Tatsuki Ueda

Pathogenicity of IgG in patients with IgG4-related disease

Objective IgG4-related disease (IgG4-RD) is a systemic disease characterised by elevated serum IgG4 and IgG4-positive lymphoplasmacytic infiltration in the affected tissues. The pathogenic role of IgGs, including IgG4, in patients with IgG4-RD, however, is unknown. Design We examined the pathogenic activity of circulating IgGs in patients with IgG4-RD by injecting their IgGs into neonatal male Balb/c mice. Binding of patient IgGs to pancreatic tissue was also analysed in an ex vivo mouse organ culture model and in tissue samples from patients with autoimmune pancreatitis (AIP). Results Subcutaneous injection of patient IgG, but not control IgG, resulted in pancreatic and salivary gland injuries. Pancreatic injury was also induced by injecting patient IgG1 or IgG4, with more destructive changes induced by IgG1 than by IgG4. The potent pathogenic activity of patient IgG1 was significantly inhibited by simultaneous injection of patient IgG4. Binding of patient IgG, especially IgG1 and IgG4, to pancreatic tissue was confirmed in both the mouse model and AIP tissue samples. Conclusions IgG1 and IgG4 from patients with IgG4-RD have pathogenic activities through binding affected tissues in neonatal mice.

Short-Term Biliary Stent Placement Contributing Common Bile Duct Stone Disappearance with Preservation of Duodenal Papilla Function.

Aims. To investigate the effect of biliary stent placement without endoscopic sphincterotomy (EST) on common bile duct stones (CBDS) disappearance and the contribution of preserving the duodenal papilla function to reduce recurrence of CBDS. Methods. Sixty-six patients admitted for acute obstructive cholangitis due to CBDS who underwent biliary stent placement without EST for 2 years from March 2011 were evaluated retrospectively. The second endoscopic retrograde cholangiopancreatography (ERCP) was performed for treatment of CBDS 3 to 4 months after the first ERCP. We estimated the rate of stone disappearance at the time of second ERCP. Results. CBDS disappearance was observed in 32 (48.5%) of 66 patients. The diameter of the bile ducts and the diameter of CBDS in patients with CBDS disappearance were significantly smaller than in those with CBDS requiring extraction (p = 0.007 and p < 0.001, resp.). Stone disappearance was evident when the diameter of bile ducts and that of CBDS were <10 and 7 mm, respectively (p = 0.002). Conclusions. Short-term stent placement without EST eliminates CBDS while preserving duodenal papilla function and may be suitable for treating CBDS in patients with nondilated bile ducts and small CBDS.

ERCP using duodenoscope for treatment of stentic pancreatojejunostomy after pancreatoduodenectomy (with video)

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Generation of TCR-Expressing Innate Lymphoid-like Helper Cells that Induce Cytotoxic T Cell-Mediated Anti-leukemic Cell Response

Summary CD4+ T helper (Th) cell activation is essential for inducing cytotoxic T lymphocyte (CTL) responses against malignancy. We reprogrammed a Th clone specific for chronic myelogenous leukemia (CML)-derived b3a2 peptide to pluripotency and re-differentiated the cells into original TCR-expressing T-lineage cells (iPS-T cells) with gene expression patterns resembling those of group 1 innate lymphoid cells. CD4 gene transduction into iPS-T cells enhanced b3a2 peptide-specific responses via b3a2 peptide-specific TCR. iPS-T cells upregulated CD40 ligand (CD40L) expression in response to interleukin-2 and interleukin-15. In the presence of Wilms tumor 1 (WT1) peptide, antigen-specific dendritic cells (DCs) conditioned by CD4-modified CD40Lhigh iPS-T cells stimulated WT1-specific CTL priming, which eliminated WT1 peptide-expressing CML cells in vitro and in vivo. Thus, CD4 modification of CD40Lhigh iPS-T cells generates innate lymphoid helper-like cells inducing bcr-abl-specific TCR signaling that mediates effectiveanti-leukemic CTL responses via DC maturation, showing potential for adjuvant immunotherapy against leukemia.

Chemokine CXCL16 mediates acinar cell necrosis in cerulein induced acute pancreatitis in mice

Severe acute pancreatitis is a lethal inflammatory disease frequently accompanied by pancreatic necrosis. We aimed to identify a key regulator in the development of pancreatic necrosis. A cytokine/chemokine array using sera from patients with acute pancreatitis (AP) revealed that serum CXCL16 levels were elevated according to the severity of pancreatitis. In a mouse model of AP, Cxcl16 expression was induced in pancreatic acini in the late phase with the development of pancreatic necrosis. Cxcl16−/− mice revealed similar sensitivity as wild-type (WT) mice to the onset of pancreatitis, but better resisted development of acinar cell necrosis with attenuated neutrophil infiltration. A cytokine array and immunohistochemistry revealed lower expression of Ccl9, a neutrophil chemoattractant, in the pancreatic acini of Cxcl16−/− mice than WT mice. Ccl9 mRNA expression was induced by stimulation with Cxcl16 protein in pancreatic acinar cells in vitro, suggesting a Cxcl16/Ccl9 cascade. Neutralizing antibody against Cxcl16 ameliorated pancreatic injury in the mouse AP model with decreased Ccl9 expression and less neutrophil accumulation. In conclusion, Cxcl16 expressed in pancreatic acini contributes to the development of acinar cell necrosis through the induction of Ccl9 and subsequent neutrophil infiltration. CXCL16 could be a new therapeutic target in AP.

