Figure 8. Detection of CnMV particles in infected mouse blood.

Mice were intravenously injected with 5×10⁶ cryptococcal cells of either strain JBO2 (A) or strain C1186 (B). After 16 hr, a drop of blood was collected from either the eyes or the tail vein, and was plated onto the glass slide. Red blood cells were observed under the light microscope (left panel) and green CnMV particles (indicated by yellow arrows) could be observed in the immunofluorescence image of JBO2 sample (A: right panel). (C) A model of the putative role of disseminated CnMVs to facilitate C. neoformans traversal through the blood-brain barrier is shown. The middle section shows the monolayer of human brain microvascular endothelial cells (HBMEC) (light pink cells). C. neoformans cells (green) may continuously secret extracellular vesicles CnMVs into the blood stream. Intact CnMVs (green dots) and/or already-lysed components of the CnMV’s (e.g., green sector area) contact the HBMEC and exert some profound effects on the surface of HBMEC (dark pink bar), a pre-adhesion step. Subsequently, the active surface is facilitated for C. neoformans binding with the HBMEC, the adhesions step.