MR1 encompasses at least six allele groups with coding region alterations

Area of Science:

• Immunogenetics
• Molecular Biology
• Human Leukocyte Antigen (HLA) research

Background:

• Classical Human Leukocyte Antigen (HLA) class I genes are known for high polymorphism.
• The Mucosal Associated Invariant Natural Killer T (MR1) cell gene was previously assumed to have limited polymorphic positions.

Purpose of the Study:

• To investigate the extent of genetic variation within the MR1 gene.
• To develop and utilize a specific PCR assay for MR1 gene sequencing.

Main Methods:

• Development of a MR1-specific Polymerase Chain Reaction (PCR) assay.
• Sequencing of 56 DNA samples from cells with diverse HLA genotypes.
• Analysis of intronic single nucleotide polymorphisms (SNPs) and silent variants.

Main Results:

• Identification of six distinct allele groups encoding different MR1 proteins within the tested panel.
• The most frequent allele groups were MR1*01 (71%) and MR1*02 (25%).
• Discovery of numerous intronic SNPs and silent variants, with some samples exhibiting up to 15 heterozygous positions.

Conclusions:

• The MR1 gene exhibits marked genetic variation, contrary to previous assumptions.
• The identified polymorphisms and variants highlight the need for considering MR1 diversity in immunological studies.
• Further research is warranted to fully characterize MR1 polymorphism across diverse populations.