures reference-grade quality sequences, crucial for resolving challenging genomic regions.
• Significantly increased the proportion of fully characterized HLA-DRB1 alleles.

Conclusions:

• The novel protocol effectively generates high-quality, phased, and error-corrected full-length HLA-DRB1 sequences.
• This advancement improves the integrity of the IPD-IMGT/HLA database, benefiting HLA genotyping laboratories.
• The DR2S method provides a robust solution for sequencing complex genetic regions within HLA alleles.