Figure 3.

Long-term epigenetic changes mediated by pathogens. A: Reprogramming of host cells by M. leprae. Mycobacterium leprae induces the Schwann cells it infects to differentiate into stem cell–like progenitor cells, which have the capacity to differentiate into multiple cell types, including smooth muscle or skeletal muscle cells. By inducing the reprogramming of Schwann cells, M. leprae regulates its own dissemination throughout different tissues. B: Transformation of host cells by T. parva. Theileria parva is, to date, the only organism known to induce continuous proliferation of the host cells it infects, which is directly tied to the division of this parasite as it hijacks the cell’s division machinery. Parasites induce transcriptional changes that lead to the suppression of apoptosis and up-regulation of proliferation genes. AT hook-binding proteins are also used to influence the transcriptome of host genes to promote survival of T. parva. C: Oncogenesis induced by chronic H. pylori infection. The bacterium H. pylori induces profound changes in transcription in its target tissue, the gastric epithelium. By secreting enzymes and virulence factors onto the surface of the epithelium and into cells, it induces damage to epithelial cells and a loss of cell polarity. Chronic exposure to H. pylori leads to altered transcription and DNA methylation, mirrored by changes in histone PTMs and eventual dysplasia and carcinogenesis.