Biliary Antigens Research Articles

Bile from Patients with Primary Sclerosing Cholangitis Contains Mucosal-Associated Invariant T-Cell Antigens

Primary sclerosing cholangitis (PSC) is associated with altered microbiota of the gut and bile. Mucosal-associated invariant T (MAIT) cells, enriched in human liver, uniquely recognize microbial-derived metabolites. This study aimed to determine whether bile from patients with PSC contains antigens activating MAIT cells. Bile was collected at the time of liver transplantation from patients with PSC (n=28). The bile samples were either directly incubated with peripheral blood mononuclear cells from healthy donors or with antigen-presenting cells followed by co-culture with peripheral blood mononuclear cells. MAIT cell activation was assessed by flow cytometry. An anti-MR1 antibody was used to determine whether the activation was major histocompatibility complex class I-related protein (MR1) restricted. Biliary microbiota profiles were generated using 16S rRNA amplicon sequencing, and the abundance of the bacterial gene ribD was predicted. Eight of 28 bile samples could activate MAIT cells. This activation was partly MR1-dependent in five of eight bile samples. Microbial DNA was detected in 15 of 28 bile samples, including the five bile samples leading to MR1-dependent activation. A higher abundance of the ribD gene expression in the group of bile samples that could activate MAIT cells was predicted on the basis of the 16S sequencing. In co-culture experiments, cholangiocytes could take up and present biliary antigens to MAIT cells. These findings suggest a pathophysiological pathway in PSC connecting the immune system and the microbiome.

Nonsuppurative cholangitis is induced in neonatally thymectomized mice: A possible animal model for primary biliary cirrhosis

Neonatally thymectomized mice are unique in that they are prone to organ-specific autoimmune diseases. We investigated whether autoimmune cholangitis could be induced in these mice when they were immunized with biliary antigens. Neonatally thymectomized A/J mice were immunized with porcine intrahepatic bile duct epithelial cells (group 1), porcine gallbladder epithelial cells (group 2), porcine splenocytes (group 3) or Freund's adjuvant (group 4). Nonthymectomized mice were immunized with bile duct epithelial cells (group 5) or Freund's adjuvant (group 6). The cell suspensions were injected intraperitoneally with Freund's adjuvant once a week for 8 wk. In group 1 varying amounts of mononuclear cells infiltrated around the bile duct in 14 of 22 mice, whereas little or no accumulation was noted in other groups. Ultrastructural observations revealed that the inflammatory cells consisted of lymphocytes, plasma cells and macrophages. The bile duct showed degenerative changes and some lymphocytes infiltrated between bile duct epithelial cells. An immunohistochemical study showed that the accumulated lymphocytes consisted of CD4+ and CD8+ T cells, as well as B cells. Both major histocompatibility complex class I and class II antigens were expressed on bile duct epithelial cells. Antimitochondrial antibody was demonstrated in some mice in groups 1 (9 of 17), 2 (2 of 3) and 5 (4 of 5) by immunofluorescence; the antibody reacted with the 68, 52 and 47 kD polypeptides of the pyruvate dehydrogenase complex on Western blotting. These findings suggest that autoimmune cholangitis can be induced in neonatally thymectomized mice stimulated with biliary antigens and that these mice could be a suitable animal model for primary biliary cirrhosis.

Nonsuppurative cholangitis is induced in neonatally thymectomized mice: A possible animal model for primary biliary cirrhosis

Neonatally thymectomized mice are unique in that they are prone to organ-specific autoimmune diseases. We investigated whether autoimmune cholangitis could be induced in these mice when they were immunized with biliary antigens. Neonatally thymectomized A J mice were immunized with porcine intrahepatic bile duct epithelial cells (group 1), porcine intrahepatic epithelial cells (group 2), porcine splenocytes (group 3) or Freund's adjuvant (group 4). Nonthymectomized mice were immunized with bile duct epithelial cells (group 5) or Freund's adjuvant (group 6). The cell suspensions were injected intraperitoneally with Freund's adjuvant once a week for 8 wk. In group 1 varying amounts of mononuclear cells infiltrated around the bile duct in 14 of 22 mice, whereas little or no accumulation was noted in other groups. Ultrastructural observations revealed that the inflammatory cells consisted of lymphocytes, plasma cells and macrophages. The bile duct showed degenerative changes and some lymphocytes infiltrated between bile duct epithelial cells. An immunohistochemical study showed that the accumulated lymphocytes consisted of CD4 + and CD8 + T cells, as well as B cells. Both major histocompatibility complex class I and class II antigens were expressed on bile duct epithelial cells. Antimitochondrial antibody was demonstrated in some mice in groups 1 (9 of 17), 2 (2 of 3) and 5 (4 of 5) by immunofluorescence; the antibody reacted with the 68, 52 and 47 kD polypeptides of the pyruvate dehydrogenase complex on Western blotting. These findings suggest that autoimmune cholangitis can be induced in neonatally thymectomized mice stimulated with biliary antigens and that these mice could be a suitable animal model for primary biliary cirrhosis.

THE SYNDROME OF DISAPPEARING INTRAHEPATIC BILE DUCTS

Diseases with disappearing intrahepatic bile ducts may be developmental, immunological, infective, vascular, or chemical in origin. The immunological group includes primary biliary cirrhosis, graft-versus-host disease, and sarcoidosis. HLA class 2 antigens are displayed on the bileducts and recognition of biliary antigens by cytotoxic T-cells leads to destruction of interlobular ducts. Primary sclerosing cholangitis is associated with immunological features, but the hepatic histology is not that of immunological duct disease. The association with immunodeficiency syndromes, and the finding that secondary sclerosing cholangitis may occur in patients with the acquired immunodeficiency syndrome who are infected with cytomegalovirus, suggest that primary sclerosing cholangitis might be infective in origin. In bacterial cholangitis there is contiguity between the biliary system and the intestinal tract and usually, but not necessarily, partial biliary obstruction. Interference with the hepatic arterial supply to the bileducts leads to vascular cholangitis. Chemical cholangitis follows injection of scolicidal agents into the biliary tree. Diseases with disappearing bileducts have a long natural history and hepatocellular failure occurs late. In the late stages hepatic transplantation gives good results.

