Toll-like Receptors 2 and 9 Are Important for Innate Immune Cell Activation and Recruitment in Hypersensitivity Pneumonitis

Hypersensitivity pneumonitis (HP) is an interstitial lung disease caused by repeated inhalation of environmental antigens. The disease is characterized by alveolitis and granuloma formation; however, some patients develop chronic HP (CHP), a restrictive lung disease characterized by fibrosis. Previous studies revealed that neutrophils are recruited into the lung via a MyD88- dependent pathway and regulate disease severity through cytokine production. Toll-like receptors (TLRs) 2 and 9 recognize conserved molecular patterns present in bacteria, and signal through the adaptor molecule MyD88. The goal of my project is to investigate the role of TLRs 2 and 9 in the pathogenesis of HP during the acute phase, granulomatous phase, and chronic phase of the disease. Using the S. rectivirgula (SR) animal model of HP, our studies indicated that individually, TLRs 2 and 9 contributed to neutrophil recruitment. We generated TLR2/9 double knockout (TLR2/9−/− ) mice to determine the extent to which TLRs 2 and 9 cooperate in neutrophil recruitment during HP. During the acute response, TLR2/9−/− mice exposed to SR demonstrated a significant reduction in neutrophil recruitment after a single exposure to SR compared to C57BL/6 mice (WT). The reduction in neutrophils was associated with a reduction in the expression of the neutrophil chemokine CXCL2 and inflammatory cytokines TNFα and IL-6 in the BALF. Disease severity in HP is associated with granuloma formation and a Th17 response. After 3 weeks exposure to SR, our results demonstrate a decrease in IL-17 and IL-22 mRNA expression and a corresponding decrease in the percentage of Th17 cells in TLR2/9−/− mice compared to WT and single knockout (SKO) mice. The decrease in Th17 cells in TLR2/9−/− mice was not associated with a significant increase in T regulatory (Treg) cells or a switch to a Th1 response. In addition, TLR2−/− and TLR2/9−/− mice have significantly fewer activated CD4+ Th cells. Interstitial macrophages from TLR2/9−/− mice have decreased costimulatory molecule and MHCII expression suggesting they are deficient in T cell activation. However, TLR2−/− , TLR9−/− , and TLR2/9−/− still form granulomas in the lung. To determine the extent to which TLRs 2 and 9 contributed to the development of CHP, WT and TLR2/9−/− mice were intranasally exposed to SR three times/week for 15 weeks. WT and TLR2/9−/− mice developed a neutrophilic and lymphocytic alveolitis, but TLR2/9−/− mice had a significant increase in eosinophils in the bronchoalveolar lavage (BAL) fluid compared to WT exposed mice. Th17 cells, but not Th2 cells were detected in the lungs of mice exposed to SR for 14 weeks, suggesting CHP is not associated with a switch to a Th2 type immune response. WT and TLR2/9−/− mice had significantly reduced static compliance compared to WT unexposed mice. To determine whether the restrictive lung defect was associated with fibrosis, we visualized collagen in the lung by histology using Masson’s trichrome stain. Measuring collagen staining by positive pixel analysis suggested TLR2/9−/− mice were partially protected from lung fibrosis compared to WT mice. Altogether, the results suggest TLRs 2 and 9 cooperate in neutrophil recruitment and subsequently disease severity and play an integral role in the outcome of HP

Brain Insulin Action Regulates Hypothalamic Glucose Sensing and the Counterregulatory Response to Hypoglycemia

The brain is the primary organ that senses blood glucose levels and initiates a stress response when blood glucose levels are too low: hypoglycemia). Insulin-dependent people with Type 1 diabetes: T1DM) have an impaired ability to sense hypoglycemia and an impaired ability to activate this counterregulatory response: CRR) to hypoglycemia. As a result, T1DM are at a greater risk of experiencing insulin induced severe hypoglycemic episodes, which can result in seizures, brain damage, or even death. Since hypoglycemia is a major barrier that limits intensive blood glucose control, important research initiatives are needed to prevent or reduce the burden of hypoglycemia for people with Type 1 diabetes, specifically by defining the mechanisms and modulators of brain glucose sensing. The experiments in this thesis were designed to investigate the role and mechanism by which insulin may regulate brain glucose sensing. Recent evidence suggests that insulin acts in the brain to regulate glucose homeostasis, central nervous system: CNS) glucose sensing, and the CRR to hypoglycemia, but the site and method of CNS insulin action are still unknown. This study 1) investigated whether insulin acts on hypothalamic neurons to regulate brain glucose sensing and 2) ascertained how insulin regulates glucose sensing by evaluating its effects on key glucose sensors and CNS glucose uptake. Taking advantage of a genetic mouse model that chronically lacks CNS insulin action: the neuronal insulin receptor knockout NIRKO mouse), this report assessed whether CNS insulin signaling regulates the brain\u27s ability to detect and respond to hypoglycemia by analyzing glucose counterregulation and neuronal activation in response to hypoglycemia. Further, to clarify a mechanism of CNS insulin action, this study assessed whether insulin regulates key glucose sensors and/or CNS glucose uptake by examining the expression patterns of key glucose sensing proteins, including glucose transporters: GLUTs) and glucokinase: GK), and measuring regional brain glucose utilization. Understanding how the brain regulates the counterregulatory response to hypoglycemia is critical to devise therapies to combat severe hypoglycemia in diabetic patients. Overall, this thesis provides new insights into insulin\u27s role in the brain to regulate CNS glucose sensing and the counterregulatory response to hypoglycemia

