Fig. 7.

Immune cell infiltration in the PNS of transgenic ALS mice promotes Schwann cells (SCs) proliferation and axonal maintenance. Schematic representation of the PNS of C57SOD1^G93A mice and 129SvSOD1^G93A mice during disease progression. a In the C57SOD1 ^G93A mice, the activation of MHCI, autophagocytic SCs, and C3 byproducts leads to the recruitment and interaction of CD8⁺ T cells and macrophages at the site of injury. CD8⁺ T cells and macrophage coordinated activity potentiates the rate of degradation of defective SCs (and myelin debris) in order to stimulate the de-differentiation and proliferation of SCs and, finally, the remyelination of motor axons and NMJs. b In the 129SvSOD1^G93A mice, the lower phagocytic activity of SCs/macrophage and the lack of CD8⁺ T cell infiltration result in less removal of defective SCs in addition to reduced SCs de-differentiation/proliferation which lead to earlier muscle denervation