Table 1.

Models and Mechanisms of Pro- and Anti-fibrotic Effects of γδ T Cells.

Model	Pro-fibrotic	Anti-fibrotic	Mechanism	Ref
BLM-induced murine lung fibrosis	+		IL-17 production by γδ T and TH17 cells	25
BLM-induced murine lung fibrosis		+	Production of CXCL10 by γδ T cells	29
BLM-induced murine lung fibrosis		+	IL-22 produced by γδ T cells	30
BLM-induced lung fibrosis in osteopontin-deficient mice		+	IFN-γ-producing γδ T cells	31
Melphalan-induced murine lung fibrosis	+		Induction of pro-inflammatory cytokines, e.g. IL-6 and IL-1β	34
Bacillus subtilis-induced murine lung fibrosis		+	IL-17A-expressing γδ T cells involvement in removal of offending organism	35
Bacillus subtilis-induced murine lung fibrosis		+	Production of IL-22 by γδ T cells	36
Bacillus subtilis-induced murine lung fibrosis		+	Immunoregulatory role of Vγ6/Vδ1(+) γδ T cell subset	35
Carbon tetrachloride (CCl4) murine model of liver fibrosis	+		TLR3 activation of IL-17 secretion by γδ T cells	39
Carbon tetrachloride (CCl4) murine model of liver fibrosis		+	Promotion of apoptosis of hepatic stellate cells by γδ T cells	40
Cryptosporidium parvum infection-induced murine liver periportal fibrosis	+		No mechanism presented	42
Rotavirus infection inducing murine biliary atresia	+		IL-17 production by γδ T cells	43
Schistosoma japonicum-induced murine liver fibrosis	+		IL-17 production by γδ T cells	44
In vitro experiments using human cells		+	Cell contact-dependent apoptosis of fibroblasts and reduction of collagen secretion byproducts of Vγ9Vδ2+T cells	18, 19
In vitro human experiments	+		Increased fibroblast proliferation and collagen production by supernatants of γδ T cells of systemic sclerosis patients	20, 21

BLM, Bleomycin; CXCL10, C-X-C motif chemokine 10; IL, interleukin; TH, T helper; TL, toll-like.