Are hemocytes the weapons of mass destruction of symbiont-induced light organ morphogenesis?
The search for evidence continues Tanya Koropatnick, Jennifer Kimbell, and Margaret McFall-Ngai Upon infection with Vibrio fischeri, the light organ of Euprymna scolopes undergoes a dramatic morphogenesis involving the loss of two ciliated epithelial fields, each containing two conspicuous ciliated appendages. During this process, the central sinuses of these appendages fill with host hemocytes. It has been shown that a key bacterial morphogen is peptidoglycan (PGN), which acts alone to trigger hemocyte infiltration, and works in synergy with LPS to trigger cell death and the regression of the epithelial fields. More recently the active fraction of V. fischeri PGN was identified to be identical to tracheal cytotoxin (TCT), a subunit released by Bordetella pertussis and Neisseria gonorrhoeae that induces inflammation and ciliated cell loss in mammalian epithelia exposed to these pathogens. As with PGN, TCT induced symbiotic levels of hemocyte infiltration into the appendage sinuses, fol
