Silencing of tumoral carbohydrate sulfotransferase 15 reactivates lymph node pancreatic cancer T cells in mice.

Limited intratumoral T-cell infiltration in pancreatic ductal adenocarcinoma (PDAC) is an obstacle to immunotherapy, yet the efficient approach to enhance tumor-infiltrating T cells is not fully established. Here, we show that tumor-specific knockdown of carbohydrate sulfotransferase 15 (CHST15), a tumor stromal proteoglycan-synthetic enzyme, suppresses tumor growth in a T-cell-dependent manner in a murine model of PDAC. Silencing of tumoral CHST15 unexpectedly expanded CD4+ and CD8+ T cells in tumor draining LN (TDLN), leading to accelerated accumulation of EdU+ proliferating CD4+ and CD8+ T cells and granzyme B+ CD8+ T cells in the tumor. RNA expression analysis indicated that tumoral CHST15 knockdown (KD) downregulated matrix remodeling-related genes, while upregulated anti-tumor T-cell activity-related genes in both tumor and TDLN. CHST15 KD significantly diminished intratumoral and TDLN Ly6C/G+ myeloid-derived suppressor cells prior to TDLN T-cell expansion, suggesting that tumoral CHST15 remotely regulated myeloid-derived suppressor cell mediated T-cell suppression in the TDLN. Our findings illustrate a novel immunotherapeutic potential of tumoral CHST15 blockage by reactivating T cells in immune suppressive TDLN of PDAC.

Terrestrial anaerobic digestate composite for fertilization of oligotrophic coastal seas.

To promote primary production in oligotrophic seas, we developed a fertilization composite consisting of blast furnace cement and anaerobic digestate with a high nutrient content derived from biogas power plant byproducts. In this study, we investigated the dissolution behavior of nutrients from the fertilization composite and evaluated the effects of the fertilization composite on the growth of marine primary producers. Batch experiments and tank experiments to simulate oligotrophic coastal seas revealed that the nutrients dissolved from the fertilization composite were taken up by marine microalgae and seaweed. The fertilization composite promoted the growth of both planktonic and benthic micro algae. The total amounts of chlorophyll a in the fertilization composite tank increased by 1.4 times compared to control (p < 0.01). The flow of dissolved inorganic nitrogen uptake by marine microalgae increased 3-5 times when the fertilization composite was applied. In Wakame seaweed culture experiments, the nitrogen contents of Wakame from the fertilization composite tank were 1.2 times higher than those cultured in the control tank (p < 0.01). As a result, Wakame leaves cultured in the fertilization composite tank were 1.4 times longer than those cultured in the control tank. Approximately 44% of dissolved inorganic nitrogen from the fertilization composite was taken up by the seaweed. Hence, the fertilization composite was demonstrated to enhance the growth of marine microalgae and seaweed, which are primary producers in marine ecosystems. The fertilization composite proposed in this study can create novel nutrient mass flow by connecting terrigenous anaerobic digestate from biogas power plants to oligotrophic seas and thus stimulate the recovery of fishery production.

Prevention of esophageal stricture after endoscopic submucosal dissection using RNA-based silencing of carbohydrate sulfotransferase 15 in a porcine model.

Background and study aims Endoscopic submucosal dissection (ESD) for esophageal carcinoma frequently causes fibrotic strictures that require treatment. A possible preventive effect of small interfering RNA (siRNA) targeting carbohydrate sulfotransferase 15 (CHST15) on esophageal stricture formation after ESD was investigated in 3 pigs. Materials and methods Two half-circumferential ESD ulcers were created in the oral and anal ends of the esophagus. CHST15 siRNA was injected submucosally in one of the two ESD ulcers. Endoscopic, macroscopic, histological, and polymerase chain reaction analyses were performed. Results On post-operative day 14, the non-treated ulcers were found to show histological fibrosis and increased expression of the CHST15 messenger RNA. A single endoscopic injection of CHST15 siRNA alleviated stricture development in post-ESD ulcers with significant reduction in the mucosal contraction rate. The deposition of collagen and accumulation of fibroblasts and myofibroblasts were diminished in ulcers treated with CHST15 siRNA, where significant suppression of CHST15, transforming growth factor-beta (TGF-ß), and collagen-1 messenger RNAs was also seen. Conclusion CHST15 siRNA alleviated esophageal post-ESD stricture formation via repression of fibrosis, revealing a novel therapeutic role for antifibrotic agents in the prevention of post-ESD strictures.

