The Use of Rodent Models to Investigate Host-Bacteria Interactions Related to Periodontal Diseases

Even though animal models have limitations they are often superior to in vitro or clinical studies in addressing mechanistic questions and serve as an essential link between hypotheses and human patients. Periodontal disease can be viewed as a process that involves four major stages: bacterial colonization, invasion, induction of a destructive host response in connective tissue and a repair process that reduces the extent of tissue breakdown. Animal studies should be evaluated in terms of their capacity to test specific hypotheses rather than their fidelity to all aspects of periodontal disease initiation and progression. Thus, each of the models described below can be adapted to test discrete components of these four major steps, but not all of them. This review describes five different animal models that are appropriate for examining components of host-bacteria interactions that can lead to breakdown of hard and soft connective tissue or conditions that limit its repair as follows: the mouse calvarial model, murine oral gavage models with or without adoptive transfer of human lymphocytes, rat ligature model and rat Aggregatibacter actinomycetemcomitans feeding model

Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

Core-collapse supernova (CCSN) is one of the most energetic astrophysical events in the Universe. The early and prompt detection of neutrinos before (pre-SN) and during the SN burst is a unique opportunity to realize the multi-messenger observation of the CCSN events. In this work, we describe the monitoring concept and present the sensitivity of the system to the pre-SN and SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is a 20 kton liquid scintillator detector under construction in South China. The real-time monitoring system is designed with both the prompt monitors on the electronic board and online monitors at the data acquisition stage, in order to ensure both the alert speed and alert coverage of progenitor stars. By assuming a false alert rate of 1 per year, this monitoring system can be sensitive to the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos up to about 370 (360) kpc for a progenitor mass of 30$M_{\odot}$ for the case of normal (inverted) mass ordering. The pointing ability of the CCSN is evaluated by using the accumulated event anisotropy of the inverse beta decay interactions from pre-SN or SN neutrinos, which, along with the early alert, can play important roles for the followup multi-messenger observations of the next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure

Impact of opioid-free analgesia on pain severity and patient satisfaction after discharge from surgery: multispecialty, prospective cohort study in 25 countries

Background: Balancing opioid stewardship and the need for adequate analgesia following discharge after surgery is challenging. This study aimed to compare the outcomes for patients discharged with opioid versus opioid-free analgesia after common surgical procedures.Methods: This international, multicentre, prospective cohort study collected data from patients undergoing common acute and elective general surgical, urological, gynaecological, and orthopaedic procedures. The primary outcomes were patient-reported time in severe pain measured on a numerical analogue scale from 0 to 100% and patient-reported satisfaction with pain relief during the first week following discharge. Data were collected by in-hospital chart review and patient telephone interview 1 week after discharge.Results: The study recruited 4273 patients from 144 centres in 25 countries; 1311 patients (30.7%) were prescribed opioid analgesia at discharge. Patients reported being in severe pain for 10 (i.q.r. 1-30)% of the first week after discharge and rated satisfaction with analgesia as 90 (i.q.r. 80-100) of 100. After adjustment for confounders, opioid analgesia on discharge was independently associated with increased pain severity (risk ratio 1.52, 95% c.i. 1.31 to 1.76; P < 0.001) and re-presentation to healthcare providers owing to side-effects of medication (OR 2.38, 95% c.i. 1.36 to 4.17; P = 0.004), but not with satisfaction with analgesia (beta coefficient 0.92, 95% c.i. -1.52 to 3.36; P = 0.468) compared with opioid-free analgesia. Although opioid prescribing varied greatly between high-income and low- and middle-income countries, patient-reported outcomes did not.Conclusion: Opioid analgesia prescription on surgical discharge is associated with a higher risk of re-presentation owing to side-effects of medication and increased patient-reported pain, but not with changes in patient-reported satisfaction. Opioid-free discharge analgesia should be adopted routinely

