Liver Is Able to Activate Naïve CD8+ T Cells with Dysfunctional Anti-Viral Activity in the Murine System

The liver possesses distinct tolerogenic properties because of continuous exposure to bacterial constituents and nonpathogenic food antigen. The central immune mediators required for the generation of effective immune responses in the liver environment have not been fully elucidated. In this report, we demonstrate that the liver can indeed support effector CD8+ T cells during adenovirus infection when the T cells are primed in secondary lymphoid tissues. In contrast, when viral antigen is delivered predominantly to the liver via intravenous (IV) adenovirus infection, intrahepatic CD8+ T cells are significantly impaired in their ability to produce inflammatory cytokines and lyse target cells. Additionally, intrahepatic CD8+ T cells generated during IV adenovirus infection express elevated levels of PD-1. Notably, lower doses of adenovirus infection do not rescue the impaired effector function of intrahepatic CD8+ T cell responses. Instead, intrahepatic antigen recognition limits the generation of potent anti-viral responses at both priming and effector stages of the CD8+ T cell response and accounts for the dysfunctional CD8+ T cell response observed during IV adenovirus infection. These results also implicate that manipulation of antigen delivery will facilitate the design of improved vaccination strategies to persistent viral infection

Snail1 factor behaves as a therapeutic target in renal fibrosis.

Kidney fibrosis is a devastating disease that leads to organ failure, and no specific treatment is available to preserve organ function. In fibrosis, myofibroblasts accumulate in the interstitium leading to massive deposition of extracellular matrix and organ disfunction. The origin of myofibroblasts is multiple and the contribution of renal epithelial cells after undergoing epithelial-to-mesenchymal transition (EMT) is still debated. In a model unable to reactivate the EMT inducer Snail1 upon damage, we show that Snail1 is required in renal epithelial cells for the development of fibrosis. Damage-mediated Snail1 reactivation induces a partial EMT that relays fibrotic and inflammatory signals to the interstitium through the activation of TGF-β and NF-B pathways. Snail1-induced fibrosis can be reverted in vivo and inhibiting Snail1 in a model of obstructive nephropathy highly ameliorates fibrosis. These results reconcile conflicting data on the role of EMT in renal fibrosis and provide avenues for the design of antifibrotic therapies.pre-print8435 K

Immunization with Radiation-Attenuated Plasmodium berghei Sporozoites Induces Liver cCD8α+DC that Activate CD8+T Cells against Liver-Stage Malaria

Immunization with radiation (γ)-attenuated Plasmodia sporozoites (γ-spz) confers sterile and long-lasting immunity against malaria liver-stage infection. In the P. berghei γ-spz model, protection is linked to liver CD8+ T cells that express an effector/memory (TEM) phenotype, (CD44hiCD45RBloCD62Llo ), and produce IFN-γ. However, neither the antigen presenting cells (APC) that activate these CD8+ TEM cells nor the site of their induction have been fully investigated. Because conventional (c)CD8α+ DC (a subset of CD11c+ DC) are considered the major inducers of CD8+ T cells, in this study we focused primarily on cCD8α+ DC from livers of mice immunized with Pb γ-spz and asked whether the cCD8α+ DC might be involved in the activation of CD8+ TEM cells. We demonstrate that multiple exposures of mice to Pb γ-spz lead to a progressive and nearly concurrent accumulation in the liver but not the spleen of both the CD11c+NK1.1− DC and CD8+ TEM cells. Upon adoptive transfer, liver CD11c+NK1.1− DC from Pb γ-spz-immunized mice induced protective immunity against sporozoite challenge. Moreover, in an in vitro system, liver cCD8α+ DC induced naïve CD8+ T cells to express the CD8+ TEM phenotype and to secrete IFN-γ. The in vitro induction of functional CD8+ TEM cells by cCD8α+ DC was inhibited by anti-MHC class I and anti-IL-12 mAbs. These data suggest that liver cCD8α+ DC present liver-stage antigens to activate CD8+ TEM cells, the pre-eminent effectors against pre-erythrocytic malaria. These results provide important implications towards a design of anti-malaria vaccines

Maternal Undernutrition and Long-term Effects on Hepatic Function

Undernutrition in utero, regardless of the source, can impair proper liver development leading to long-term metabolic dysfunction. Understanding the molecular mechanisms underlying how nutritional deficits during perinatal life lead to permanent alterations in hepatic gene expression will provide better therapeutic strategies to alleviate the undernourished liver in postnatal life. This chapter addresses the different experimental models of undernutrition in utero, and highlights the direct and indirect mechanisms involved leading to metabolic diseases in the liver. These include hypoxia, oxidative stress, epigenetic alterations, and endoplasmic reticulum (ER) stress. In addition, promising perinatal nutritional and pharmaceutical interventions are highlighted which illustrate how the placidity of the developing liver can be exploited to prevent the onset of long-term metabolic disease

Antibiotic prophylaxis for ERCP: a randomized clinical trial comparing ciprofloxacin and cefuroxime in 200 patients at high risk of cholangitis.