RNA interference targeting carbohydrate sulfotransferase 3 diminishes macrophage accumulation, inhibits MMP-9 expression and promotes lung recovery in murine pulmonary emphysema.

BACKGROUND: Chondroitin sulfate proteoglycans are an important mediators in inflammation and leukocyte trafficking. However, their roles in pulmonary emphysema have not been explored. In a murine model of elastase-induced pulmonary emphysema, we found increased carbohydrate sulfotransferase 3 (CHST3), a specific enzyme that synthesizes chondroitin 6-sulfate proteoglycan (C6SPG). To elucidate the role of C6SPG, we investigated the effect of small interfering RNA (siRNA) targeting CHST3 that inhibits C6SPG-synthesis on the pathogenesis of pulmonary emphysema. METHODS: Mice were intraperitoneally injected with CHST3 siRNA or negative control siRNA on day0 and 7 after intratracheal instillation of elastase. Histology, respiratory function, glycosaminoglycans (GAGs) content, bronchoalveolar lavage (BAL), elastin staining and gene expressions of tumor necrosis factor (TNF)-α and matrix metalloproteinase (MMP)-9 mRNA were evaluated on day7 and/or day21. RESULTS: CHST3 mRNA increased at day 7 and decreased thereafter in lung. CHST3 siRNA successfully inhibited the expression of CHST3 mRNA throughout the study and this was associated with significant reduction of GAGs and C6SPG. Airway destruction and respiratory function were improved by the treatment with CHST3 siRNA. CHST3 siRNA reduced the number of macrophages both in BAL and lung parenchyma and also suppressed the increased expressions of TNF-α and MMP-9 mRNA. Futhermore, CHST3 siRNA improved the reduction of the elastin in the alveolar walls. CONCLUSIONS: CHST3 siRNA diminishes accumulation of excessive macrophages and the mediators, leading to accelerate the functional recovery from airway damage by repair of the elastin network associated with pulmonary emphysema.

Linagliptin alleviates hepatic steatosis and inflammation in a mouse model of non-alcoholic steatohepatitis.

Non-alcoholic steatohepatitis (NASH) is a primary cause of cirrhosis and hepatocellular carcinoma. Dipeptidyl peptidase (DPP)-4 inhibitors are established therapies for type 2 diabetes and although DPP-4 inhibitors can reduce hepatic steatosis, their impact on local inflammation and fibrosis in NASH remains unknown. Using two different experimental treatment regimens (4- and 2-week treatments) in streptozotocin-treated neonatal mice on a high-fat diet, we show that the DPP-4 inhibitor linagliptin (10 and 30 mg/kg) significantly attenuated the NAS score from 4.9 ± 0.6 to 3.7 ± 0.4 and 3.6 ± 0.3, respectively, in the 4-week study. In the 2-week study, linagliptin 10 mg/kg significantly reduced NAS score from 4.1 ± 0.4 to 2.4 ± 0.4. Telmisartan was used as a positive control in both studies and lowered NAS score to 1.9 ± 0.7 and 1.4 ± 0.3, respectively. Due to streptozotocin treatment, elevated glucose levels were unchanged by either drug treatment. Further, linagliptin 10 mg/kg significantly reduced mRNA levels of SOCS-3 (from 1.68 ± 0.2 to 0.83 ± 0.08), IFN-γ (from 4.0 ± 0.5 to 2.3 ± 0.3), and TNF-α (from 5.7 ± 0.5 to 2.13 ± 0.3). The latter observation was confirmed by immunohistochemistry of TNF-α in liver specimens. In addition, using microautoradiography, we showed that the distribution of radiolabeled linagliptin was heterogeneous with the highest density associated with interlobular bile ducts and portal tracts (acini). In conclusion, these studies confirm that linagliptin has high exposure in hepatic tissue and has both anti-inflammatory and anti-steatotic activity in NASH.

