Project description:The clinical management of type 1 diabetes (T1D) faces the lack of fully predictive biomarkers and of antigen-specific therapies to prevent its development. From a therapeutic standpoint, preclinical modls of T1D have fallen short of directly translating into the human. To circumvent this limitation, we developed a new mouse model that is deficient for expression of murine major histocompatibility complex class I, class II and of murine insulin genes and instead expresses HLA-A*02:01, the high susceptibility HLA-DQ8 molecule and human insulin. The metabolic and immune phenotype of these mice is basically identical to that of the parental strains. Upon expression of B7.1 under the control of the rat insulin promoter, these mice develop T1D along with a T-lymphocyte response to human preproinsulin epitopes spanning the whole autoantigen sequence. This new model will allow evaluating peptide-based immunotherapy that may directly apply to human T1D.
Project description:To circumvent the limitations of available preclinical models for the study of type 1 diabetes (T1D), we developed a new humanized model, the YES-RIP-hB7.1 mouse. This mouse is deficient of murine major histocompatibility complex class I and class II, the murine insulin genes, and expresses as transgenes the HLA-A*02:01 allele, the diabetes high-susceptibility HLA-DQ8A and B alleles, the human insulin gene, and the human co-stimulatory molecule B7.1 in insulin-secreting cells. It develops spontaneous T1D along with CD4+ and CD8+ T-cell responses to human preproinsulin epitopes. Most of the responses identified in these mice were validated in T1D patients. This model is amenable to characterization of hPPI-specific epitopes involved in T1D and to the identification of factors that may trigger autoimmune response to insulin-secreting cells in human T1D. It will allow evaluating peptide-based immunotherapy that may directly apply to T1D in human and complete preclinical model availability to address the issue of clinical heterogeneity of human disease.
Project description:Background: Chronic exposure to inorganic arsenic (iAs) has been associated with type 2 diabetes (T2D). However, potential sex divergence and the underlying mechanisms remain understudied. iAs is not metabolized uniformly across species, which is a limitation of typical exposure studies in rodent models. The development of a new “humanized” mouse model overcomes this limitation. In this study, we leverage this model to study sex differences in the context of iAs exposure. Objectives: The aim of this study iwas to determine if males and females exhibit different liver and adipose molecular profiles and metabolic phenotypes in the context of iAs exposure. Methods: Our study was performed on wild-type (WT) 129S6/SvEvTac and humanized arsenic +3 methyl transferase (human AS3MT) 129S6/SvEvTac mice treated with 400 ppb of iAs via drinking water ad libitum. After 1 month, mice were sacrificed and the liver and epididymales gonadal adipose depot were harvested for iAs quantification as well as sequencing-based microRNA and gene expression analysis. Serum blood was collected for fasting blood glucose, fasting plasma insulin, and HOMA-IR. Results: We detected sex divergence in liver and adipose markers of diabetes (e.g., insulin signaling pathways, fasting blood glucose, fasting plasma insulin, and HOMA-IR) only in humanized (not WT) male mice. In humanized female mice, numerous genes that promote insulin sensitivity and glucose tolerance in both the liver and adipose are elevated compared to humanized male mice. We also identified Klf11 as a putative master regulator of the sex divergence in gene expression in humanized mice. Discussion: Our study underscoreds the importance of future studies leveraging the humanized mouse model to study iAs-associated metabolic disease. The findings also suggest suggested that humanized females are protected from metabolic dysfunction relative to humanized males in the context of iAs exposure. Future investigations should focus on the detailed mechanisms that underlie the sex divergence, including the potential role of miR-34a and/or Klf11.
Project description:We analysed the combined effects of exposure to maternal diabetes and disrupted HIF-1 signaling on the transcriptom in cardiac left ventricles of 12 weeks old male mice. This approach provides the information about the long term changes originating in utero due to maternal diabetes and inefficient response to hypoxia which develops as a result of hyperglycemia. The majority of changes were detected in Hif1a insufficient mice exposed to maternal diabetes.
Project description:Discoidin domain-containing receptor 1 (DDR1) plays an important role in cancer progression. However, the DDR1 function in tumors is still elusive. We recently reported that DDR1 promoted collagen fiber alignment and formation of a physical barrier, which causes immune exclusion from tumors. We also demonstrated that our DDR1 ECD-targeting mAbs can disrupt collagen fiber alignment and increase T Cell infiltration in tumors. In this study, we humanized a DDR1 ECD-targeting mAb and showed significant antitumor efficacy in an immunocompetent mouse model. We determined the binding epitope using gene mutagenesis, hydrogen-deuterium exchange mass spectrometry (HDX-MS), and X-ray crystallography. Mechanistically, we showed that the humanized mAb inhibited DDR1 phosphorylation and, more importantly, blocked DDR1 shedding and disrupted a physical barrier formed by collagen fiber alignment in tumors. This study not only paves a pathway for development of PRTH-101 as a cancer therapeutic, but also broaden our understanding of the roles of DDR1 in modulation of collagen alignments in tumor extracellular matrix and tumor immune microenvironment.
Project description:Previously, we developed a new model of diabetes-induced wound healing impairment in skin-humanized mice models that faithfully recapitulates the major histo-physiological features of such skin repair-deficient condition. Aiming to dissect the molecular mechanisms responsible for the delayed wound closure, global gene expression studies were performed.
Project description:In order to understand the mechanisms underlying diabetes mellitus, we conducted a transcriptomic profiling of the liver from Macaca fascicularis with spontaneously occurred diabetes mellitus at their middle age compared with the monkeys fed with the same food and high-fat and high-sugar diet, respectively.
Project description:Here we characterize a new animal model that spontaneously develops chronic inflammation and fibrosis in multiple organs, the non-obese diabetic inflammation and fibrosis (N-IF) mouse. In the liver, the N-IF mouse displays inflammation and fibrosis particularly evident around portal tracts and central veins and accompanied with evidence of abnormal intrahepatic bile ducts. The extensive cellular infiltration consists mainly of macrophages, granulocytes, particularly eosinophils, and mast cells. This inflammatory syndrome is mediated by a transgenic population of natural killer T cells (NKT) induced in an immunodeficient NOD genetic background. The disease is transferrable to immunodeficient recipients, while polyclonal T cells from unaffected syngeneic donors can inhibit the disease phenotype. Because of the fibrotic component, early on-set, spontaneous nature and reproducibility, this novel mouse model provides a unique tool to gain further insight into the underlying mechanisms mediating transformation of chronic inflammation into fibrosis and to evaluate intervention protocols for treating conditions of fibrotic disorders.