Figure 1.

Histopathology of the peripheral nervous system in affected H3 TKO mice. (a–c) The sciatic nerves from TKO (a), B2L TKO (b), and disease-affected H3 TKO mice (c) were stained with toluidine blue. (d) Electron micrograph of the same H3 TKO sciatic nerve shown in c, showing accumulation of lymphoid cells (arrowheads) around macrophages containing degenerated myelin sheaths within phagosomes (arrows). (e–h) Double immunofluorescence histochemistry of the sciatic nerve from an affected H3 TKO mouse shows infiltration of many CD11b⁺ cells (e and f, green) and CD4⁺ cells (e, red), and small numbers of NK1.1⁺ cells (f, red). Immunoreactivity for CD4 (g and h, green) is colocalized with that for αβ TCR (g, red), but not with that for NK1.1 (h, red). (i–m) The presence or absence of CD11b⁺ macrophages (green) and CD4⁺ T cells (red) in the facial (i), trigeminal (j), vagus (k), and optic (l) nerves, and in the spinal cord (SC), and dorsal (DR) and ventral (VR) roots of the spinal nerve (m) of affected H3 TKO mice. All peripheral nerve types sustain massive infiltration of CD4⁺ T cells and CD11b⁺ macrophages (i–k and m, DR and VR), whereas the central nervous tissues are intact (l and m, SC). Each fluorescence image is superimposed on the phase-contact image of the same field (e, f, and m). The scale bar represents 40 μm in a–c, 5 μm in d, 50 μm in e, f, and i–l, 25 μm in g and h, and 80 μm in m.