Mixed Periodontal Th1-Th2 Cytokine Profile in Actinobacillus actinomycetemcomitans-Specific Osteoprotegerin Ligand (or RANK-L)- Mediated Alveolar Bone Destruction In Vivo

The Th1/Th2 cytokines involved in human periodontitis remain unclear; therefore, we established a humanized mouse model to investigate this issue in Actinobacillus actinomycetemcomitans-mediated periodontal infection. Quantitative-PCR analysis clearly demonstrates a predominantly mixed Th1 and Th2 expression profile associated with pathogen-specific cell-mediated immunity via osteoprotegerin ligand (or RANK-L)-mediated alveolar bone destruction in vivo

Analysis of the mechanism(s) of immunological tolerance to a physiological soluble antigen in transgenic mice

grantor: University of TorontoThe mammalian immune system recognizes and responds to a vast array of foreign molecules, and its diversity is generated by V-(D)-J gene recombination during ontogeny. The central feature of the immune system is self-nonself discrimination, which results in immunological reactivity or tolerance (specific immunological hyporesponsiveness to a previously encountered antigen-Ag). Breakdown of self-tolerance may result in autoimmunity to the host's own self-Ags or tissues. Recent studies have demonstrated that both central (thymus-dependent) and peripheral (extra-thymic) tolerance can operate in an Ag-specific manner by at least two major mechanisms, namely, clonal deletion (physical elimination of autoreactive lymphocytes) and clonal anergy (functional inactivation of autoreactive lymphocytes). A third mechanism, active suppression (functional inhibition of autoreactive lymphocytes), may also be of relevance, particularly for peripheral tolerance. We previously characterized the T-cell receptor repertoire specific for different insulins in Balb/c mice and identified a minimal immunogenic peptide (A chain: 1-13). These results prompted us to establish a transgenic (Tg) mouse model to study the mechanism(s) of tolerance to a soluble self-Ag under physiological conditions in vivo. These mice express the gene for a foreign Ag (beef insulin, BI, mutated from human insulin genomic DNA) under the regulatory control of its own promoter so that the Tg product is expressed in pancreatic $\beta$-islet cells. In this Tg mouse model, the functional expression of BI (range: 10\sp{-10}-10\sp{-11}M) is regulated by the host's glucose/insulin homeostasis, and is associated with a differential activation of BI-specific Th1/Th2 cells in vivo. These Tg mice are hyporesponsive to BI immunization at the level of both humoral and cell-mediated immune responses, mediated by Ag-specific T cells. Despite the level of no detectable thymic expression of the Tg products, BI-specific hyporesponsiveness may still occur in mature thymocytes of the Tg mice, suggesting the operation of a thymic selection process to a peripheral soluble Ag. Exogenous IL-2 can restore responses in peripheral T cells in vitro, suggesting also the involvement of an "anergy-inducing" mechanism. Adoptive transfer of some BI-specific CD4\sp+ Th2 cells from Tg mice into normal syngeneic Balb/c mice induced Ag-specific hyporesponsiveness (as determined by BI-specific ELISA). This in turn suggests an active suppression mechanism may be involved in the maintenance of peripheral self-tolerance. Using a transwell coculture system, it seems that the cytokine TGF-$\beta$, not IL-4 or IL-10, may be involved in suppression (but not killing or apoptosis) of Ag-specific Th1 cells. This active suppression is exerted in a bystander (Ag-specific and effector-nonspecific) fashion in vivo, and is associated with self-tolerance. The work presented in this thesis significantly extends the earlier findings in other soluble-Ag Tg model systems in which one dominant mechanism has been reported to explain the tolerance observed. Our results suggest that, at least for soluble Ags expressed peripherally: (1) self-tolerance can be accomplished both intra- and extra-thymically, and (2) there are multiple levels of regulation for self-tolerance in vivo, operating in an Ag-specific fashion, including thymic selection, peripheral anergy and active suppression. These results provide clear and important information which contribute to our understanding of the basic mechanism(s) involved in self-nonself discrimination in biological tolerance. Application of this information should improve our understanding and treatment of various diseases associated with dysregulation of immune responses, including autoimmunity, transplantation and perhaps malignancy.Ph.D

