Table 1.

The immune players influenced by the various stem cell types at the injury microenvironment after transplantation in SCI.

Type of cells	Immune players influenced at injury milieu	Effects on recovery	Citations
Neural stem cells (NSCs)	FGF2 HGF CD133+/CD34−/CD45− Neurogenin-2 GSI	Facilitatory Facilitatory Facilitatory Facilitatory Tumor inhibition	[55] [61] [62] [67] [72]
Schwann cells (SCs)	p75 GFAP S100 L1 N-CAM NGF BDNF GDNF CNTF IL-10 Fibronectin Laminin	Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory	[3, 74] [3, 74] [3, 74] [3, 74] [3, 74] [78–81] [78–81] [78–81] [78–81] [86–88] [74] [74]
Olfactory ensheathing cells (OECs)	p75 GFAP S100 L1 N-CAM Fibronectin Laminin	Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory	[3, 74] [3, 74] [3, 74] [3, 74] [3, 74] [74] [74]
Ependymal cells	EGF FGF2	Facilitatory Facilitatory	[107] [107]
Human central nervous system stem cell (HuCNS-SC)	Further studies needed	Facilitatory	[109]
Erythropoietin-releasing neural precursors cells (Er-NPCs)	Macrophages rhEPO 5-TH GAP43 BDNF NGF β-Tubulin III MAP-2	Inhibitory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory	[31, 112] [117] [31, 116, 117] [31, 118–120] [116, 122, 123] [116, 122, 123] [31] [31]
Mesenchymal stem cells (MSCs)	5-HT GAP43 BDNF VEGF FGF2 MAP-2 GABA-A BNP TGF-β	Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory Facilitatory	[137] [128, 147] [4, 148] [4, 148] [4, 148] [4, 151] [4, 151] [4, 152, 153] [4, 161, 162]
Induced pluripotent stem cells (iPSCs)	GSI HSVtk GCV	Tumor inhibition Tumor inhibition Tumor inhibition	[1] [1] [1]
Umbilical cord blood cells (UCBCs)	CD34+/CD45− CD133+	Facilitatory Facilitatory	[3] [3]