Laminin 511 is a target antigen in autoimmune pancreatitis

The extracellular matrix protein laminin 511 is an autoantigen involved in the pathophysiology of autoimmune pancreatitis. Pancreatic perturbation Autoimmune pancreatitis (AIP) is difficult to diagnose and can sometimes be confused with pancreatic cancer, which presents with similar symptoms. AIP is an inflammatory disease involving elevated IgG4, but the target autoantigen(s) is unidentified. This group’s previous work pointed to the extracellular matrix, and now, Shiokawa et al. show that a truncated form of laminin 511 may be a major autoantigen in AIP. They observed that half of AIP patients they analyzed had anti–laminin 511 antibodies, which were absent in healthy controls. Patient pancreatic tissues were positive for laminin 511, and immunization of mice with this protein induced AIP-like symptoms. These results reveal an autoimmune target in this disease and one day may aid AIP diagnosis. Autoimmune pancreatitis (AIP), a major manifestation of immunoglobulin G4–related disease (IgG4-RD), is an immune-mediated disorder, but the target autoantigens are still unknown. We previously reported that IgG in patients with AIP induces pancreatic injuries in mice by binding the extracellular matrix (ECM). In the current study, we identified an autoantibody against laminin 511-E8, a truncated laminin 511, one of the ECM proteins, in patients with AIP. Anti–laminin 511-E8 IgG was present in 26 of 51 AIP patients (51.0%), but only in 2 of 122 controls (1.6%), by enzyme-linked immunosorbent assay. Because truncated forms of other laminin family members in other organs have been reported, we confirmed that truncated forms of laminin 511 also exist in human and mouse pancreas. Histologic studies with patient pancreatic tissues showed colocalization of patient IgG and laminin 511. Immunization of mice with human laminin 511-E8 induced antibodies and pancreatic injury, fulfilling the pathologic criteria for human AIP. Four of 25 AIP patients without laminin 511-E8 antibodies had antibodies against integrin α6β1, a laminin 511 ligand. AIP patients with laminin 511-E8 antibodies exhibited distinctive clinical features, as the frequencies of malignancies or allergic diseases were significantly lower in patients with laminin 511-E8 antibodies than in those without. The discovery of these autoantibodies should aid in the understanding of AIP pathophysiology and possibly improve the diagnosis of AIP.

Strategy to Treat Pancreatic Fistula Using Comprehensive EndoscopicProcedures Together with Percutaneous Methods

Objective: Pancreatic fistula (PF) is an early complication after pancreatoduodenectomy. PF occurs because of disruption to the pancreatodigestive tract anastomosis with stricture or occlusion. A strategy to treat PF using interventional methods is proposed. Methods: We treated a total of 6 patients with PF by endoscopic ultrasound (EUS)-guided or percutaneous pancreatic duct drainage. In this paper, these patients are reviewed based on the applied treatment for PF. Results: At the time of introduction to our department, all the patients, except for one, had a percutaneous drainage tube implanted prior to surgery. In 2 patients undergoing pancreatojejunostomy within 3 months of the previous surgery, percutaneous introduction of a guidewire into the anastomosed jejunum, via the disrupted anastomosis, through the percutaneous fistula and the implantation of a percutaneous jejunal tube for 6 weeks was an effective PF treatment. There were 4 patients (3 pancreatojejunostomy, 1 pancreatogastrostomy) with more than 3 months of PF, with an occluded anastomosis and the pancreatic juice flow had to be rerouted by making another pancreatodigestive tract anastomosis using percutaneous or EUS-guided puncture of the pancreatic duct. Conclusions: The optimal treatment for PF is considered to be the recanalization of the stricture or occluded anastomosis, or rerouting of the pancreatic juice flow by making another anastomosis. Considering our experiences in the treatment of PF, EUS-guided puncture of the pancreatic duct near the occluded anastomosis using a convex-type EUS endoscopy is the most preferable method to treat PF. In patients for whom it is difficult to introduce the endoscope into the afferent loop in the pancreatojejunostomy, various methods, including percutaneous approaches, are feasible to treat PF.

Pluripotent stem cells as a source for T cell research and clinical application

Recently, promising clinical outcomes of cancer immunotherapy including administration of an anti PD-1 antibody targeting for T cell reactivation has gained particular attention worldwide. Adoptive cell therapy with tumor infiltrating lymphocytes and TCR/CAR (Chimeric Antigen Receptor) transgenic T cells are also under development. Although it has become clearer that the efficacy of adoptive cell therapy correlate with the quality of infusing T cells, antigen specific T cells in patients with chronic infection and cancer have been exhausted. We have succeeded to generate rejuvenated antigen specific T cells by reprogramming to pluripotency and differentiation. In this article, we introduce fundamentals of this technology and describe its potential for adoptive cell therapy in the future.