Adaptive immune response during hepatitis C virus infection

Table 1 Summary of the phenotypic and functional features of hepatitis C virus-specific CD8⁺ cells according to hepatitis C virus control directly ex vivo and after different in vitro treatments

	PD-1ex vivo	CD127ex vivo	Mcl-1ex vivo/after TCR triggering	Bimex vivo/after TCR triggering	Expansion1	Expansion(αPD-L1)2	Expansion(zVAD-fmk)3	Expansion(αPD-L1 andαCTLA-4)4	Expansion(αPD-L1 andα41BB)5
Persistent infection
PBMC	(+)	(-)	Low/low	Low/high	Impaired	Restored	Restored	Restored	Restored
IHMC	(++)	(-)			Impaired			Restored	Impaired
Resolved infection
PBMC	(-)	(++)	High/low	Low/low	Positive	Positive	Positive

(-) Low expression; (+) Intermediate expression; (++) High expression. Expansion: proliferation after specific in vitro challenge

¹without any other treatment;

²in presence of anti-PD-L1 mAb;

³blocking apoptosis after treatment with z-VAD-fmk, in presence of anti-PD-L1 mAb and anti-CTLA4 mAb⁴ and adding anti-PD-L1 mAb plus stimulating anti-41BB mAb⁵. PBMC: Peripheral blood mononuclear cells; IHMC: Intrahepatic mononuclear cells[47,48,75,76,78,105]. Bim: Bcl-2-interacting mediator; CTLA4: Cytotoxic T-Lymphocyte Antigen 4.