OBJECTIVE: To compare the efficacy and safety of oral ciprofloxacin and intravenous cefuroxime in patients at high risk of cholangitis after endoscopic retrograde cholangiopancreatography (ERCP). DESIGN: Prospective, randomized study. SETTING: A primary and tertiary referral centre. PATIENTS: A series of 232 consecutive patients who either had radiological evidence of biliary obstruction or were aged over 70 years were randomly assigned to receive either oral ciprofloxacin or intravenous cefuroxime before and after ERCP. Two-hundred and nine patients finished the study, with 23 being excluded because of withdrawal of consent or incomplete ERCP. INTERVENTIONS: Patients underwent ERCP: blood samples were taken for culture, full blood count and biochemistry before and after the procedure. Clinical follow-up was carried out 7 and 42 days after ERCP. MAIN OUTCOME MEASURES: Clinical, bacteriological or biochemical evidence of cholangitis, septicaemia or adverse drug reactions, and the cost of both protocols. RESULTS: Follow-up was recorded in all 209 patients who completed the study. By 42 days after ERCP, three patients had died (cholangiocancer, pancreatic cancer and renal failure). Cholangitis was diagnosed in one patient from each of the two trial groups. Blood cultures from the patient on ciprofloxacin gave negative results, but a post-ERCP blood sample from the patient on cefuroxime grew Pseudomonas aeruginosa, which was sensitive to ciprofloxacin. There were no serious side-effects in either study group, but two patients assigned to ciprofloxacin became too nauseous to take the medication. The cost of the cefuroxime protocol was l7.56 pounds per patient, compared with 4.76 pounds per patient for the ciprofloxacin protocol. CONCLUSION: A pre- and post-ERCP oral ciprofloxacin regime is safe and provides effective prophylaxis against ERCP-induced cholangitis and septicaemia in high-risk patients. It is also more economical than a regime of intravenous cefuroxime and does not require nursing staff with training in intravenous techniques

A survey of cytomegalovirus (CMV) DNA in primary sclerosing cholangitis (PSC) liver tissues using a sensitive polymerase chain reaction (PCR) based assay.

Reactivation of cytomegalovirus (CMV) has been implicated as a possible etiological agent in primary sclerosing cholangitis (PSC) partly because of the ability of CMV infection to cause hepatobiliary damage, and further because of the recent recognition of a PSC-like syndrome in AIDS patients, many of whom have hepatobiliary infection with CMV. Direct evidence of CMV infection in PSC has come from a study detecting CMV DNA in 7/7 PSC livers, but only 5/20 controls. We have developed an assay for CMV-DNA by amplification of the immediate early region of CMV using the polymerase chain reaction, followed by Southern blotting and 32P oligoprobing of the amplification product. This system has an average sensitivity of at least 25 copies of CMV-DNA per 5000 formalin-fixed paraffin-embedded cells. 37 PSC and 19 control samples of formalin-fixed paraffin-embedded hepatobiliary tissues were studied. Amplification for the beta-globin in each sample was used as an amplification control, and fetal lung with known CMV infection as the CMV-positive control. 37/37 PSC tissues amplified for beta-globin, and one of these was positive for CMV-DNA. All 19 controls amplified for beta-globin, with none being positive for CMV. The lack of CMV-DNA in 35/36 PSC samples at a level of 25 copies per 5000 cells, we believe, rules out any significant CMV reactivation in these tissues, and suggests that CMV replication and re-activation is not responsible for the progression of PSC

HLA DR4 is a marker for rapid disease progression in primary sclerosing cholangitis.

BACKGROUND/AIMS: Primary sclerosing cholangitis (PSC) is an inflammatory disease of the biliary tree associated with an increase in the HLA alleles DR3, DR52a, DR2, Dw2, and a decrease in DR4. However, it is not certain which of these alleles provides the primary associations. Our aim was to establish the primary HLA associations with PSC and to assess the ability of HLA alleles to mark for disease progression. METHODS: By applying molecular techniques to archival tissue, we have genotyped 83 PSC patients from two populations and 131 controls for the alleles HLA DR2, DR3, DR4, DRw12, DR52a, and Dw2. RESULTS: HLA DR3, DR52a, DR2, and Dw2 were all significantly increased in PSC, with the relative risk for DR52a and Dw2 being greater than for DR3 and DR2, respectively. HLA DR4 was significantly decreased, but this may be artifactual to the DR3, DR2 increase. HLA DR4 and not DR52a marks for rapid disease progression in both our PSC populations. CONCLUSIONS: HLA DR52a and Dw2 are the best candidate alleles for providing the known HLA association with PSC. HLA DR4 and not DR52a marks for rapid disease progression in our two PSC populations