Macrophages fine-tune pupil shape during development.

Tissue macrophages, which are ubiquitously present innate immune cells, play versatile roles in development and organogenesis. During development, macrophages prune transient or unnecessary synapses in neuronal development, and prune blood vessels in vascular development, facilitating appropriate tissue remodeling. In the present study, we identified that macrophages contributed to the development of pupillary morphology. Csf1op/op mutant mice, in which ocular macrophages are nearly absent, exhibited abnormal pupillary edges, with abnormal protrusions of excess iris tissue into the pupillary space. Macrophages located near the pupillary edge engulfed pigmented debris, which likely consisted of unnecessary iris protrusions that emerge during smoothening of the pupillary edge. Indeed, pupillary edge macrophages phenotypically possessed some features of M2 macrophages, consistent with robust tissue engulfment and remodeling activities. Interestingly, protruding irises in Csf1op/op mice were only detected in gaps between regressing blood vessels. Taken together, our findings uncovered a new role for ocular macrophages, demonstrating that this cell population is important for iris pruning during development.

A case of cytomegalovirus esophagitis difficult to distinguish from Crohn's disease exacerbation.

Patients with Crohn's disease are at higher risk of opportunistic infection, especially if treated with immunosuppressive therapy. Cytomegalovirus has been reported to cause ulcerated lesions mainly in the lower gastrointestinal tract of inflammatory bowel disease patients. We herein report a rare case of Crohn's disease complicated with cytomegalovirus esophagitis, which was difficult to distinguish from exacerbation of Crohn's disease. Diagnostic values of clinical course, blood tests, endoscopic and histological examinations are limited but the present case was therapeutically diagnosed by antiviral therapy in combination with histological evidence of cytomegalovirus.