Table 2.

Immunologic interplay between astrocytes and oligodendrocytes.

	Detrimental	Beneficial	References
Astrocyte Mediator	Impact on Oligodendrocytes
TNF-α	Induces demyelination and oligodendrocyte necrosis	Induces PDGF, and LIF on astrocytes which enhances OPC survival and differentiation	[3,108,109,110,111,112]
IL-1β	Induces oligodendrocyte apoptosis and hypomyelination		[102]
IFN-γ	Reversibly reduces OPC proliferation	Limits inflammation, limits Th17 activation, limits IL-1β signalling, protects oligodendrocytes from endoplasmic reticulum stress	[106,113,114,115]
FGF-2	Induces loss of myelin and myelin-producing oligodendrocytes	Induces proliferation of OPCs	[4,116]
BMP	BMPs induce OPC differentiation into the astrocyte lineage		[21,117]
CNTF		Induces proliferation and differentiation of OPCs	[21,105]
IGF-1		Induces OPC differentiation	[21,107,118]
Oligodendrocyte Mediator	Impact on Astrocytes
CCL2		Reduces IL-6 expression in astrocytes, leading to a less inflammatory environment	[92,119,120]
CXCL10	Induces CXCR3 receptor expression		[119,121]
IL-17	Induces GFAP, IL-1β, and VEGF, reduces BBB integrity Induces astrogliosis		[89,122]
IL-1β	Induces IL-1β and NF-κB, and P2X7 receptor.		[90,92,123,124]
GM-CSF		Inhibits glial scar formation. Induces proliferation, and migration of astrocytes	[93,125]

Abbreviations: BMP, bone morphogenic protein, CNTF, ciliary neurotrophic factor; FGF, Fibroblast growth factor; IFN, interferon; IGF, insulin-like growth factor; LIF, leukaemia inhibitory factor; OPC, oligodendrocyte precursor cell; PDGF, Platelet-derived growth factor; TNF, tumour necrosis factor.