40 research outputs found
T-cell derived acetylcholine aids host defenses during enteric bacterial infection with Citrobacter rodentium.
The regulation of mucosal immune function is critical to host protection from enteric pathogens but is incompletely understood. The nervous system and the neurotransmitter acetylcholine play an integral part in host defense against enteric bacterial pathogens. Here we report that acetylcholine producing-T-cells, as a non-neuronal source of ACh, were recruited to the colon during infection with the mouse pathogen Citrobacter rodentium. These ChAT+ T-cells did not exclusively belong to one Th subset and were able to produce IFNγ, IL-17A and IL-22. To interrogate the possible protective effect of acetylcholine released from these cells during enteric infection, T-cells were rendered deficient in their ability to produce acetylcholine through a conditional gene knockout approach. Significantly increased C. rodentium burden was observed in the colon from conditional KO (cKO) compared to WT mice at 10 days post-infection. This increased bacterial burden in cKO mice was associated with increased expression of the cytokines IL-1β, IL-6, and TNFα, but without significant changes in T-cell and ILC associated IL-17A, IL-22, and IFNγ, or epithelial expression of antimicrobial peptides, compared to WT mice. Despite the increased expression of pro-inflammatory cytokines during C. rodentium infection, inducible nitric oxide synthase (Nos2) expression was significantly reduced in intestinal epithelial cells of ChAT T-cell cKO mice 10 days post-infection. Additionally, a cholinergic agonist enhanced IFNγ-induced Nos2 expression in intestinal epithelial cell in vitro. These findings demonstrated that acetylcholine, produced by specialized T-cells that are recruited during C. rodentium infection, are a key mediator in host-microbe interactions and mucosal defenses
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Global Education Handbook: Modules for Teaching Pre-School to Secondary School
This handbook was developed to assist K-12 teachers who wish to introduce a global perspective into their curriculum. The modules were developed by classroom teachers and include such topics as: Anti-bias Curriculum: A Multicultural Perspective,” “The African Influence in Puerto Rican Music,” and “Multicultural Education: An Approach through Beauty, Fashion and Art.” Organized according to grade levels, each module is divided into a series of lessons complete with objectives and a detailed description of materials and activities.
It is the purpose of the Global Education Handbook to contribute to networking within the community of educators, locally and globally. The Handbook provides examples of lesson plans and units with a global perspective for use at the pre-school, elementary, middle, and secondary grade levels. It identifies a global network of resources which is available to educators who want to bring the world into their classrooms. Included is an account of an early childhood educator in a rural elementary school in Western Massachusetts who is attempting to instill a global perspective in her curriculum. Her experiences bring to light many of the challenges which confront new and veteran educators who wish to globalize their classrooms and their schools.
The Handbook is organized into chapters according to grade level: pre-school, elementary, middle, and secondary. The material within each of these chapters was developed by teachers who implemented these global education units in their classrooms. Each unit is comprised of several lessons that have either a geographic, cultural, or issue-based focus. These resources can be used directly from the Handbook and it is hoped that they will inspire the development of other lessons and units particular to the unique needs of each educator
Demand-Side Changes and the Relative Economic Progress of Black Men: 1940-90
This article uses Census data from 1940 to 1990 to examine whether the hypotheses advanced for the absence of economic progress of black men relative to white men during the 1980s are consistent with the long-run trends. The findings indicate that skill-biased technological change explains more than changes in industrial composition both in the long run as well as in the 1980s. Moreover, increased competition from women and immigrants does not explain the recent slowed progress of black men; instead, the evidence suggests that middle-skilled white men may be an important source of increased competition.
Real Wealth Changes from 1982 to 1991 Among the Newly Retired
This paper studies rates of saving and consumption among the recently retired during the 1980s. It also documents outlays associated with the death of a spouse to find the causes of wealth loss at widowhood.
Correlations of cibarial muscle activities of Homalodisca spp. sharpshooters (Hemiptera: Cicadellidae) with EPG ingestion waveform and excretion
International audienceFluid flow into and out of the stylets of xylem-ingesting sharpshooters (Hemiptera: Cicadellidae: Cicadellinae) is powered by muscles of the cibarial pump. Such fluid flow is crucial for transmission of Xylella fastidiosa, the Pierce’s Disease bacterium, yet has not been rigorously studied via electrical penetration graph (EPG) technology. We correlated EPG waveforms with electromyographically (EMG) recorded muscle potentials from the cibarial dilator muscles, which power the piston-like cibarial diaphragm. There was a 1:1 correspondence of each cycle of cibarial muscle contraction/relaxation with each plateau of EPG waveform C. Results definitively showed that the C waveform represents active ingestion, i.e. fluid flow is propelled by cibarial muscle contraction. Moreover, each C waveform episode represents muscular diaphragm uplift, probably combined with a “bounce” from cuticular elasticity, to provide the suction that pulls fluid into the stylets. Fine structure of the EPG ingestion waveform represents directionality of fluid flow, supporting the primary role of streaming potentials as the electrical origin of the C waveform. Rhythmic bouts of cibarial pumping were generally correlated with sustained production of excretory droplets. However, neither the onset nor cessation of ingestion was correlated with onset or cessation of excretion, respectively. Volume of excreta is an inexact measure of ingestion. Implications for using EPG to understand the mechanism of X. fastidiosa transmission are discusse
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Neuroanatomy of the spleen: Mapping the relationship between sympathetic neurons and lymphocytes.
The nervous system plays a profound regulatory role in maintaining appropriate immune responses by signaling to immune cells. These immune cells, including B- and T-cells, can further act as intermediary messengers, with subsets of B- and T-cells expressing choline acetyltransferase (ChAT), the enzyme required for acetylcholine (ACh) synthesis. Neural control of ACh release from ChAT+ T-cells can have powerful immune implications, regulating lymphocyte trafficking, inflammation, and prevent death due to experimental septic shock. Although ACh release from T-cells has been proposed to occur following norepinephrine (NE) released from sympathetic nerve terminals in the spleen, it is unknown how this communication occurs. While it was proposed that tyrosine hydroxylase (TH+) axons form synapse-like structures with ChAT+ T-cells, there is scant evidence to support or refute this phenomenon. With this in mind, we sought to determine the relative abundance of ChAT+ B- and T-cells in close proximity to TH+ axons, and determine what factors contribute to their localization in the spleen. Using confocal microscopy of tissue sections and three-dimensional imaging of intact spleen, we confirmed that ChAT+ B-cells exceed the number of ChAT+ T-cells, and overall few ChAT+ B- or T-cells are located close to TH+ fibers compared to total numbers. The organized location of ChAT+ lymphocytes within the spleen suggested that these cells were recruited by chemokine gradients. We identified ChAT+ B- and T-cells express the chemokine receptor CXCR5; indicating that these cells can respond to CXCL13 produced by stromal cells expressing the β2 adrenergic receptor in the spleen. Our findings suggest that sympathetic innervation contributes to organization of ChAT+ immune cells in the white pulp of the spleen by regulating CXCL13. Supporting this contention, chemical sympathectomy significantly reduced expression of this chemokine. Together, we demonstrated that there does not appear to be a basis for synaptic neuro-immune communication, and that sympathetic innervation can modulate immune function through altering stromal cell chemokine production