Climatic and eustatic controls on the development of a Late Triassic source rock in the Jameson Land Basin, East Greenland

This work was undertaken as part of the continuing work of CASP in East Greenland. The sponsoring companies are thanked for their continued support of this work. Help in the field by T. Kinnaird and useful discussions with A. Whitham are gratefully acknowledged. The reviews of L. Clemmensen and an anonymous reviewer, and the input from S. Jones led to improvements to the original paper.Peer reviewedPostprin

Solutions Network Formulation Report. Integration of OMI and TES Aerosol Products into the EPA Regional Planning Organizations' FASTNET Aerosol Tracking and Analysis Tool

Every year, more than 280 million visitors tour our Nation s most treasured parks and wilderness areas. Unfortunately, many visitors are unable to see the spectacular vistas they expect because of white or brown haze in the air. Most of this haze is not natural; it is air pollution, carried by the wind often hundreds of miles from its origin. Some of the pollutants have been linked to serious health problems, such as asthma and other lung disorders, and even premature death. In addition, nitrates and sulfates contribute to acid rain formation, which contaminates rivers and lakes and erodes buildings and historical monuments. The U.S. Environmental Protection Agency RPOs (Regional Planning Organizations) have been tasked with monitoring and determining the nature and origin of haze in Class I scenic areas, and finding ways to reduce haze in order to improve visibility in these areas. The RPOs have developed an Internet-based air quality DST (Decision Support Tool) called FASTNET (Fast Aerosol Sensing Tools for Natural Event Tracking). While FASTNET incorporates a few satellite datasets, most of the data utilized by this DST comes from ground-based instrument networks. The problem is that in many areas the sensors are sparsely located, with long distances between them, causing difficulties in tracking haze over the United States, determining its source, and analyzing its content. Satellite data could help to fill in the data gaps and to supplement and verify ground-recorded air quality data. Although satellite data are now being used for air quality research applications, such data are not routinely used for environmental decision support, in part because of limited resources, difficulties with interdisciplinary data interpretation, and the need for advanced inter-agency partnerships. As a result, the validation and verification of satellite data for air quality operational system applications has been limited This candidate solution evaluates the usefulness of OMI (Ozone Monitoring Instrument) and TES (Tropospheric Emission Spectrometer) air quality data for the RPOs by comparing OMI and TES data with ground-based data that are acquired during identified episodes of air pollution. The air quality data from OMI and TES are of different spectral ranges than data from satellites currently included in FASTNET, giving them potential advantages over the existing satellites. If the OMI and TES data are shown to be useful to the RPOs, they would then be integrated into the FASTNET DST for use on an operational basis

Molecular basis of heavy-chain class switching and switch region deletion in an Abelson virus-transformed cell line

We demonstrated that a subclone of an Abelson murine leukemia virus-transformed B-lymphoid cell line switched from mu to gamma 2b expression in vitro, by the classical recombination-deletion mechanism. In this line, the expressed VHDJH region and the C gamma 2b constant region gene were juxtaposed by a recombination event which linked the highly repetitive portions of the S mu and S gama 2b regions and resulted in the loss of the C mu gene from the intervening region. An additional recombination event in this subclone involved an internal deletion in the S mu region of the expressed (switched) allele. One end of this deletion occurred very close to the switch recombination point. Despite the recombination-deletion mechanism of switching, the gamma 2b-producing line retained two copies of the C mu gene and two copies of the sequence just 5' to the S gamma 2b recombination point. The possible significance of the retention of these sequences to the mechanism of class switching is discussed

Solutions Network Formulation Report. Reducing Light Pollution in U.S. Coastal Regions Using the High Sensitivity Cameras on the SAC-C and Aquarius/SAC-D Satellites

Light pollution has significant adverse biological effects on humans, animals, and plants and has resulted in the loss of our ability to view the stars and planets of the universe. Over half of the U.S. population resides in coastal regions where it is no longer possible to see the stars and planets in the night sky. Forty percent of the entire U.S. population is never exposed to conditions dark enough for their eyes to convert to night vision capabilities. In coastal regions, urban lights shine far out to sea where they are augmented by the output from fishing boat, cruise ship and oil platform floodlights. The proposed candidate solution suggests using HSCs (high sensitivity cameras) onboard the SAC-C and Aquarius/SAC-D satellites to quantitatively evaluate light pollution at high spatial resolution. New products modeled after pre-existing, radiance-calibrated, global nighttime lights products would be integrated into a modified Garstang model where elevation, mountain screening, Rayleigh scattering, Mie scattering by aerosols, and atmospheric extinction along light paths and curvature of the Earth would be taken into account. Because the spatial resolution of the HSCs on SAC-C and the future Aquarius/SAC-D missions is greater than that provided by the DMSP (Defense Meteorological Satellite Program) OLS (Operational Linescan System) or VIIRS (Visible/Infrared Imager/Radiometer Suite), it may be possible to obtain more precise light intensity data for analytical DSSs and the subsequent reduction in coastal light pollution