Distinct cross talk of IL‐17 & TGF‐β with the immature CD11c+TRAF6(−/−)‐null myeloid dendritic cell‐derived osteoclast precursor (mDDOCp) may engage signaling toward an alternative pathway of osteoclastogenesis for arthritic bone loss in vivo

Abstract Background Dendritic cells (DCs), though borne heterogeneous, are the most potent antigen‐presenting cells, whose critical functions include triggering antigen‐specific naïve T‐cell responses and fine‐tuning the innate versus adaptive immunity at the osteo‐immune and/or mucosal mesenchyme interface. We previously reported that immature myeloid‐CD11c+DCs/mDCs may act like osteoclast (OC) precursors (OCp/mDDOCp) capable of developing into functional OCs via an alternative pathway of inflammation‐induced osteoclastogenesis; however, what are their contribution and signaling interactions with key osteotropic cytokines (i.e., interleukin‐17 [IL‐17] and transforming growth factor‐β [TGF‐β]) to bearing such inflammatory bone loss in vivo remain unclear to date. Methods Herein, we employed mature adult bone marrow‐reconstituted C57BL/6 TRAF6(−/−)‐null chimeras without the classical monocyte/macrophage (Mo/Mϕ)‐derived OCs to address their potential contribution to OCp/mDDOCp‐mediated osteoclastogenesis in the chicken type‐II‐collagen (CC‐II)‐induced joint inflammation versus arthritic bone loss and parallel associations with the double‐positive CD11c+TRAP+TRAF6‐null(−/−) DC‐like OCs detected in vivo via the quantitative dual‐immunohistochemistry and digital histomorphometry for analyses. Results The resulting findings revealed the unrecognized novel insight that (i) immature myeloid‐CD11c+TRAF6(−/−) TRAP+DC‐like OCs were involved, co‐localized, and strongly associated with joint inflammation and bone loss, independent of the Mo/Mϕ‐derived classical OCs, in CC‐II‐immunized TRAF6(−/−)‐null chimeras, and (ii) the osteotropic IL‐17 may engage distinct crosstalk with CD11c+mDCs/mDDOCp before developing the CD11c+TRAP+TRAF6(−/−)OCs via a TGF‐β‐dependent interaction toward inflammation‐induced arthritic bone loss in vivo. Conclusion These results confirm and substantiate the validity of TRAF6(−/−)‐null chimeras to address the significance of immature mCD11c+TRAP+DC‐like OCs/mDDOCp subset for an alternative pathway of arthritic bone loss in vivo. Such CD11c+mDCs/mDDOCp‐associated osteoclastogenesis through the step‐wise twist‐in‐turns osteo‐immune cross talks are thereby theme highlighted to depict a summative re‐visitation proposed

Interleukin-10 Inhibits Gram-Negative-Microbe-Specific Human Receptor Activator of NF-κB Ligand-Positive CD4(+)-Th1-Cell- Associated Alveolar Bone Loss In Vivo

To study anti-inflammatory cytokine effects on RANKL(+)-T-cell-mediated osteoclastogenesis in vivo, we injected human interleukin-10 (hIL-10) into pathogen-infected HuPBL-NOD/SCID mice. The results show significantly decreased RANKL(+) Th1-associated alveolar bone loss and coexpression of human gamma interferon (hIFN-γ) and human macrophage colony-stimulating factor, but not hIL-4, in RANKL(+) Th cells compatible with those from successfully treated aggressive periodontitis subjects. Thus, there are critical cytokine interactions linking hIFN-γ(+) Th1 cells to RANKL-RANK/OPG signaling for periodontal osteoclastogenesis in vivo