2,188 research outputs found
Constitutive CD8 expression allows inefficient maturation of CD4+ helper T cells in class II major histocompatibility complex mutant mice.
Although mature CD4+ T cells bear T cell receptors (TCRs) that recognize class II major histocompatibility complex (MHC) and mature CD8+ T cells bear TCRs that recognize class I MHC, it is possible that the initial commitment of an immature thymocyte to a CD4 or CD8 lineage is made without regard to the specificity of the TCR. According to this model, CD4+ cells with class I TCR do not mature because the CD8 coreceptor is required for class I MHC recognition and positive selection. If this model is correct, constitutive expression of CD8 should allow CD4+ T cells with class I-specific TCRs to develop. In this report, we show that mature peripheral CD4+ cells are present in class II MHC-deficient mice that express a constitutive CD8.1 transgene. These cells share a number of properties with the major class II MHC-selected CD4 population, including the ability to express CD40 ligand upon activation. Although mature CD4 cells are also detectable in the thymus of class II MHC mutant/CD8.1 transgenic mice, they represent a small fraction of the mature CD4 cells found in mice that express class II MHC. These results indicate that some T cells choose the CD4 helper lineage independent of their antigen receptor specificity; however, the inefficiency of generating class I-specific CD4 cells leaves open the possibility that an instructive signal generated upon MHC recognition may bias lineage commitment
What Should EDA Fund? Developing a Model for Pre-Assessment of Economic Development Investments
This paper describes the completion of a “comprehensive study of regionalism” that was conducted by a joint team of economists and economic development specialists for the Economic Development Administration (EDA). The project consisted of two main activities: an examination of the factors associated with economic development success and the creation of a practical interactive tool for EDA project assessment and comparison. Findings from surveys, interviews, and project case studies are discussed in terms of their support for a positive relationship between successful economic development efforts and factors such as leadership and private investment. Also, the authors discuss the creation of a quantitative assessment model utilizing well-known approaches such as economic impact multipliers and cluster theory. The primary contribution of this work to the existing body of EDA-focused research and evaluation literature is introducing a means of using standardized scores, also known as z-scores, to compare and assess economic development projects across both industries and regions.regional economic development, economic impact, assessment model, EDA, z-score
The cytoplasmic domain of CD4 promotes the development of CD4 lineage T cells.
Thymocytes must bind major histocompatibility complex (MHC) proteins on thymic epithelial cells in order to mature into either CD8+ cytotoxic T cells or CD4+ helper T cells. Thymic precursors express both CD8 and CD4, and it has been suggested that the intracellular signals generated by CD8 or CD4 binding to class I or II MHC, respectively, might influence the fate of uncommitted cells. Here we test the notion that intracellular signaling by CD4 directs the development of thymocytes to a CD4 lineage. A hybrid protein consisting of the CD8 extracellular and transmembrane domains and the cytoplasmic domain of CD4 (CD884) should bind class I MHC but deliver a CD4 intracellular signal. We find that expression of a hybrid CD884 protein in thymocytes of transgenic mice leads to the development of large numbers of class I MHC-specific, CD4 lineage T cells. We discuss these results in terms of current models for CD4 and CD8 lineage commitment
Federalism in Campus Sexual Violence: How States Can Protect Their Students When a Trump Administration Will Not
Title IX has become shorthand for the issue of campus sexual assault. So common is Title IX attention on campus sexual violence that it is easy to forget how recently campus sexual violence was a neglected issue. Only after years of student activism did the federal government begin to address campus sexual violence. In 2014, President Obama created the White House Task Force to Protect Students from Sexual Assault. In his work on the issue, President Obama likely became the first U.S. president to even mention campus sexual violence, let alone work to combat it
Mice Infected with Low-virulence Strains of Toxoplasma gondii Lose their Innate Aversion to Cat Urine, Even after Extensive Parasite Clearance
Toxoplasma gondii chronic infection in rodent secondary hosts has been
reported to lead to a loss of innate, hard-wired fear toward cats, its primary
host. However the generality of this response across T. gondii strains and the
underlying mechanism for this pathogen mediated behavioral change remain
unknown. To begin exploring these questions, we evaluated the effects of
infection with two previously uninvestigated isolates from the three major
North American clonal lineages of T. gondii, Type III and an attenuated strain
of Type I. Using an hour-long open field activity assay optimized for this
purpose, we measured mouse aversion toward predator and non-predator urines. We
show that loss of innate aversion of cat urine is a general trait caused by
infection with any of the three major clonal lineages of parasite.
Surprisingly, we found that infection with the attenuated Type I parasite
results in sustained loss of aversion at times post infection when neither
parasite nor ongoing brain inflammation were detectable. This suggests that T.
gondii-mediated interruption of mouse innate aversion toward cat urine may
occur during early acute infection in a permanent manner, not requiring
persistence of parasitecysts or continuing brain inflammation.Comment: 14 pages, 3 figure
An Evening with Helen Whitney
Showing of a 90-minute segment of Forgiveness, a documentary film by Helen Whitney followed by a discussion of the book of the same name. Helen Whitney will be in attendance and be available to answer questions about the film and book. Dr. Patricia A. Robey will facilitate the event
Dynamic Behavior of T Cells and Thymocytes in Lymphoid Organs as Revealed by Two-Photon Microscopy
AbstractThe initial application of two-photon imaging to the study of lymphoid tissues has provided a dramatic glimpse into how cells of the immune system move and interact in their native environments. In this review we summarize what we have learned so far and point out areas for future investigation using this approach
Assessing the Feasibility of an Aerotropolis Around Cleveland Hopkins International Airport, Technical Report
This report provides an assessment of the feasibility of developing an aerotropolis around Cleveland Hopkins International Airport, Cleveland, Ohio. The report describes the methodology used to assess the feasibility, notes the needs and expectations of community stakeholders, profiles the challenges and successes of six emerging and potential U.S. aerotropolises, and discusses the operating experiences and challenges of 12 additional U.S. airports. Further, this report describes the demographic and economic aspects of the study cities, and discusses potential target industry opportunities. The findings suggest that it is feasible to develop CLE as an aerotropolis, and that CLE may not be suited for an aerotropolis as practiced at other domestic and international airports. Rather, the concept itself may be the platform for moving forward with a defined, staged strategy for development surrounding CLE and should be viewed as an opportunity to develop the concept to specifically fit the region and its economic circumstance
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