Role of gamma-delta T cells in liver inflammation and fibrosis

Table 1 Role of gamma-delta T cells in human and experimental liver disease

Species	Liver disease	TCR usage	Cytokine production	Other markers	Effector function(s)	Ref.
Protective functions of γδ T cells
Mouse	Concanavalin A-induced hepatitis	Vγ4	IL-17		γδ T cells inhibit NKT cell function	[20]
Mouse	Experimental fibrosis	Vγ4?	IL-17, IL-22	CCR6, CD95L	γδ T cells induce stellate cell apoptosis and limit collagen production	[47]
Mouse	Listeria monocytogenes infection	Vγ4	IL-10		γδ T cells downregulate CD8+ T cell effector function	[39]
		Vγ4/Vγ6	IL-17		γδ T cells are protective during early infection	[24]
Human	Liver metastasis of colon cancer	Vδ1	IFNγ, TNFα, IL-2	CD56, CD161	hepatic γδ T cells are cytotoxic against tumor cell lines in culture	[17]
Human	Pediatric tumor cell culture	Vγ9Vδ2	?		γδ T cells are cytotoxic against hepatoma cells in culture	[18]
Mouse	Adenoviral infection	Vγ4	IL-17		γδ T cells are critical for establishment of functional adaptive immune responses	[21]
Pathogenic functions of γδ T cells
Mouse	Schistosoma japonicum infection	?	IL-17		γδ T cells contribute to immune-mediated pathology	[40]
Mouse	Adenoviral infection	?	IFN-γ	CXCR3	γδ T cells contribute to hepatocyte apoptosis via FasL engagement and recruitment of cytotoxic T cells	[37]
Mouse	MHV infection	?	TNF-α, IFN-γ, IL-17, IL-2	CD69, CD44	γδ T cells induce hepatocyte apoptosis via TNF-α-signaling	[38]
Human	HCV infection	Vδ1	IFN-γ	HLA-DR, CD95, CD45-RO	Activated γδ T cells contribute to HCV-mediated immunopathology	[19]

γδT cells: Gamma-delta T cells; IFN: Interferon; IL: Interleukin; TNF: Tumor necrosis factor; MHV: Mouse hepatitis virus; HCV: Hepatitis C virus.