Add-on multiple submucosal injections of the RNA oligonucleotide GUT-1 to anti-TNF antibody treatment in patients with moderate-to-severe ulcerative colitis: an open-label, proof-of concept study.

BACKGROUND: Carbohydrate sulfotransferase 15 (CHST15) is an enzyme biosynthesizing matrix glycosaminoglycan that modulates tissue remodeling. We evaluated the efficacy of add-on submucosal injections of GUT-1, the RNA oligonucleotide inhibitor of CHST15, to ongoing anti-tumor necrosis factor (TNF) antibody treatment in patients with moderate-to-severe ulcerative colitis (UC). METHODS: This was an open-label study of 250 nM of GUT-1 by endoscopic submucosal injections at weeks 0, 2, 4 in five UC patients who lost response during maintenance treatment to anti-TNF antibodies. The primary endpoint was the rate of endoscopic improvement at week 6 and secondary endpoints included the rates of clinical remission by modified Mayo Score (mMS). Patients received follow-up observation with continuous maintenance treatment by the same anti-TNF antibody till the time of clinical recurrence or for overall 52 weeks. RESULTS: At week 6, rates of endoscopic improvement and clinical remission were 80% (n = 4/5) and 60% (n = 3/5), respectively. The mean Endoscopy Subscore was reduced from 2.4 (95%CI: 1.7 to 3.1) at baseline, to 1.0 (95%CI: 0.1 to 1.9) at week 6. The mean mMS was reduced from 7.8 (95%CI: 6.2 to 9.4) to 1.3 (95%CI: 2.9 to 4.3). GUT-1 was well tolerated. Three patients did not show clinical recurrence for 52 weeks. All three corticosteroid-dependent patients showed no corticosteroid exposure for at least 24 weeks after achieving clinical remission. Multiple dosing was also well tolerated. CONCLUSIONS: Add-on multiple injections of GUT-1 to ongoing anti-TNF antibody was able to induce rapid and durable clinical responses in UC patients who lost response to anti-TNF therapy. TRIAL REGISTRATION: Clinical trial Registration Number (Japan): UMIN000020900.

Intra-tumoral administration of CHST15 siRNA remodels tumor microenvironment and augments tumor-infiltrating T cells in pancreatic cancer.

The dense stroma is one cause of poor efficacy of T cell-mediated immunotherapy in pancreatic ductal adenocarcinoma (PDAC). Carbohydrate sulfotransferase 15 (CHST15) is a proteoglycan-synthetic enzyme responsible for remodeling tumor stroma. Intra-tumoral injection of CHST15 small interfering RNA (siRNA) has been shown to increase the tumor-infiltrating T cells (TILs) in patients with unresectable PDAC. However, the mechanism underlying the enhanced accumulation of TILs is not fully explored. Here, we demonstrate that intra-tumoral injection of CHST15 siRNA locally and remotely diminishes myeloid-derived suppressor cells (MDSCs) and enhances TILs in mice. CHST15 was expressed by tumor cells and MDSCs in both tumor and tumor-draining lymph nodes (TDLNs), and CHST15 siRNA repressed stromal density, neutrophil extracellular traps, and Ly6C/G+ MDSCs in vivo. Remarkably, tumor growth inhibition was only observed in the immunocompetent KPC model, which is associated with enhanced TILs. In vitro, CHST15 siRNA significantly downregulated the levels of CHST15 and indoleamine 2,3-dioxygenase mRNA in CD33+ MDSCs derived from human peripheral blood mononuclear cells. These results suggest a dual role for intra-tumorally injected CHST15 siRNA on modulating the tumor immune microenvironment for T cell entry and remotely diminishing CHST15+ MDSCs, decreasing T cell suppression and expanding T cells in the TDLN, ultimately leading to an enhanced accumulation of TILs.

