Estelle E. Newton

The Interaction among Microbiota, Immunity, and Genetic and Dietary Factors Is the Condicio Sine Qua Non Celiac Disease Can Develop

Celiac disease (CD) is an immune-mediated enteropathy, triggered by dietary wheat gluten and similar proteins of barley and rye in genetically susceptible individuals. This is a complex disorder involving both environmental and immune-genetic factors. The major genetic risk factor for CD is determined by HLA-DQ genes. Dysfunction of the innate and adaptive immune systems can conceivably cause impairment of mucosal barrier function and development of localized or systemic inflammatory and autoimmune processes. Exposure to gluten is the main environmental trigger responsible for the signs and symptoms of the disease, but exposure to gluten does not fully explain the manifestation of CD. Thus, both genetic determination and environmental exposure to gluten are necessary for the full manifestation of CD; neither of them is sufficient alone. Epidemiological and clinical data suggest that other environmental factors, including infections, alterations in the intestinal microbiota composition, and early feeding practices, might also play a role in disease development. Thus, this interaction is the condicio sine qua non celiac disease can develop. The breakdown of the interaction among microbiota, innate immunity, and genetic and dietary factors leads to disruption of homeostasis and inflammation; and tissue damage occurs. Focusing attention on this interaction and its breakdown may allow a better understanding of the CD pathogenesis and lead to novel translational avenues for preventing and treating this widespread disease.

Heat Shock Protein-90 Inhibitors Enhance Antigen Expression on Melanomas and Increase T Cell Recognition of Tumor Cells

In an effort to enhance antigen-specific T cell recognition of cancer cells, we have examined numerous modulators of antigen-expression. In this report we demonstrate that twelve different Hsp90 inhibitors (iHsp90) share the ability to increase the expression of differentiation antigens and MHC Class I antigens. These iHsp90 are active in several molecular and cellular assays on a series of tumor cell lines, including eleven human melanomas, a murine B16 melanoma, and two human glioma-derived cell lines. Intra-cytoplasmic antibody staining showed that all of the tested iHsp90 increased expression of the melanocyte differentiation antigens Melan-A/MART-1, gp100, and TRP-2, as well as MHC Class I. The gliomas showed enhanced gp100 and MHC staining. Quantitative analysis of mRNA levels showed a parallel increase in message transcription, and a reporter assay shows induction of promoter activity for Melan-A/MART-1 gene. In addition, iHsp90 increased recognition of tumor cells by T cells specific for Melan-A/MART-1. In contrast to direct Hsp90 client proteins, the increased levels of full-length differentiation antigens that result from iHsp90 treatment are most likely the result of transcriptional activation of their encoding genes. In combination, these results suggest that iHsp90 improve recognition of tumor cells by T cells specific for a melanoma-associated antigen as a result of increasing the expressed intracellular antigen pool available for processing and presentation by MHC Class I, along with increased levels of MHC Class I itself. As these Hsp90 inhibitors do not interfere with T cell function, they could have potential for use in immunotherapy of cancer.

Is capsule endoscopy appropriate for elderly patients? The influence of ageing on findings and diagnostic yield: An Italian retrospective study

BACKGROUND Few data are available on the use of capsule endoscopy in the elderly. METHODS We performed a retrospective study on 1008 consecutive patients referred to our centre between December 1, 2002 and January 30, 2014 who underwent capsule endoscopy for various indications. Patients were enrolled and divided into 3 sub-groups according to their age (Group A: <50 years; Group B: 50-69 years; Group C: >70 years). The Pillcam diagnostic yield, clinically significant findings and post-treatment outcomes were compared between groups. RESULTS Diagnostic yield was significantly higher in Group C vs. Groups A and B (65.2% vs. 42.3% and 47.5%, respectively; p<0.05). The most common diagnosis in the elderly was angiodysplasia (42.5%). In 84.5% of elderly patients (Group C) capsule endoscopy results modified patient management. CONCLUSIONS Capsule endoscopy has a high diagnostic yield and positive impact on management in patients aged >70 years.

A Screening Assay to Identify Agents That Enhance T-Cell Recognition of Human Melanomas

Although a series of melanoma differentiation antigens for immunotherapeutic targeting has been described, heterogeneous expression of antigens such as Melan-A/MART-1 and gp100 results from a loss of antigenic expression in many late stage tumors. Antigen loss can represent a means for tumor escape from immune recognition, and a barrier to immunotherapy. However, since antigen-negative tumor phenotypes frequently result from reversible gene regulatory events, antigen enhancement represents a potential therapeutic opportunity. Accordingly, we have developed a cell-based assay to screen for compounds with the ability to enhance T-cell recognition of melanoma cells. This assay is dependent on augmentation of MelanA/MART-1 antigen presentation by a melanoma cell line (MU89). T-cell recognition is detected as interleukin-2 production by a Jurkat T cell transduced to express a T-cell receptor specific for an HLA-A2 restricted epitope of the Melan-A/MART-1 protein. This cellular assay was used to perform a pilot screen by using 480 compounds of known biological activity. From the initial proof-of-principle primary screen, eight compounds were identified as positive hits. A panel of secondary screens, including orthogonal assays, was used to validate the primary hits and eliminate false positives, and also to measure the comparative efficacy of the identified compounds. This cell-based assay, thus, yields consistent results applicable to the screening of larger libraries of compounds that can potentially reveal novel molecules which allow better recognition of treated tumors by T cells.

