This chapter overviews roles of DNA methylation in inflammatory cell biology with the focuses on lymphocytes and macrophages/monocytes in lung diseases, although the molecular mechanisms by which target genes are methylated and regulated in lung diseases remain unclear. Most of epigenetic studies on DNA methylation of target genes in lung diseases mainly demonstrated the correlation of DNA methylation of target genes with the levels of other corresponding factors, with the specificity of clinical phenomes, and with the severity of lung diseases. There is an urgent need to identify and validate the specificity and regulatory mechanisms of inflammatory cell epigenetics in depth. The epigenetic heterogeneity among different subsets of T cells and among promoters or non-promoters of target genes should be furthermore clarified in acute or chronic lung diseases and cancers. The hyper/hypo-methylation and modifications of chromosol and extrachromosomal DNA may result in alternations in proteins within inflammatory cells, which can be identified as disease-specific biomarkers and therapeutic targets.
Keywords: DNA methylation; Epigenetics; Inflammatory cells; Lung disease.