Fig. 3: MPXV spreads through cell-to-cell contact.
From: Monkeypox virus spreads from cell-to-cell and leads to neuronal death in human neural organoids
a Representative transmission electron microscopy images of 95 days old hNOs at 10 days p.i. exposed to a clade IIb MPXV isolate at an MOI of 0.1 TCID50/cell. MPXV particles were observed localizing to neurites in infected tissue. Black arrowheads indicate exemplary virion-harboring neurites. Scale bar, 0.5 µm. b Representative image of detection by immunofluorescence of MPXV signal within neural filaments of interconnected, distinct cells. DAPI, blue; MPXV, green. Scale bar, 10 µm. c Representative micrographs of 95-day-old hNOs infected with a clade IIb MPXV isolate, showing the filaments connecting MPXV antigen-positive cells and displaying diverse TUJ1 and F-actin patterns. Some filaments were observed showing expression of both markers (yellow arrowheads), indicative of their neuritic nature, others lacked TUJ1 signal, indicative of TNTs (blue arrowheads). DAPI, blue; MPXV, green; TUJ1, orange; F-actin, cyan. Scale bar, 10 µm. d Representative micrographs of 2D cultured forebrain neurons exposed to an mNG-expressing clade IIb MPXV reporter construct, showing viral dissemination between interconnected neighboring cells. White arrowheads indicate mNG-harboring neurites. Images were taken at 40-min intervals, time represented in minutes. Scale bar, 100 µm. e Cell-associated and released infectious MPXV 2 to 14 days p.i. of 70–95 days old hNOs infected with a clade IIb isolate at a rate of 0.1 TCID50/cell. Each symbol represents an individual organoid (n = 7–8 independent organoid batches). Unpaired, two-tailed student’s t-test was applied to compare groups. M indicates mock. f Cell-associated and released MPXV titers in 2D cultured NPCs challenged with a clade IIb MPXV isolate at a rate of 0.01 TCID50/cell. Each symbol represents one NPC batch (n = 3 independent NPC batches). Unpaired, two-tailed student’s t-test was applied to compare groups. M indicates mock. g Released and cell-associated infectious MPXV in 2D cultured forebrain neurons exposed to a clade IIb MPXV isolate at a rate of 0.01 TCID50/cell. Each symbol represents one neuron batch (n = 4 independent neuron batches). Unpaired, two-tailed student’s t-test was applied to compare groups. M indicates mock. Dashed line indicates the detection limit of the assay. Source data are provided as a Source Data file.
