Figure 5.

SIINFEKL-prestimulated cytotoxic OT-I T cells invade brain tissue and cause damage of myelinated axons. Spot analysis from confocal time-lapse imaging revealed that SIINFEKL-prestimulated CD8⁺ OT-I T cells invaded ODC-OVA × PLP-GFP slices to a significantly greater extent than nonactivated or control peptide-prestimulated CD8⁺ OT-I T cells (C). Extensive disruption and irregularities of both myelin (green) and axons (cyan) in ODC-OVA × PLP-GFP brain slices were observed after incubation with SIINFEKL-prestimulated CD8⁺ OT-I T cells (A) in contrast to well-maintained structures in slices incubated with nonactivated CD8⁺ OT-I T cells (B). Quantification of axonal damage confirms that neurofilament was significantly injured in ODC-OVA × PLP-GFP brain slices incubated with SIINFEKL-prestimulated CD8⁺ OT-I T cells when compared with controls (D). Results are expressed as percentage of intact neurofilament compared with ODC-OVA × PLP-GFP brain slices incubated with nonactivated CD8⁺ OT-I T cells. Values are ± mean SEM, n = 3; for P value generation one-way analysis of variance followed by Bonferroni posttest was used to compare among groups (C and D). Scale bars equal 200 μm in A and B.