Gut Microbiota as a Driver of Inflammation in Nonalcoholic Fatty Liver Disease

The prevalence of nonalcoholic fatty liver disease and the consequent burden of metabolic syndrome have increased in recent years. Although the pathogenesis of nonalcoholic fatty liver disease is not completely understood, it is thought to be the hepatic manifestation of the dysregulation of insulin-dependent pathways leading to insulin resistance and adipose tissue accumulation in the liver. Recently, the gut-liver axis has been proposed as a key player in the pathogenesis of NAFLD, as the passage of bacteria-derived products into the portal circulation could lead to a trigger of innate immunity, which in turn leads to liver inflammation. Additionally, higher prevalence of intestinal dysbiosis, larger production of endogenous ethanol, and higher prevalence of increased intestinal permeability and bacterial translocation were found in patients with liver injury. In this review, we describe the role of intestinal dysbiosis in the activation of the inflammatory cascade in NAFLD.

The role of "bone immunological niche" for a new pathogenetic paradigm of osteoporosis.

Osteoporosis is characterized by low bone mass and microarchitectural deterioration of bone tissue. The etiology and pathogenetic mechanisms of osteoporosis have not been clearly elucidated. Osteoporosis is linked to bone resorption by the activation of the osteoclastogenic process. The breakdown of homeostasis among pro- and antiosteoclastogenic cells causes unbalanced bone remodeling. The complex interactions among these cells in the bone microenvironment involve several mediators and proinflammatory pathways. Thus, we may consider the bone microenvironment as a complex system in which local and systemic immunity are regulated and we propose to consider it as an “immunological niche.” The study of the “bone immunological niche” will permit a better understanding of the complex cell trafficking which regulates bone resorption and disease. The goal of a perfect therapy for osteoporosis would be to potentiate good cells and block the bad ones. In this scenario, additional factors may take part in helping or hindering the proosteoblastogenic factors. Several proosteoblastogenic and antiosteoclastogenic agents have already been identified and some have been developed and commercialized as biological therapies for osteoporosis. Targeting the cellular network of the “bone immunological niche” may represent a successful strategy to better understand and treat osteoporosis and its complications.

Gut Microbiota-Immune System Crosstalk and Pancreatic Disorders

Gut microbiota is key to the development and modulation of the mucosal immune system. It plays a central role in several physiological functions, in the modulation of inflammatory signaling and in the protection against infections. In healthy states, there is a perfect balance between commensal and pathogens, and microbiota and the immune system interact to maintain gut homeostasis. The alteration of such balance, called dysbiosis, determines an intestinal bacterial overgrowth which leads to the disruption of the intestinal barrier with systemic translocation of pathogens. The pancreas does not possess its own microbiota, and it is believed that inflammatory and neoplastic processes affecting the gland may be linked to intestinal dysbiosis. Increasing research evidence testifies a correlation between intestinal dysbiosis and various pancreatic disorders, but it remains unclear whether dysbiosis is the cause or an effect. The analysis of specific alterations in the microbiome profile may permit to develop novel tools for the early detection of several pancreatic disorders, utilizing samples, such as blood, saliva, and stools. Future studies will have to elucidate the mechanisms by which gut microbiota is modulated and how it tunes the immune system, in order to be able to develop innovative treatment strategies for pancreatic disorders.

WITHDRAWN: The Role of capsule endoscopy and device assisted enteroscopy for small bowel lesions in hereditary hemorrhagic telangiectasia

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Targeted tumor therapy: turning the genome on its head

TriBiotica has combined molecular biology of cancer and proprietary chemistry to implement an innovative therapeutic approach to cancer treatment. Instead of developing immunological reagents (such as cells, antibodies or chimeric receptors) targeting antigens already present on tumor cells, the new technology produces novel structures that are not native to the tumor cell. The generation of novel molecules in a tumor-specific manner accordingly allows implementation of immunotherapeutic interventions that recognize and destroy tumor cells. Unlike immunotherapy protocols that are limited by availability of target antigens, TriBiotica’s technology utilizes the tumor’s unique transcriptome to force tumor cells to produce novel molecules that are either toxic by themselves, or allow immunotherapeutic destruction of the tumor cells without inducing toxicity against normal cells. As a proof of concept, we have used an HPV16 template from a cervical carcinoma cell to create a FLAG-tag that is uniquely assembled in HPV16 expressing tumor cells. Of the cervical cancer cell lines Caski, HeLa, and C33A, only Caski contains the HPV16 E6/E7 oncogene. Each of these lines was treated with templated assembly of bio-orthogonal compounds designed to produce FLAG tag peptide specifically in the presence of HPV16 E6/E7 mRNA. At 24 hours post-treatment, in situ production of FLAG tag in each tumor type was assayed by ELISA. The results demonstrate that FLAG tag is selectively produced in Caski cells harboring the target HPV16 template. To our knowledge, this represents the first oncogene-templated synthesis of a peptide tag within living cells. The approach offers the potential for producing a wide variety of biologically-active molecules specifically in targeted cells, leaving normal cells unaffected. This technology offers a platform that links next-generation sequencing technologies to identify genetic markers of cancers as potential targets in a vast array of tumors. Combined with genetic analyses, the therapy is adaptable to the ever-changing genetic landscape of tumors, as the same novel effector molecule can be assembled on an almost limitless array of target nucleic acid templates, so that it is possible to adapt the formation of the novel therapeutic product molecule to any target genetic templates arising from the outgrowth subsets of tumor cells. Combined with appropriate diagnostic testing, the TriBiotica technology has the potential to create a new paradigm for targeting of tumor cells that opens the door to the treatment of virtually any tumor type. The technology relies on identifying specific tumor genetic templates, and utilizing a proprietary technology that assembles novel epitopes present only in the tumor cells.