Submucosal Injection of the RNA Oligonucleotide GUT-1 in Active Ulcerative Colitis Patients: A Randomized, Double-Blind, Placebo-Controlled Phase 2a Induction Trial.

BACKGROUND AND AIMS: Carbohydrate sulfotransferase 15 [CHST15] biosynthesizes sulphated matrix glycosaminoglycans and is implicated in intestinal inflammation and fibrosis. Here, we evaluate the efficacy and safety of the double-stranded RNA oligonucleotide GUT-1, a specific blocker of CHST15, as induction therapy in patients with ulcerative colitis [UC]. METHODS: In this randomized, double-blind, placebo-controlled, phase 2a study, we enrolled endoscopically active UC patients, refractory to conventional therapy, in five hospital centres across Germany. Patients were randomized 1:1:1 using a block randomized technique to receive a single dosing of 25 nM GUT-1, 250 nM GUT-1, or placebo by endoscopic submucosal injections. The primary outcome measure was improvement of endoscopic lesions at weeks 2 or 4. The secondary outcome measures included clinical and histological responses. Safety was assessed in all patients who received treatment. RESULTS: Twenty-eight patients were screened, 24 were randomized, and 21 were evaluated. Endoscopic improvement at weeks 2 or 4 was achieved by 71.4% in the GUT-1 250 nM, 0% in the GUT-1 25 nM, and 28.6% in the placebo group. Clinical remission was shown by 57.1% in the GUT-1 250 nM, 0% in the GUT-1 25 nM, and 14.3% in the placebo groups. Histological improvement was shown by 42.9% in the GUT-1 250 nM, 0% in the GUT-1 25 nM, and 0% in the placebo groups. GUT-1 250 nM reduced CHST15 expression significantly and suppressed mucosal inflammation and fibrosis. GUT-1 application was well tolerated. CONCLUSION: Single dosing by submucosal injection of GUT-1 repressed CHST15 mucosal expression and may represent a novel induction therapy by modulating tissue remodelling in UC.

Inhibition of Glutaminyl Cyclases alleviates CCL2-mediated inflammation of non-alcoholic fatty liver disease in mice.

Inflammation is an integral part of non-alcoholic fatty liver disease (NAFLD), the most prevalent form of hepatic pathology found in the general population. In this context, recently we have examined the potential role of Glutaminyl Cyclases (QC and isoQC), and their inhibitors, in the maturation of chemokines, for example, monocyte chemoattractant protein 1 (MCP-1, CCL2), to generate their bioactive conformation. Catalysis by isoQC leads to the formation of an N-terminal pyroglutamate residue protecting CCL2 against degradation by aminopeptidases. This is of importance because truncated forms possess a reduced potential to attract immune cells. Since liver inflammation is characterized by the up-regulation of different chemokine pathways, and within this CCL2 is known to be a prominent example, we hypothesised that application of QC/isoQC inhibitors may alleviate liver inflammation by destabilizing CCL2. Therefore, we investigated the role of QC/isoQC inhibition, in comparison with the angiotensin receptor blocker Telmisartan, during development of pathology in a mouse model of non-alcoholic fatty liver disease. Application of a QC/isoQC inhibitor led to a significant reduction in circulating alanine aminotransferase and NAFLD activity score accompanied by an inhibitory effect on hepatocyte ballooning. Further analysis revealed a specific reduction of inflammation by decreasing the number of F4/80-positive macrophages, which is in agreement with the proposed CCL2-related mechanism of action of QC/isoQC inhibitors. Finally, QC/isoQC inhibitor application attenuated liver fibrosis as characterized by reduced collagen deposition in the liver parenchyma. Thus in conclusion, QC/isoQC inhibitors are a promising novel class of anti-non-alcoholic steatohepatitis drugs which have a comparable disease-modifying effect to that of Telmisartan, which is probably mediated via specific interference with a comparable monocyte/macrophage infiltration that occurs under inflammatory conditions.

