Figure 2.

Scheme of the regulatory cells present in MS lesions. The IL-10⁺ Treg/Treg ratio increases in the plaque of active and inactive lesions and at the rim of mixed active/inactive areas (Zandee et al., 2017). Perivascular CD138⁺CD38⁺ plasma cells act as a source of the anti-inflammatory cytokine IL-10, and they are mainly observed in active lesions (Machado-Santos et al., 2018). In terms of myeloid cells, the distribution of typical markers used to identify pro- or anti-inflammatory cells in demyelinating lesions reveals the presence of myeloid cells with an intermediate activation phenotype (CD40⁺/CD206⁺ cells) in active lesions (Vogel et al., 2013) and the coexistence of pro-inflammatory and regulatory myeloid cells at the rim of both mixed active/inactive and inactive lesions (Vogel et al., 2013; Jackle et al., 2020). However, anti-inflammatory myeloid cells are also observed in active lesions and at the rim of mixed active/inactive lesions (Miron et al., 2013). Legend: CD4⁺ T cell = CD4⁺ FoxP3⁻; Treg IL-10⁻ = CD4⁺ FoxP3⁺IL-10⁻; Treg IL-10⁺ = CD4⁺ FoxP3⁺ IL-10⁺; plasma B cell = CD138⁺CD38⁺; Mϕ pro-inflammatory = iNOS⁺ or CD40⁺ cells; Mϕ pro-/anti-inflammatory = CD40⁺CD206⁺ cells; Mϕ anti-inflammatory = CD206⁺ or CD163⁺ cells. Figure created with Biorender.com (accessed on 12 January 2022).