Epigenetic Modulation of Immunity: Mechanisms, Implications, and Emerging Therapeutic Horizons; a Step Toward Epigenetics to Precision.

Epigenetic regulation plays a central role in immune cell development, specialization, and memory formation by dynamically modifying DNA, histones, and RNA. These processes enable adaptation to environmental cues, precise pathogen responses, and maintenance of immune tolerance, while their disruption contributes to autoimmune, inflammatory, and cancer pathogenesis. DNA methylation, histone modifications, and noncoding RNA regulation shape the lineage and activation states of T cells, B cells, macrophages, and natural killer (NK) cells, with specific alterations linked to diseases, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). Emerging insights also highlight roles for RNA modifications and exosome-mediated RNA transfer in immune activation, trained immunity, and antigen presentation. Advances in single-cell epigenomics, CRISPR-based editing, and RNA sequencing are driving the development of targeted therapies-such as DNA methyltransferase (DNMT) inhibitors, histone deacetylase (HDAC) inhibitors, RNA-based interventions, and exosome delivery systems-that aim to reprogram immune responses. Understanding immune cell epigenetics paves the way for precision immunotherapies tailored to patient-specific profiles, offering highly specific, effective treatments with minimal immune suppression.