B cells regulate antibody responses through the medullary remodeling of inflamed lymph nodes.

Lymph node (LN) structure is remodeled during immune responses, a process which is considered to play an important role in the regulation of immune function. To date, little attention has been paid to the remodeling of the medullary region, despite its proposed role as a niche for antibody-producing plasma cells. Here, we show that B cells mediate medullary remodeling of antigen-draining LNs during inflammation. This process occurs with kinetics similar to changes in plasma cell number and is accompanied by stromal renetworking which manifests as the segregation of B cells and plasma cells. Medullary remodeling depends on signaling via the lymphotoxin-ß receptor and the presence of B cells but occurs independently of T-dependent humoral responses or other immune cell subsets including T cells, monocytes and neutrophils. Moreover, reconstitution of non-cognate polyclonal B cells in B cell-deficient mice restores not only the medullary remodeling but also the antibody response by separately transferred cognate B cells, suggesting that non-cognate B cells contribute to antibody responses through medullary remodeling. We propose that non-cognate B cells mediate the expansion of the plasma cell niche in LN through medullary remodeling, thereby regulating the size of the LN plasma cell pool.

A murine model for non-alcoholic steatohepatitis showing evidence of association between diabetes and hepatocellular carcinoma.

Hepatocellular carcinoma (HCC) is the third most common cause of cancer-related deaths. In addition to hepatitis viral infections, several cohort studies have shown that diabetes mellitus is a risk factor of HCC, making the incidence alarming high. However, it has not been demonstrated directly how diabetes develops to HCC, because of its difficulty to follow changes of liver histology in diabetic populations. Here, we report that non-alcoholic steatohepatitis (NASH) is pivotal to link diabetes with HCC by establishing a novel, reproducible NASH-HCC model in mice. Neonatal male mice exposed to low-dose streptozotocin (STZ) developed liver steatosis with diabetes 1 week after feeding high-fat diet (HFD). Continuous HFD decreased hepatic fat deposit whilst increased lobular inflammation with foam cell-like macrophages, showing NASH pathology. In parallel with decreased phagocytosis of macrophages, fibroblasts accumulated to form "chicken-wired" fibrosis. All mice developed multiple HCC later. Female mice treated with STZ-HFD and male mice treated with STZ alone showed diabetes but never developed HCC by the absence of NASH-based fibrosis. Thus, the present study provides the evidence in novel mouse model that NASH-based fibrosis is an essential histological process for diabetic populations to accelerate the development of HCC.

A detailed investigation of accessibilities around target sites of siRNAs and miRNAs.

MOTIVATION: The importance of RNA sequence analysis has been increasing since the discovery of various types of non-coding RNAs transcribed in animal cells. Conventional RNA sequence analyses have mainly focused on structured regions, which are stabilized by the stacking energies acting on adjacent base pairs. On the other hand, recent findings regarding the mechanisms of small interfering RNAs (siRNAs) and transcription regulation by microRNAs (miRNAs) indicate the importance of analyzing accessible regions where no base pairs exist. So far, relatively few studies have investigated the nature of such regions. RESULTS: We have conducted a detailed investigation of accessibilities around the target sites of siRNAs and miRNAs. We have exhaustively calculated the correlations between the accessibilities around the target sites and the repression levels of the corresponding mRNAs. We have computed the accessibilities with an originally developed software package, called 'Raccess', which computes the accessibility of all the segments of a fixed length for a given RNA sequence when the maximal distance between base pairs is limited to a fixed size W. We show that the computed accessibilities are relatively insensitive to the choice of the maximal span W. We have found that the efficacy of siRNAs depends strongly on the accessibility of the very 3'-end of their binding sites, which might reflect a target site recognition mechanism in the RNA-induced silencing complex. We also show that the efficacy of miRNAs has a similar dependence on the accessibilities, but some miRNAs also show positive correlations between the efficacy and the accessibilities in broad regions downstream of their putative binding sites, which might imply that the downstream regions of the target sites are bound by other proteins that allow the miRNAs to implement their functions. We have also investigated the off-target effects of an siRNA as a potential RNAi therapeutic. We show that the off-target effects of the siRNA have similar correlations to the miRNA repression, indicating that they are caused by the same mechanism. AVAILABILITY: The C++ source code of the Raccess software is available at http://www.ncrna.org/software/Raccess/ The microarray data on the measurements of the siRNA off-target effects are also available at the same site. CONTACT: kiryu-h@k.u-tokyo.ac.jp

