Fig. 4

ZIKV infection injures CNS myelin and axons in Ifnar1 knockout mouse myelinating cultures. Antibody AA3 to PLP/DM20 labels oligodendrocyte cell bodies whilst both AA3 and anti-MBP label myelin-like sheaths at 18 (a, b, d) and 24 days in vitro (DIV) (e, f, h, i, j and l). Antibody SMI31 labels phosphorylated heavy and medium chain neurofilament at 18 (c) and 24 DIV (g, k). h, l Both myelin and axons are diminished in ZIKV infected cultures compared to mock infected cultures. Most of the remaining myelin in ZIKV infected cultures appears fragmented (inset in i versus inset in e). In contrast to controls, ZIKV infected cultures contain many neuronal cell bodies filled with phosphorylated neurofilament (yellow arrow k, l). d, h and l Deterioration of neurites (axons and dendrites) in ZIKV infected cultures can also be visualized using antibodies to β tubulin 3 (microtubules) and non-phosphorylated neurofilament (SMI32; compare n and p to m and o). In n, only a few neurites (white arrows) are visible and, whilst normal-appearing neuronal cell bodies are labelled in mock infected cultures (yellow arrows in m), those in the infected cultures appear abnormal (yellow arrows in n). q, r Graphs showing mean percentage of pixels that are PLP/DM20 or MBP positive per area of interest; bars represent mean of 3 independent experiments ± SD. Bars: 50 μm,​ * p ≤ 0.05