Fig. 8.

Mast cells stain positive for Toluidine blue, NSE, GzmB, and C-kit in mouse choroid/sclera and positive for GzmB in human. A Representative image showing the presence of toluidine blue positive mast cells (in pink) in an albino mouse choroidal wholemount at 100X magnification. B Representative image revealing mast cells in the process of degranulation in an albino mouse choroidal wholemount. C Image showing the presence of NSE positive cells in the choroid of a mouse choroid cross section at 40X magnification. Red color represents NSE, a marker of mast cells and macrophages and the blue color is DAPI [43, 44]. Arrows point to NSE label that is from Mast cells. D Showcases a granular GzmB positive cell in a mouse choroid/sclera cross-section. Arrow points to an example cell at 20X magnification. E Representative image of a mast cell positive for GzmB in the upper choroid in mouse. F–H Double label image of C-kit (green) and GzmB (red) in mouse choroid wholemount showing mast cells at 20X magnification. While the majority of the cells co-label GzmB and C-kit, the arrow points to a C-kit only cell, suggesting different populations of mast cells based on types of proteases. Asterisk highlights extracellular GzmB in choroid. I Human choroidal wholemount pie piece labelled with GzmB showing relative distribution to choroidal vasculature. J–K Representative image showcasing non-dengranulated and degranulating mast cells in Human choroidal wholemount. Scale bar in A, B, E, J–K is 10um. Scale bar in C, D, F–H is 20um. Scale bar in I is 1 mm