101,929 research outputs found
Gammadelta T cells: novel initiators of adaptive immunity
No full textIn this review, we discuss the potential role of human gammadelta T cells in the control of adaptive immunity. Our latest findings emerged as a consequence of our working hypothesis, which predicts a close relationship between the migration control in leukocytes and their function in immune processes as diverse as hematopoiesis, initiation of adaptive immunity, and immune surveillance in peripheral tissues. Leukocyte migration control is defined by the combination of migration and adhesion receptors on their surface and the tissue distribution of the corresponding ligands. According to our hypothesis, leukocytes featuring migration receptors for homing to lymph nodes (LNs) will also display activities that preferentially take place within LNs. Following this line of thought, by showing LN-homing properties in a subset of human gammadelta T cells, we speculated that gammadelta T cells influence the initiation of T- and B-cell responses. Here, we summarize our recent data, showing that LN-homing gammadelta T cells have potent antigen-presenting cell characteristics. This unexpected finding is discussed with regards to microbial sensing by human gammadelta T cells and a possible role for these cells in anti-microbial immunity
XRD mineralogy of sediment core PS2630-5
No full textWe employ the quantitative X-ray diffraction method developed by Eberl (2003, 2004). The sediment < 2 mm are spiked by 10% by weight of zincite, milled, and the samples are scanned on a D5000 Siemens X-Ray Diffractometer between 5° and 65° 2-theta with a 0.02° step and a 2-sec count. The resulting 3000 data points are loaded into the Excel macro-program Rockjock v6 (Eberl, 2003) and the weight% of minerals in the sediment mixtures calculated against a suite of 124 "standard" mineral patterns (Eberl, 2003). Finally, the data are normalized to sum to 100
Human neutrophil clearance of bacterial pathogens triggers anti-microbial gamma delta T cell responses in early infection
No full textHuman blood Vc9/Vd2 T cells, monocytes and neutrophils share a responsiveness toward inflammatory chemokines and are rapidly recruited to sites of infection. Studying their interaction in vitro and relating these findings to in vivo observations in patients may therefore provide crucial insight into inflammatory events. Our present data demonstrate that Vc9/Vd2 T cells provide potent survival signals resulting in neutrophil activation and the release of the neutrophil chemoattractant CXCL8 (IL-8). In turn, Vc9/Vd2 T cells readily respond to neutrophils harboring phagocytosed bacteria, as evidenced by expression of CD69, interferon (IFN)-c and tumor necrosis factor (TNF)-a. This response is dependent on the ability of these bacteria to produce the microbial metabolite (E)-4-hydroxy-3-methyl-but-2-enyl pyrophosphate (HMB-PP), requires cell-cell contact of Vc9/Vd2 T cells with accessory monocytes through lymphocyte function-associated antigen-1 (LFA-1), and results in a TNF-a dependent proliferation of Vc9/Vd2 T cells. The antibiotic fosmidomycin, which targets the HMB-PP biosynthesis pathway, not only has a direct antibacterial effect on most HMB-PP producing bacteria but also possesses rapid anti-inflammatory properties by inhibiting cd T cell responses in vitro. Patients with acute peritoneal-dialysis (PD)-associated bacterial peritonitis – characterized by an excessive influx of neutrophils and monocytes into the peritoneal cavity – show a selective activation of local Vc9/Vd2 T cells by HMB-PP producing but not by HMB-PP deficient bacterial pathogens. The cd T celldriven perpetuation of inflammatory responses during acute peritonitis is associated with elevated peritoneal levels of cd T cells and TNF-a and detrimental clinical outcomes in infections caused by HMB-PP positive microorganisms. Taken together, our findings indicate a direct link between invading pathogens, neutrophils, monocytes and microbe-responsive cd T cells in early infection and suggest novel diagnostic and therapeutic approaches.Martin S. Davey, Chan-Yu Lin, Gareth W. Roberts, Sinéad Heuston, Amanda C. Brown, James A. Chess, Mark A. Toleman, Cormac G.M. Gahan, Colin Hill, Tanya Parish, John D. Williams, Simon J. Davies, David W. Johnson, Nicholas Topley, Bernhard Moser and Matthias Eber
An unconventional TRAIL to cancer therapy
No full textCellular immunotherapy offers novel, safe, and effective routes to treating cancer. However, approaches utilizing cytotoxic CD8+ T cells are hampered by the need to identify suitable target antigens that are expressed by tumor cells but not healthy tissues, and that are recognized with sufficient affinity. Most importantly, the applicability of CD8+ T-cell-based therapies is governed by the MHC restriction of tumor-specific epitopes, thereby limiting the potential benefit to patients carrying the appropriate MHC haplotype. Alternative approaches to harness the immune system against tumors exploit non-MHC-restricted γδ T cells that recognize stress-induced changes in transformed cells. A new report in this issue of the European Journal of Immunology [Eur. J. Immunol. 2013. 43: 3175–3182] shows that human γδ T cells efficiently kill lung cancer cells through recognition of the NKG2D ligand ULBP2 and secretion of soluble TRAIL. This finding provides new evidence for a TCR-independent cytotoxicity of γδ T cells and supports their promising potential for non-MHC-restricted immunotherapies
Letter, [Author unclear] to Paulina T. Merritt
No full textHandwritten letter to Paulina Merritt from an unknown author, October 1, 1876.
