Dragotcytosis: elucidation of the mechanism for Cryptococcus neoformans macrophage-to-macrophage transfer

Q Dragotakes, MS Fu, A Casadevall - The Journal of Immunology, 2019 - journals.aai.org
The Journal of Immunology, 2019journals.aai.org
Cryptococcus neoformans is a pathogenic yeast capable of a unique and intriguing form of
cell-to-cell transfer between macrophage cells. The mechanism for cell-to-cell transfer is not
understood. In this study, we imaged mouse macrophages with CellTracker Green 5-
chloromethylfluorescein diacetate–labeled cytosol to ascertain whether cytosol was shared
between donor and acceptor macrophages. Analysis of several transfer events detected no
transfer of cytosol from donor-to-acceptor mouse macrophages. However, blocking Fc and …
Abstract
Cryptococcus neoformans is a pathogenic yeast capable of a unique and intriguing form of cell-to-cell transfer between macrophage cells. The mechanism for cell-to-cell transfer is not understood. In this study, we imaged mouse macrophages with CellTracker Green 5-chloromethylfluorescein diacetate–labeled cytosol to ascertain whether cytosol was shared between donor and acceptor macrophages. Analysis of several transfer events detected no transfer of cytosol from donor-to-acceptor mouse macrophages. However, blocking Fc and complement receptors resulted in a major diminution of cell-to-cell transfer events. The timing of cell-to-cell transfer (11.17 min) closely approximated the sum of phagocytosis (4.18 min) and exocytosis (6.71 min) times. We propose that macrophage cell-to-cell transfer represents a nonlytic exocytosis event, followed by phagocytosis into a macrophage that is in close proximity, and name this process Dragotcytosis (“Dragot” is a Greek surname meaning “sentinel”), as it represents sharing of a microbe between two sentinel cells of the innate immune system.
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