Detection of biliary tract antigens using murine monoclonal antibodies (Mab's)

Detection of biliary tract antigens using murine monoclonal antibodies (Mab's)

Relationship between primary biliary cirrhosis and chronic graft versus host disease: investigation of histocompatibility (HLA) antigenic determinants in biliary tract antigens.

1. According to a recent hypothesis, based on similarities between chronic graft versus host disease and primary biliary cirrhosis (PBC), immune reactions against histocompatibility (HLA) antigens may be responsible for the bile duct damage and extrahepatic lesions of PBC. 2. Previous studies have demonstrated autoimmune reactions in PBC against normal human biliary tract antigens. To equate these findings with the above hypothesis, it has been suggested that the biliary antigens are related to the HLA system and, in the present study, this possibility has been investigated by: (a) using preparations of the biliary antigens to inhibit the lymphocytotoxic activity of standard HLA-typing sera against normal lymphocytes, and (b) employing guinea-pig antisera raised against the biliary antigens as 'typing reagents' in the lymphocytotoxicity test to determine whether these antisera recognize HLA components on the surfaces of normal lymphocytes. 3. No inhibition by the biliary antigens of the reaction of two standard typing sera against T-and B-lymphocytes from two normal healthy donors (covering nine HLA-A, -B, -C and three HLA-DR loci antigens) was observed. Conversely, the guinea-pig antisera showed no reaction against these lymphocytes. 4. The results suggest that the biliary tract antigens are probably not related to 'common' antigenic determinants associated with the HLA system.

Differential in vitro immune responses to biliary tract antigens in primary biliary cirrhosis and chronic active hepatitis

Cellular immune reactions against normal biliary tract antigens have been investigated in 21 patients with primary biliary cirrhosis (PBC) and 18 with chronic active hepatitis (CAH) using the leucocyte migration inhibition test with partially purified antigens from normal human gall-bladder bile. Four antigen fractions, containing (either separately or together) three previously-described biliary antigens, were employed: (1) Antigen I; (2) Canalicular antigen; (3) Canalicular and Ductular antigens; (4) All three antigens. Seventeen (81%) of the PBC patients showed migration inhibition with all four fractions. Five (28%) of the CAH patients showed inhibition with three fractions but none exhibited sensitization to the fraction containing only the antigen derived from the bile canalicular portion of the hepatocyte membrane. In experiments with purified lymphocyte sub-populations from PBC patients, leucocyte migration inhibitory factor production was shown to be a function of T-lymphocytes. The antigenic selectivity with respect to the responses in CAH patients suggests that sensitization to biliary tract antigens is probably not a secondary phenomenon resulting from "unmasking" of antigens after bile duct damage has occurred but may be more directly related to the disease process.

Serology of primary biliary cirrhosis.

The aetiology of primary biliary cirrhosis (PBC) still remains unknown. Many features point towards an autoimmune disorder [25]: the female preponderance, the familial aggregation, the association with other autoimmune conditions, the protracted course, the presence of various types of antibodies (smooth muscle (SMA), nuclear (ANA), and especially mitochondrial antibodies (AMA)), and the histological lesions (showing granuloma formation and infiltration of bile ducts by lymphocytes). In addition in a high percentage of patients circulating cryoglobulins have been detected [91] and there is a striking abnormality of the complement system [45] and impairment of cell mediated immunity [62]. Also cellular immunity against biliary antigens [64] and mitochondria [18] has been described, and patients’ lymphocytes also seem to interfere in vitro with some mitochondrial functions [16, 24]. AMA apparently play no role in the pathogenesis of PBC but their incidence in almost 90% of all PBC patients led to the speculation that these antibodies could be related to the aetiology of the disease.

Leukocyte migration inhibition in response to biliary antigens in primary biliary cirrhosis, sclerosing cholangitis, and other chronic liver diseases

The leukocyte migration inhibition test has been used to investigate cellular immune responses to antigens in a protein fraction (BPF) of normal human gallbladder bile in patients with a variety of intraand extrahepatic diseases. Inhibition of leukocyte migration in the presence of BPF was observed in 30 (81%) of 37 patients with PBC, in 8 (80%) of 10 patients with sclerosing cholangitis, and in 7 (26%) of 27 patients with chronic active hepatitis. Only 1 of 31 patients with other liver diseases or with uncomplicated ulcerative colitis showed a similar response to BPF. The BPF was found to contain three antigens which were distinct from plasma proteins. Immuno-fluorescence studies revealed that one of these antigens appears to be derived from that part of the hepatocellular membrane which forms the bile canaliculus and that a second appears to be associated with the epithelial cell membranes of interlobular and septal bile ducts. The site of origin of the third antigen could not be established. It is suggested that cellular immune responses to biliary antigens could be involved in the progressive bile duct destruction of chronic biliary disease.

Cellular Immune Responses to Biliary Tract Antigens in Primary Biliary Cirrhosis and Chronic Active Hepatitis

Cellular Immune Responses to Biliary Tract Antigens in Primary Biliary Cirrhosis and Chronic Active Hepatitis