Sex-specific phenotypical and functional differences in peripheral human Vgamma9/Vdelta2 T cells.
No full textVgamma9/Vdelta2 T cells constitute a minor proportion of human peripheral blood T cells that can expand rapidly upon infection with microbial pathogens. Vgamma9/Vdelta2 T cell numbers change characteristically with age, rising from birth to puberty and gradually decreasing again beyond 30 years of age. In adults, female blood donors have significantly higher levels than males, implying that circulating Vgamma9/Vdelta2 T cells in women remain elevated for a longer period in life and drop less strikingly than in men. This loss in men is accompanied by a substantial depletion of CD27- CD45RA- and CD27- CD45RA+ effector T cells and a parallel increase in CD27+ CD45RA- central memory T cells while in women, the distribution of Vgamma9/Vdelta2 T cell subsets remains virtually unchanged. The phenotypical conversion in men older than 30 years is mirrored by an increased proliferative response of Vgamma9/Vdelta2 T cells and a reduced interferon-gamma secretion upon stimulation with isopentenyl pyrophosphate in vitro
XRD mineralogy of sediment core PS2640-6
No full textWe employ the quantitative X-ray diffraction method developed by Eberl (2003, 2004). The sediment < 2 mm are spiked by 10% by weight of zincite, milled, and the samples are scanned on a D5000 Siemens X-Ray Diffractometer between 5° and 65° 2-theta with a 0.02° step and a 2-sec count. The resulting 3000 data points are loaded into the Excel macro-program Rockjock v6 (Eberl, 2003) and the weight% of minerals in the sediment mixtures calculated against a suite of 124 "standard" mineral patterns (Eberl, 2003). Finally, the data are normalized to sum to 100
Thomistic Principles and Bioethics
No full textAlongside a revival of interest in Thomism in philosophy, scholars have realised its relevance when addressing certain contemporary issues in bioethics. This book offers a rigorous interpretation of Aquinas's metaphysics and ethical thought, and highlights its significance to questions in bioethics. Jason T. Eberl applies Aquinas’s views on the seminal topics of human nature and morality to key questions in bioethics at the margins of human life – questions which are currently contested in the academia, politics and the media such as: When does a human person’s life begin? How should we define and clinically determine a person’s death? Is abortion ever morally permissible? How should we resolve the conflict between the potential benefits of embryonic stem cell research and the lives of human embryos? Does cloning involve a misuse of human ingenuity and technology? What forms of treatment are appropriate for irreversibly comatose patients? How should we care for patients who experience unbearable suffering as they approach the end of life? Thomistic Principles and Bioethics presents a significant philosophical viewpoint which will motivate further dialogue amongst religious and secular arenas of inquiry concerning such complex issues of both individual and public concern
XRD mineralogy of sediment core PS2641-4
No full textWe employ the quantitative X-ray diffraction method developed by Eberl (2003, 2004). The sediment < 2 mm are spiked by 10% by weight of zincite, milled, and the samples are scanned on a D5000 Siemens X-Ray Diffractometer between 5° and 65° 2-theta with a 0.02° step and a 2-sec count. The resulting 3000 data points are loaded into the Excel macro-program Rockjock v6 (Eberl, 2003) and the weight% of minerals in the sediment mixtures calculated against a suite of 124 "standard" mineral patterns (Eberl, 2003). Finally, the data are normalized to sum to 100
XRD mineralogy of sediment core JM07-WP-174-GC
No full textWe employ the quantitative X-ray diffraction method developed by Eberl (2003, 2004). The sediment < 2 mm are spiked by 10% by weight of zincite, milled, and the samples are scanned on a D5000 Siemens X-Ray Diffractometer between 5° and 65° 2-theta with a 0.02° step and a 2-sec count. The resulting 3000 data points are loaded into the Excel macro-program Rockjock v6 (Eberl, 2003) and the weight% of minerals in the sediment mixtures calculated against a suite of 124 "standard" mineral patterns (Eberl, 2003). Finally, the data are normalized to sum to 100
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