Irsogladine maleate ameliorates inflammation and fibrosis in mice with chronic colitis induced by dextran sulfate sodium.

Intestinal fibrosis is a common and severe complication of inflammatory bowel disease (IBD), especially Crohn's disease (CD). To investigate the therapeutic approach to intestinal fibrosis, we have developed a mouse model of intestinal fibrosis by administering dextran sulfate sodium (DSS) and examining the effects of irsogladine maleate (IM) [2,4-diamino-6-(2,5-dichlorophenyl)-s-triazine maleate], which has been widely used as an antiulcer drug for gastric mucosa in Japan, on DDS-induced chronic colitis. In this experimental colitis lesion, several pathognomonic changes were found: increased deposition of collagen, increased number of profibrogenic mesenchymal cells such as fibroblasts (vimentin(+), α-SMA(-)) and myofibroblasts (vimentin(+), α-SMA(+)) in both mucosa and submucosa of the colon with infiltrating inflammatory cells, and increased mRNA expressions of collagen type I, transforming growth factor (TGF)-ß, matrix metalloproteinase (MMP)-2, and tissue inhibitor of matrix metalloproteinase (TIMP)-1. When IM was administered intrarectally to this colitis, all these pathological changes were significantly decreased or suppressed, suggesting a potential adjunctive therapy for intestinal fibrosis. IM could consequently reduce fibrosis in DSS colitis by direct or indirect effect on profibrogenic factors or fibroblasts. Therefore, the precise effect of IM on intestinal fibrosis should be investigated further.

Plasmacytoid DCs help lymph node DCs to induce anti-HSV CTLs.

Antiviral cell-mediated immunity is initiated by the dendritic cell (DC) network in lymph nodes (LNs). Plasmacytoid DCs (pDCs) are known to migrate to inflamed LNs and produce interferon (IFN)-alpha, but their other roles in antiviral T cell immunity are unclear. We report that LN-recruited pDCs are activated to create local immune fields that generate antiviral cytotoxic T lymphocytes (CTLs) in association with LNDCs, in a model of cutaneous herpes simplex virus (HSV) infection. Although pDCs alone failed to induce CTLs, in vivo depletion of pDCs impaired CTL-mediated virus eradication. LNDCs from pDC-depleted mice showed impaired cluster formation with T cells and antigen presentation to prime CTLs. Transferring circulating pDC precursors from wild-type, but not CXCR3-deficient, mice to pDC-depleted mice restored CTL induction by impaired LNDCs. In vitro co-culture experiments revealed that pDCs provided help signals that recovered impaired LNDCs in a CD2- and CD40L-dependent manner. pDC-derived IFN-alpha further stimulated the recovered LNDCs to induce CTLs. Therefore, the help provided by pDCs for LNDCs in primary immune responses seems to be pivotal to optimally inducing anti-HSV CTLs.

Analysis of intestinal fibrosis in chronic colitis in mice induced by dextran sulfate sodium.

