title: Production of profibrotic cytokines by invariant NKT cells characterizes cirrhosis progression in chronic viral hepatitis.
abstract: Invariant (inv)NKT cells are a subset of autoreactive lymphocytes that recognize endogenous lipid ligands presented by CD1d, and are suspected to regulate the host response to cell stress and tissue damage via the prompt production of cytokines. We investigated invNKT cell response during the progression of chronic viral hepatitis caused by hepatitis B or C virus infection, a major human disease characterized by a diffused hepatic necroinflammation with scarring fibrotic reaction, which can progress toward cirrhosis and cancer. Ex vivo frequency and cytokine production were determined in circulating and intrahepatic invNKT cells from controls (healthy subjects or patients with nonviral benign or malignant focal liver damage and minimal inflammatory response) or chronic viral hepatitis patients without cirrhosis, with cirrhosis, or with cirrhosis and hepatocellular carcinoma. invNKT cells increase in chronically infected livers and undergo a substantial modification in their effector functions, consisting in the production of the type 2 profibrotic IL-4 and IL-13 cytokines, which characterizes the progression of hepatic fibrosis to cirrhosis. CD1d, nearly undetectable in noncirrhotic and control livers, is strongly expressed by APCs in cirrhotic ones. Furthermore, in vitro CD1d-dependent activation of invNKT cells from healthy donors elicits IL-4 and IL-13. Together, these findings show that invNKT cells respond to the progressive liver damage caused by chronic hepatitis virus infection, and suggest that these cells, possibly triggered by the recognition of CD1d associated with viral- or stress-induced lipid ligands, contribute to the pathogenesis of cirrhosis by expressing a set of cytokines involved in the progression of fibrosis.
authors.affiliation: Experimental Immunology Unit, Cancer Immunotherapy and Gene Therapy Program, DIBIT, H. San Raffaele Scientific Institute, Milano, Italy.
authors.forename: Claudia
authors.initials: C
authors.lastname: de Lalla
authors.forename: Grazia
authors.initials: G
authors.lastname: Galli
authors.forename: Luca
authors.initials: L
authors.lastname: Aldrighetti
authors.forename: Raffaella
authors.initials: R
authors.lastname: Romeo
authors.forename: Margherita
authors.initials: M
authors.lastname: Mariani
authors.forename: Antonella
authors.initials: A
authors.lastname: Monno
authors.forename: Sandra
authors.initials: S
authors.lastname: Nuti
authors.forename: Massimo
authors.initials: M
authors.lastname: Colombo
authors.forename: Francesco
authors.initials: F
authors.lastname: Callea
authors.forename: Steven A
authors.initials: SA
authors.lastname: Porcelli
authors.forename: Paola
authors.initials: P
authors.lastname: Panina-Bordignon
authors.forename: Sergio
authors.initials: S
authors.lastname: Abrignani
authors.forename: Giulia
authors.initials: G
authors.lastname: Casorati
authors.forename: Paolo
authors.initials: P
authors.lastname: Dellabona
mesh_terms: D000328:Adult; D000368:Aged; D000938:Antigen-Presenting Cells; D018949:Antigens, CD1 / Q000378:metabolism; D055610:Antigens, CD1d; D016207:Cytokines / Q000378:metabolism*; D005260:Female; D006525:Hepatitis, Viral, Human / Q000378:metabolism*; D006801:Humans; D007694:Killer Cells, Natural / Q000378:metabolism*; D008103:Liver Cirrhosis / Q000378:metabolism* / Q000821:virology; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000378:metabolism*
chemical_list: D018949:Antigens, CD1; D055610:Antigens, CD1d; C526877:CD1D protein, human; D016207:Cytokines