Figure 5

Astrogliosis and remyelination after intranasal administration of CNS-targeting Treg. Mice in three groups were given 1 × 10⁵ CAR Tregs, CD4⁺ Mock T cells or PBS alone by intranasal administration at the peak of EAE inflammation (15 days post-EAE immunization). Fifteen days post cell treatment the mice were killed and brain sections from each group (CAR Tregs, Mock CD4⁺ T cell and PBS) were analyzed for reactive astroglisosis using glial acidic fibrillary protein (GFAP) (A-I) and myelination using myelin basic protein (MBP) (J-R). GFAP was evaluated in olfactory bulb (A-C), corpus callosum (D-F), and cerebellum (G-I) of brain sagittal section from PBS, Mock CD4⁺ T cell and CAR Τreg-treated EAE mice. In the olfactory bulb of mice treated with Mock CD4⁺ T cells there was a strong staining for GFAP whereas this area in PBS-treated mice (A) and of CAR Treg-treated mice (C) exhibited a weak and moderate staining, respectively. There is an extremely weak staining in PBS-treated EAE mice, moderate staining in Mock CD4⁺ T cell-treated EAE mice and strong staining in CAR Treg-treated EAE mice for corpus callosum and cerebellum. MBP was evaluated in brain stem (J-L), hippocampus (M-O) and cerebellum (P-R) of brain sagittal sections in PBS, Mock CD4⁺ T cell and CAR Treg-treated EAE mice. In the brain stem and cerebellum of mice treated with CAR Tregs, there was a moderate staining for MBP (L, R) whereas the brain stem of Mock-treated mice (K,Q) and PBS-treated mice (J,P) exhibited a weak and strong staining, respectively. There is an extremely weak staining in PBS-treated EAE mice, a moderate staining in Mock CD4⁺ T cell-treated EAE mice and strong staining in CAR Treg-treated EAE mice for hippocampus. Original magnification 10×.