The role of DNA methylation in the regulation of HLA expression

DNA methylation plays a critical role in the regulation of gene expression in the human leukocyte antigen (HLA) system which is a key component of immune function. This article reviews the molecular mechanisms by which DNA methylation influences HLA gene regulation, highlighting its impact on their antigen presentation and immune tolerance functions. We describe how methylation patterns vary in HLA class I and II genes, affecting their expression in a tissue- and allele-specific manner. In addition, we examine the interplay of DNA methylation in shaping immune responses. A focus is on the role of methylation in immune-mediated, namely autoimmune diseases, where aberrant epigenetic modifications at HLA loci contribute to disease susceptibility and progression. We also explore how single nucleotide polymorphisms (SNPs) within CpG sites can alter methylation patterns and gene expression, providing insights into genetic-epigenetic interactions. These findings may contribute to the development of new diagnostic and therapeutic strategies for immune-mediated diseases.