Hepatic lymphocytes involved in the pathogenesis of pediatric and adult non-alcoholic fatty liver disease.

The immune response is critical in NAFLD pathogenesis, but the liver infiltrate's composition and the role of each T cell population is still up for debate. To characterize liver pathogenesis in pediatric and adult cases, frequency and localization of immune cell populations [Cytotoxic T Lymphocytes (CD8+), T helper Lymphocytes (CD4+), Regulatory T lymphocytes (Foxp3+) and Th17 (IL-17A+)] were evaluated. In portal/periportal (P/P) tracts, both age groups displayed a similar proportion of CD8+ and CD4+ lymphocytes. However, comparable Foxp3+ and IL-17A+ cell frequencies were observed in pediatric cases, meanwhile, in adults Foxp3+ was higher than IL-17A+ cells. Interestingly, IL-17A+ lymphocytes seemed to be nearly exclusive of P/P area in both age groups. In intralobular areas, both pediatric and adult cases showed CD8+ lymphocytes predominance with lower frequencies of CD4+ lymphocytes followed by Foxp3+ . Severe inflammation was associated with higher intralobular Foxp3+ lymphocytes (p = 0.026) in children, and lower P/P Foxp3+ and higher IL-17A+ lymphocytes in adults. All cases with fibrosis ≥ 2 displayed P/P low Foxp3+ and high IL-17A+ lymphocyte counts. Pediatric cases with worse steatosis showed high P/P CD4+ (p = 0.023) and intralobular CD8+ (p = 0.027) and CD4+ cells (p = 0.012). In NAFLD cases, the lymphocyte liver infiltrate composition differs between histological areas. Treg and Th17 balance seems to condition damage progression, denoting their important role in pathogenesis.

Nonalcoholic fatty liver disease: biomarkers as diagnostic tools for liver damage assessment in adult patients from Argentina.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease whose prevalence has been increasing constantly and linked to the global obesity epidemic. The NAFLD histologic spectrum ranges from simple steatosis to nonalcoholic steatohepatitis (NASH), which can progress to cirrhosis and hepatocellular carcinoma. Liver biopsy is the only reliable means to diagnose and stage NASH, but its invasive nature limits its use. Therefore, the prediction of hepatic injury by means of the development of new noninvasive tests represents a growing medical need. Our aim was to evaluate matrix deposition and cell-death markers, which correlate with liver injury in an NAFLD patient cohort. PATIENTS AND METHODS: Liver biopsies and serum from 34 NAFLD adult patients were analyzed. Histological parameters were evaluated. Matrix deposition [hyaluronic acid (HA) and tissue inhibitor of matrix metalloproteinase inhibitor-1 (TIMP-1)] and cell-death markers [cytokeratin-18 (M65) and caspase-cleaved cytokeratin-18 (M30)] were measured in serum samples. RESULTS: HA showed an association with fibrosis severity (P=0.03) and M30 with steatosis (P=0.013), inflammation (P=0.004), and fibrosis severity (P=0.04). In contrast, TIMP-1 and M65 showed no association with any histological parameter of liver injury. The evaluation of diagnostic accuracy showed good performance as less invasive markers of significant fibrosis of both HA (area under the receiver operating characteristic curve: 0.928) and M30 (area under the receiver operating characteristic curve: 0.848). CONCLUSION: Biomarkers are essential tools that may provide a quick and accurate diagnosis for patients with life-threatening NAFLD and NASH. HA and M30, together or determined sequentially, have been found to be straightforward tests that may be sufficient to predict significant fibrosis even in a primary care center of an underdeveloped country.

Nasal immunization with Burkholderia multivorans outer membrane proteins and the mucosal adjuvant adamantylamide dipeptide confers efficient protection against experimental lung infections with B. multivorans and B. cenocepacia.

