Impact of T cells on hematopoietic stem and progenitor cell function: Good guys or bad guys?

Table 1 Effects of (graft) treatments on hematopoietic stem cell transplantation

Treatment	Removed	Remaining	Effect
Complete T cell depletion	All T cells	N/A	GvHD ↓[8,14,44]
			Disease relapse ↑[8,9,44]
			Graft failure ↑[8,9,44]
			Immune reconstitution ↑[44]
Partial T cell depletion	CD45RA (TNV)	CD45RO (TMEM)	GvHD ↓[20,21,22]
	CD62L+ (TNV, TCM)1	CD62L- (TEM)1	Neutrophil engraftment ↑[22]
			Immune reconstitution ↑[20]
			Protective immunity ↑[21,22]
			Donor chimerism ↑[20,22]
Donor lymphocyte infusion	CD45RA (TNV)	CD45RO (TMEM)	GvHD ↓[26]
	CD62L+ (TNV, TCM)1	CD62L- (TEM)1	Tumor growth ↓[26]
			Engraftment ↑[26]
			Graft failure ↓[26]
			Immune reconstitution ↑[26]
			Protective immunity ↑[26,28]
			Donor chimerism ↑[26,27]

¹Signifies the murine equivalent of the human T cell subset described above. Here, we summarize the impact that either full or partial T cell depletion of an HSPC graft, or selective donor lymphocyte infusion, can have on the clinical outcome of a HSPC transplantation. Indicated are the T cell subsets that have either been removed or that remain, and the biological or clinical effects that have been reported following this treatment. N/A: Not available; HSPC: Hematopoietic stem and progenitor cell; GvHD: Graft-vs-host disease.