1,713 research outputs found

    Structure and specificity of T cell receptor gamma/delta on major histocompatibility complex antigen-specific CD3+, CD4-, CD8- T lymphocytes.

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    Analyses of TCR-bearing murine and human T cells have defined a unique subpopulation of T cells that express the TCR-gamma/delta proteins. The specificity of TCR-gamma/delta T cells and their role in the immune response have not yet been elucidated. Here we examine alloreactive TCR-gamma/delta T cell lines and clones that recognize MHC-encoded antigens. A BALB/c nu/nu (H-2d)-derived H-2k specific T cell line and derived clones were both cytolytic and released lymphokines after recognition of a non-classical H-2 antigen encoded in the TL region of the MHC. These cells expressed the V gamma 2/C gamma 1 protein in association with a TCR-delta gene product encoded by a Va gene segment rearranged to two D delta and one J delta variable elements. A second MHC-specific B10 nu/nu (H-2b) TCR-gamma/delta T cell line appeared to recognize a classical H-2D-encoded MHC molecule and expressed a distinct V gamma/C gamma 4-encoded protein. These data suggest that many TCR-gamma/delta-expressing T cells may recognize MHC-linked antigens encoded within distinct subregions of the MHC. The role of MHC-specific TCR-gamma/delta cells in immune responses and their immunological significance are discussed

    Expansion of Human Regulatory T-Cells From Patients With Type 1 Diabetes

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    OBJECTIVE—Regulatory T-cells (Tregs) have catalyzed the field of immune regulation. However, translating Treg-based therapies from animal models of autoimmunity to human clinical trials requires robust methods for the isolation and expansion of these cells—a need forming the basis for these studies

    Impact of sulphurous water Politzer inhalation on audiometric parameters in children with otitis media with effusion

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    Objectives: The positive effects of spa therapy on ear, nose, and throat pathology are known but robust literature in this field, is still lacking. The aim of this study was to assess through a retrospective analysis, the effects on otitis media with effusion of Politzer endotympanic inhalation of sulphurous waters in children aged 5-9 years. Methods: A cohort of 95 patients was treated with Politzer insufflations of sulphurous water: 58 patients did a cycle consisting of a treatment of 12 days per year for three consecutive years; 37 patients followed the same procedure for 5 years consecutively. The control population was represented by untreated, age-matched children. A standard audiometric test was used before and after each cycle of treatment. Results: One cycle of Politzer inhalation of sulphur-rich water improved the symptoms. Three cycles definitively stabilized the improvement of hearing function. Conclusion: Our results show that otitis media with effusion in children can be resolved by an appropriate non-pharmacological treatment of middle ear with sulphur-rich water

    Accounting for the Change in Income Disparities between US Central Cities and their Suburbs from 1980 to 1990

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    Develops a method that uses cluster analysis to group central cities in the United States. Selection of the candidate cluster solutions; Median characteristics of the clusters; Stressed central cities; Healthy central cities

    Early development of the malleus and incus in humans.

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    It is widely accepted by developmental biologists that the malleus and incus of the mammalian middle ear are first pharyngeal arch derivatives, a contention based originally on classical embryology that has now been backed up by molecular evidence from rodent models. However, it has been claimed in several studies of human ossicular development that the manubrium of the malleus and long process of the incus are actually derived from the second arch. This 'dual-arch' interpretation is commonly presented in otolaryngology textbooks, and it has been used by clinicians to explain the aetiology of certain congenital abnormalities of the human middle ear. In order to re-examine the origins of the human malleus and incus, we made three-dimensional reconstructions of the pharyngeal region of human embryos from 7 to 28 mm crown-rump length, based on serial histological sections from the Boyd Collection. We considered the positions of the developing ossicles relative to the pharyngeal pouches and clefts, and the facial and chorda tympani nerves. Confirming observations from previous studies, the primary union between first pharyngeal pouch and first cleft found in our youngest specimens was later lost, the external meatus developing rostroventral to this position. The mesenchyme of the first and second arches in these early embryos seemed to be continuous, but the boundaries of the developing ossicles proved to be very hard to determine at this stage. When first distinguishable, the indications were that both the manubrium of the malleus and the long process of the incus were emerging within the first pharyngeal arch. We therefore conclude that the histological evidence, on balance, favours the 'classical' notion that the human malleus and incus are first-arch structures. The embryological basis of congenital ossicular abnormalities should be reconsidered in this light.This is the author accepted manuscript. The final version is available from Wiley via https://doi.org/10.1111/joa.1252

    CD127 expression inversely correlates with FoxP3 and suppressive function of human CD4+ T reg cells

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    Regulatory T (T reg) cells are critical regulators of immune tolerance. Most T reg cells are defined based on expression of CD4, CD25, and the transcription factor, FoxP3. However, these markers have proven problematic for uniquely defining this specialized T cell subset in humans. We found that the IL-7 receptor (CD127) is down-regulated on a subset of CD4+ T cells in peripheral blood. We demonstrate that the majority of these cells are FoxP3+, including those that express low levels or no CD25. A combination of CD4, CD25, and CD127 resulted in a highly purified population of T reg cells accounting for significantly more cells that previously identified based on other cell surface markers. These cells were highly suppressive in functional suppressor assays. In fact, cells separated based solely on CD4 and CD127 expression were anergic and, although representing at least three times the number of cells (including both CD25+CD4+ and CD25−CD4+ T cell subsets), were as suppressive as the “classic” CD4+CD25hi T reg cell subset. Finally, we show that CD127 can be used to quantitate T reg cell subsets in individuals with type 1 diabetes supporting the use of CD127 as a biomarker for human T reg cells

    CD28/CD154 Blockade Prevents Autoimmune Diabetes by Inducing Nondeletional Tolerance After Effector T-Cell Inhibition and Regulatory T-Cell Expansion

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    OBJECTIVE—Blocking T-cell signaling is an effective means to prevent autoimmunity and allograft rejection in many animal models, yet the clinical translation of many of these approaches has not resulted in the success witnessed in experimental systems. Improved understanding of these approaches may assist in developing safe and effective means to treat disorders such as autoimmune diabetes
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