Immune cell differentiation and activation are associated with widespread DNA methylation changes; however, the causal relationship between these changes and their impact in shaping cell fate decisions still needs to be fully elucidated. Here, we conducted a genome-wide analysis to investigate the relationship between DNA methylation and gene expression at gene regulatory regions in human immune cells. By using CRISPR-dCas9-TET1 and -DNMT3A epigenome editing tools, we successfully established a cause-and-effect relationship between the DNA methylation levels of the promoter of the interleukin-1 receptor antagonist () gene and its expression. We observed that modifying the DNA methylation status of the promoter is sufficient to alter human myeloid cell fate and change the cellular response to inflammatory and pathogenic stimuli. Collectively, our findings demonstrate the potential of targeting specific DNA methylation events to directly modulate immune and inflammatory responses, providing a proof of principle for intervening in a broad range of inflammation-related diseases.