Chronic lung infection by opportunistic pathogens, such as Pseudomonas aeruginosa and members of the Burkholderia cepacia complex, is a major cause of morbidity and mortality in patients with cystic fibrosis. Outer membrane proteins (OMPs) of gram-negative bacteria are promising vaccine antigen candidates. In this study, we evaluated the immunogenicity, protection, and cross-protection conferred by intranasal vaccination of mice with OMPs from B. multivorans plus the mucosal adjuvant adamantylamide dipeptide (AdDP). Robust mucosal and systemic immune responses were stimulated by vaccination of naive animals with OMPs from B. multivorans and B. cenocepacia plus AdDP. Using a mouse model of chronic pulmonary infection, we observed enhanced clearance of B. multivorans from the lungs of vaccinated animals, which correlated with OMP-specific secretory immunoglobulin A responses. Furthermore, OMP-immunized mice showed rapid resolution of the pulmonary infection with virtually no lung pathology after bacterial challenge with B. multivorans. In addition, we demonstrated that administration of B. multivorans OMP vaccine conferred protection against B. cenocepacia challenge in this mouse infection model, suggesting that OMPs provide cross-protection against the B. cepacia complex. Therefore, we concluded that mucosal immunity to B. multivorans elicited by intranasal vaccination with OMPs plus AdDP could prevent early steps of colonization and infection with B. multivorans and also ameliorate lung tissue damage, while eliciting cross-protection against B. cenocepacia. These results support the notion that therapies leading to increased mucosal immunity in the airways may help patients with cystic fibrosis.

Intranasal vaccination with recombinant outer membrane protein CD and adamantylamide dipeptide as the mucosal adjuvant enhances pulmonary clearance of Moraxella catarrhalis in an experimental murine model.

Moraxella catarrhalis causes acute otitis media in children and lower respiratory tract infections in adults and elderly. In children the presence of antibodies against the highly conserved outer membrane protein CD correlates with protection against infection, suggesting that this protein may be useful as a vaccine antigen. However, native CD is difficult to purify, and it is still unclear if recombinant CD (rCD) is a valid alternative. We performed a side-by-side comparison of the immunogenicities and efficacies of vaccine formulations containing native CD and rCD with adamantylamide dipeptide as the mucosal adjuvant. Intranasal vaccination of mice stimulated the production of high CD-specific antibody titers in sera and of secretory immunoglobulin A in mucosal lavages, which cross-recognized both antigens. While vaccination with native CD increased the number of interleukin-2 (IL-2)- and gamma interferon-producing cells, rCD mainly stimulated IL-4-secreting cells. Nevertheless, efficient bacterial clearance was observed in the lungs of challenged mice receiving native CD and in the lungs of challenged mice receiving rCD (96% and 99%, respectively). Thus, rCD is a promising candidate for incorporation in vaccine formulations for use against M. catarrhalis.

Intranasal vaccination with recombinant P6 protein and adamantylamide dipeptide as mucosal adjuvant confers efficient protection against otitis media and lung infection by nontypeable Haemophilus influenzae.

Nontypeable Haemophilus influenzae (NTHi) is a leading etiologic agent of otitis media in children and recurrent respiratory infections in patients with chronic obstructive pulmonary disease. The highly conserved outer membrane protein P6 constitutes a promising vaccine candidate antigen. However, the small amount of P6 produced by this fastidious microorganism renders large-scale production difficult. Controversial data also exist concerning the suitability of recombinant P6 (rP6) as a vaccine antigen. Therefore, we performed a comparative evaluation of the immunogenicity and efficacy of native P6 and rP6 in mice intranasally vaccinated with adamantylamide dipeptide (AdDP) as an adjuvant. High titers of P6-specific serum antibodies were elicited in mice vaccinated with either native P6 or rP6, which cross-recognized both antigens. However, rP6 stimulated stronger mucosal responses. Mice vaccinated with rP6 were protected against both pulmonary and middle-ear infections (P<.01). This demonstrates that rP6 plus AdDP constitutes a promising vaccine formulation against the most relevant forms of disease caused by NTHi.