The chemokine receptor CXCR5 is pivotal for ectopic mucosa-associated lymphoid tissue neogenesis in chronic Helicobacter pylori-induced inflammation

Ectopic lymphoid follicles are a key feature of chronic inflammatory autoimmune and infectious diseases, such as rheumatoid arthritis, Sjögren's syndrome, and Helicobacter pylori-induced gastritis. Homeostatic chemokines are considered to be involved in the formation of such tertiary lymphoid tissue. High expression of CXCL13 and its receptor, CXCR5, has been associated with the formation of ectopic lymphoid follicles in chronic infectious diseases. Here, we defined the role of CXCR5 in the development of mucosal tertiary lymphoid tissue and gastric inflammation in a mouse model of chronic H. pylori infection. CXCR5-deficient mice failed to develop organized gastric lymphoid follicles despite similar bacterial colonization density as infected wild-type mice. CXCR5 deficiency altered Th17 responses but not Th1-type cellular immune responses to H. pylori infection. Furthermore, CXCR5-deficient mice exhibited lower H. pylori-specific serum IgG and IgA levels and an overall decrease in chronic gastric immune responses. In conclusion, the development of mucosal tertiary ectopic follicles during chronic H. pylori infection is strongly dependent on the CXCL13/CXCR5 signaling axis, and lack of de novo lymphoid tissue formation attenuates chronic immune responses

The immunobiology of primary sclerosing cholangitis

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease histologically characterized by the presence of intrahepatic and/or extrahepatic biliary duct concentric, obliterative fibrosis, eventually leading to cirrhosis. Approximately 75% of patients with PSC have inflammatory bowel disease. The male predominance of PSC, the lack of a defined, pathogenic autoantigen, and the potential role of the innate immune system suggest that it may be due to dysregulation of immunity rather than a classic autoimmune disease. However, PSC is associated with several classic autoimmune diseases, and the strongest genetic link to PSC identified to date is with the human leukocyte antigen DRB01*03 haplotype. The precise immunopathogenesis of PSC is largely unknown but likely involves activation of the innate immune system by bacterial components delivered to the liver via the portal vein. Induction of adhesion molecules and chemokines leads to the recruitment of intestinal lymphocytes. Bile duct injury results from the sustained inflammation and production of inflammatory cytokines. Biliary strictures may cause further damage as a result of bile stasis and recurrent secondary bacterial cholangitis. Currently, there is no effective therapy for PSC and developing a rational therapeutic strategy demands a better understanding of the disease

Lymphocyte recruitment and homing to the liver in primary biliary cirrhosis and primary sclerosing cholangitis

The mechanisms operating in lymphocyte recruitment and homing to liver are reviewed. A literature review was performed on primary biliary cirrhosis (PBC), progressive sclerosing cholangitis (PSC), and homing mechanisms; a total of 130 papers were selected for discussion. Available data suggest that in addition to a specific role for CCL25 in PSC, the CC chemokines CCL21 and CCL28 and the CXC chemokines CXCL9 and CXCL10 are involved in the recruitment of T lymphocytes into the portal tract in PBC and PSC. Once entering the liver, lymphocytes localize to bile duct and retain by the combinatorial or sequential action of CXCL12, CXCL16, CX3CL1, and CCL28 and possibly CXCL9 and CXCL10. The relative importance of these chemokines in the recruitment or the retention of lymphocytes around the bile ducts remains unclear. The available data remain limited but underscore the importance of recruitment and homing

Impact of exploratory biomarkers on the treatment effect of bevacizumab in metastatic breast cancer.

PURPOSE: The addition of bevacizumab to cytotoxic chemotherapy has demonstrated a progression-free survival (PFS) benefit in the first-line and second-line treatment of advanced or metastatic breast cancer (MBC). However, the addition of bevacizumab to capecitabine in heavily pretreated MBC patients did not show a PFS benefit (AVF2119g phase III trial). The aim of this study was to evaluate the expression of novel putative biomarkers as predictors of benefit from bevacizumab in retrospective subset analyses of the AVF2119g trial. EXPERIMENTAL DESIGN: In the AVF2119g trial, 462 patients with MBC were randomly assigned to receive capecitabine or capecitabine plus bevacizumab. Primary tumor tissue and outcome data were available for 223 patients. Biomarker expression was assessed by in situ hybridization (VEGF-A, VEGF-B, thrombospondin-2 and Flt4) or immunohistochemistry (VEGF-C, PDGF-C, neuropilin-1, delta-like ligand (Dll) 4, Bv8, p53 and thymidine phosphorylase) on formalin-fixed, paraffin-embedded tissue. PFS was associated with these variables in retrospective subset analyses. RESULTS: Patients with low scores for Dll4, VEGF-C, and neuropilin-1 showed trends toward improvement in PFS associated with the addition of bevacizumab to capecitabine (P values = 0.01, 0.05, and 0.07, respectively). These observations were not statistically significant following correction for multiple hypothesis testing. CONCLUSION: These retrospective subset analyses suggest that expression of Dll4, VEGF-C, and neuropilin-1 may predict benefit from bevacizumab. Such observations are not conclusive but warrant additional testing