Barrett’s Esophagus is an increasingly common disease that is strongly associated with reflux of stomach acid and usually a hiatus hernia. Barrett’s Esophagus strongly predisposes to esophageal adenocarcinoma (EAC), a tumour with a very poor prognosis. We have undertaken the first genome-wide association study on Barrett’s Esophagus, comprising 1,852 UK cases and 5,172 UK controls in discovery and 5,986 cases and 12,825 controls in the replication. Two regions were associated with disease risk: chromosome 6p21, rs9257809 (Pcombined=4.09×10−9, OR(95%CI) =1.21(1.13-1.28)) and chromosome 16q24, rs9936833 (Pcombined=2.74×10−10, OR(95%CI) =1.14(1.10-1.19)). The top SNP on chromosome 6p21 is within the major histocompatibility complex, and the closest protein-coding gene to rs9936833 on chromosome 16q24 is FOXF1, which is implicated in esophageal development and structure. We found evidence that the genetic component of Barrett’s Esophagus is mediated by many common variants of small effect and that SNP alleles predisposing to obesity also increase risk for Barrett’s Esophagus.

Cosmetics Europe, the European Trade Association for the cosmetics and personal care industry, is conducting a multi-phase program to develop regulatory accepted, animal-free testing strategies enabling the cosmetics industry to conduct safety assessments. Based on a systematic evaluation of test methods for skin sensitization, five non-animal test methods (DPRA (Direct Peptide Reactivity Assay), KeratinoSens, h-CLAT (human cell line activation test), U-SENS, SENS-IS) were selected for inclusion in a comprehensive database of 128 substances. Existing data were compiled and completed with newly generated data, the latter amounting to one-third of all data. The database was complemented with human and local lymph node assay (LLNA) reference data, physicochemical properties and use categories, and thoroughly curated. Focused on the availability of human data, the substance selection resulted nevertheless resulted in a high diversity of chemistries in terms of physico-chemical property ranges and use categories. Predictivities of skin sensitization potential and potency, where applicable, were calculated for the LLNA as compared to human data and for the individual test methods compared to both human and LLNA reference data. In addition, various aspects of applicability of the test methods were analyzed. Due to its high level of curation, comprehensiveness, and completeness, we propose our database as a point of reference for the evaluation and development of testing strategies, as done for example in the associated work of Kleinstreuer et al. We encourage the community to use it to meet the challenge of conducting skin sensitization safety assessment without generating new animal data.

Skin sensitization is a toxicity endpoint of widespread concern, for which the mechanistic understanding and concurrent necessity for non-animal testing approaches have evolved to a critical juncture, with many available options for predicting sensitization without using animals. Cosmetics Europe and the National Toxicology Program Interagency Center for the Evaluation of Alternative Toxicological Methods collaborated to analyze the performance of multiple non-animal data integration approaches for the skin sensitization safety assessment of cosmetics ingredients. The Cosmetics Europe Skin Tolerance Task Force (STTF) collected and generated data on 128 substances in multiple in vitro and in chemico skin sensitization assays selected based on a systematic assessment by the STTF. These assays, together with certain in silico predictions, are key components of various non-animal testing strategies that have been submitted to the Organization for Economic Cooperation and Development as case studies for skin sensitization. Curated murine local lymph node assay (LLNA) and human skin sensitization data were used to evaluate the performance of six defined approaches, comprising eight non-animal testing strategies, for both hazard and potency characterization. Defined approaches examined included consensus methods, artificial neural networks, support vector machine models, Bayesian networks, and decision trees, most of which were reproduced using open source software tools. Multiple non-animal testing strategies incorporating in vitro, in chemico, and in silico inputs demonstrated equivalent or superior performance to the LLNA when compared to both animal and human data for skin sensitization.

The present publication surveys several applications of in silico (i.e., computational) toxicology approaches across different industries and institutions. It highlights the need to develop standardized protocols when conducting toxicity-related predictions. This contribution articulates the information needed for protocols to support in silico predictions for major toxicological endpoints of concern (e.g., genetic toxicity, carcinogenicity, acute toxicity, reproductive toxicity, developmental toxicity) across several industries and regulatory bodies. Such novel in silico toxicology (IST) protocols, when fully developed and implemented, will ensure in silico toxicological assessments are performed and evaluated in a consistent, reproducible, and well-documented manner across industries and regulatory bodies to support wider uptake and acceptance of the approaches. The development of IST protocols is an initiative developed through a collaboration among an international consortium to reflect the state-of-the-art in in silico toxicology for hazard identification and characterization. A general outline for describing the development of such protocols is included and it is based on in silico predictions and/or available experimental data for a defined series of relevant toxicological effects or mechanisms. The publication presents a novel approach for determining the reliability of in silico predictions alongside experimental data. In addition, we discuss how to determine the level of confidence in the assessment based on the relevance and reliability of the information.

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Allergic contact dermatitis (ACD) is driven by the activation and proliferation of allergen-specific memory T-lymphocytes and is currently diagnosed by patch testing with a selected panel of chemical allergens. The lymphocyte transformation test (LTT) can be used to monitor ex vivo T-lymphocyte responses to antigens, including contact allergens. The LTT is not viewed as being an alternative to patch testing, but it does seek to reflect experimentally skin sensitization to specific chemicals. The LTT is based on stimulation in vitro of antigendriven T-lymphocyte proliferation. That is, exposure in culture of primed memory T-lymphocytes to the relevant antigen delivered in an appropriate configuration will provoke a secondary response that reflects the acquisition of skin sensitization. The technical aspects of this test and the utility of the approach for investigation of immune responses to contact allergens in humans are reviewed here, with particular emphasis on further development and refinement of the protocol. An important potential application is that it may provide a basis for characterizing those aspects of T-lymphocyte responses to contact allergens that have the greatest influence on skin sensitizing potency and this will be considered in some detail.

MI-HSA is able to induce secondary responses in lymphocytes drawn from sensitized subjects, and provides a more effective source of antigen than free MI. Furthermore, individual donors show differential activity profiles with respect to T lymphocyte subsets.

Summary Ulcerative colitis (UC) involves inappropriate mucosal immune responses to intestinal microbiota. Gut dendritic cells (DC