Entamoeba histolytica-Encoded Homolog of Macrophage Migration Inhibitory Factor Contributes to Mucosal Inflammation during Amebic Colitis.

Understanding the mechanisms by which Entamoeba histolytica drives gut inflammation is critical for the development of improved preventive and therapeutic strategies. E. histolytica encodes a homolog of the human cytokine macrophage migration inhibitory factor (MIF). Here, we investigated the role of E. histolytica MIF (EhMIF) during infection. We found that the concentration of fecal EhMIF correlated with the level of intestinal inflammation in persons with intestinal amebiasis. Mice treated with antibodies that specifically block EhMIF had reduced chemokine expression and neutrophil infiltration in the mucosa. In addition to antibody-mediated neutralization, we used a genetic approach to test the effect of EhMIF on mucosal inflammation. Mice infected with parasites overexpressing EhMIF had increased chemokine expression, neutrophil influx, and mucosal damage. Together, these results uncover a specific parasite protein that increases mucosal inflammation, expands our knowledge of host-parasite interaction during amebic colitis, and highlights a potential immunomodulatory target.