Fibrogenic mesenchymal cells including fibroblasts and myofibroblasts play a key role in intestinal fibrosis, however, their precise role is largely unknown. To investigate their role in intestinal fibrosis, we analyzed the lesions of chronic colitis in C57BL/6 (B6) mice induced by dextran sulfate sodium (DSS). B6 mice exposed to single cycle administration of DSS for 5 days developed acute colitis that progressed to severe chronic inflammation with dense infiltrates of mononuclear cells, irregular epithelial structure, thickening of colonic wall, and persistent deposits of collagen. Increased mRNA expressions of proinflammatory cytokines are correlated with extensive cellular infiltration, and the mRNA expressions of collagen 1, transforming growth factor (TGF)-ß, and matrix metalloproteinases were also enhanced in the colon. In the colon of chronic DSS colitis, fibroblasts (vimentin(+), α-smooth muscle actin (α-SMA)(-)) were increased in both mucosal and submucosal layers, while myofibroblasts (vimentin(+), α-SMA(+)) were increased in mucosal but not in submucosal layers. Primary mouse subcutaneous fibroblast cultures experiments revealed that exogenously added TGF-ß 1 substantially augmented the expressions of both vimentin and α-SMA proteins with increased production of collagen. In conclusion, profibrogenic mesenchymal cells play an important role in the development of intestinal fibrosis in this chronic DSS-induced colitis model.

Chondroitin sulfate in tissue remodeling: Therapeutic implications for pulmonary fibrosis.

Fibrosis is characterized by the deposition of extracellular matrix (ECM) proteins, while idiopathic pulmonary fibrosis (IPF) is a chronic respiratory disease characterized by dysregulated tissue repair and remodeling. Anti-inflammatory drugs, such as corticosteroids and immunosuppressants, and antifibrotic drugs, like pirfenidone and nintedanib, are used in IPF therapy. However, their limited effects suggest that single mediators are inadequate to control IPF. Therefore, therapies targeting the multifactorial cascades that regulate tissue remodeling in fibrosis could provide alternate solutions. ECM molecules have been shown to modulate various biological functions beyond tissue structure support and thus, could be developed into novel therapeutic targets for modulating tissue remodeling. Among ECM molecules, glycosaminoglycans (GAG) are linear polysaccharides consisting of repeated disaccharides, which regulate cell-matrix interactions. Chondroitin sulfate (CS), one of the major GAGs, binds to multifactorial mediators in the ECM and reportedly participates in tissue remodeling in various diseases; however, to date, its biological functions have drawn considerably less attention than other GAGs, like heparan sulfate. In the present review, we discuss the involvement and regulation of CS in tissue remodeling and pulmonary fibrotic diseases, its role in pulmonary fibrosis, and the therapeutic approaches targeting CS.

Pivotal role of dendritic cell-derived CXCL10 in the retention of T helper cell 1 lymphocytes in secondary lymph nodes.

Various immune diseases are considered to be regulated by the balance of T helper (Th)1 and Th2 subsets. Although Th lymphocytes are believed to be generated in draining lymph nodes (LNs), in vivo Th cell behaviors during Th1/Th2 polarization are largely unexplored. Using a murine granulomatous liver disease model induced by Propionibacterium acnes, we show that retention of Th1 cells in the LNs is controlled by a chemokine, CXCL10/interferon (IFN) inducible protein 10 produced by mature dendritic cells (DCs). Hepatic LN DCs preferentially produced CXCL10 to attract 5'-bromo-2'-deoxyuridine (BrdU)+CD4+ T cells and form clusters with IFN-gamma-producing CD4+ T cells by day 7 after antigen challenge. Blockade of CXCL10 dramatically altered the distribution of cluster-forming BrdU+CD4+ T cells. BrdU+CD4+ T cells in the hepatic LNs were selectively diminished while those in the circulation were significantly increased by treatment with anti-CXCL10 monoclonal antibody. This was accompanied by accelerated infiltration of memory T cells into the periphery of hepatic granuloma sites, most of them were in cell cycle and further produced higher amount of IFN-gamma leading to exacerbation of liver injury. Thus, mature DC-derived CXCL10 is pivotal to retain Th1 lymphocytes within T cell areas of draining LNs and optimize the Th1-mediated immune responses.

MIP-3alpha and MIP-1alpha rapidly mobilize dendritic cell precursors into the peripheral blood.

Acquisition of dendritic cells (DCs) or DC precursors in vitro is critical for DC-based immunotherapy. We reported previously that administration of MIP-1alpha mobilized a population of F4/80(-)B220(-)CD11c+ DC precursors into peripheral blood by the expression of CCR1 and CCR5. In this study, we identified a new subset of CCR6+CCR1(-)CCR5(-)B220(-)CD11c(+) cells in MIP-1alpha-administered mice. When cultured with GM-CSF, IL-4, and TNF-alpha, these cells differentiated into mature DCs, possessing the typical morphologic characteristics, phenotypes, and antigen-presenting function (termed CCR6+ DC precursors). Although it did not directly drive the CCR6+ DC precursors, MIP-1alpha could recruit a population of F4/80+CD11c(-) monocyte/macrophage-producing MIP-3alpha in the peripheral blood to mobilize a CCR6+ DC precursor subset of B220(-)CD11c+ DC precursors. Importantly, exogenous administration of MIP-3alpha significantly enhanced MIP-1alpha-induced mobilization of DC precursors. Moreover, these MIP-3alpha- and MIP-1alpha-mobilized DC precursors could be prepared for a DC vaccine capable of eliciting CTL responses to tumor cells, leading to tumor rejection in vitro and in vivo. Taken together, this study further demonstrates the mechanism of DC precursor mobilization induced by MIP-1alpha; that is, besides mobilizing DC precursors with CCR1 and CCR5 expressions, MIP-1alpha recruited F4/80+CD11c(-) monocyte/macrophage-producing MIP-3alpha, which finally mobilized the CCR6+ DC precursor subset to amplify the B220(-)CD11c+ DC precursor population. Furthermore, combined administration of MIP-3alpha and MIP-1alpha may be an efficient strategy for collecting a large number of DCs appropriate for immunotherapy.

Novel Targeting to XCR1+ Dendritic Cells Using Allogeneic T Cells for Polytopical Antibody Responses in the Lymph Nodes.

Vaccination strategy that induce efficient antibody responses polytopically in most lymph nodes (LNs) against infections has not been established yet. Because donor-specific blood transfusion induces anti-donor class I MHC antibody production in splenectomized rats, we examined the mechanism and significance of this response. Among the donor blood components, T cells were the most efficient immunogens, inducing recipient T cell and B cell proliferative responses not only in the spleen, but also in the peripheral and gut LNs. Donor T cells soon migrated to the splenic T cell area and the LNs, with a temporary significant increase in recipient NK cells. XCR1+ resident dendritic cells (DCs), but not XCR1- DCs, selectively phagocytosed donor class I MHC+ fragments after 1 day. After 1.5 days, both DC subsets formed clusters with recipient CD4+ T cells, which proliferated within these clusters. Inhibition of donor T cell migration or depletion of NK cells by pretreatment with pertussis toxin or anti-asialoGM1 antibody, respectively, significantly suppressed DC phagocytosis and subsequent immune responses. Three allogeneic strains with different NK activities had the same response but with different intensity. Donor T cell proliferation was not required, indicating that the graft vs. host reaction is dispensable. Intravenous transfer of antigen-labeled and mitotic inhibitor-treated allogeneic, but not syngeneic, T cells induced a polytopical antibody response to labeled antigens in the LNs of splenectomized rats. These results demonstrate a novel mechanism of alloresponses polytopically in the secondary lymphoid organs (SLOs) induced by allogeneic T cells. Donor T cells behave as self-migratory antigen ferries to be delivered to resident XCR1+ DCs with negligible commitment of migratory DCs. Allogeneic T cells may be clinically applicable as vaccine vectors for polytopical prophylactic antibody production even in asplenic or hyposplenic individuals.