29 research outputs found
Mast cell activation is characterized by upregulation of a functional anaphylatoxin C5a receptor
<p>Abstract</p> <p>Background</p> <p>Mast cells (MC) are key effector cells of allergic diseases and resistance to helminthic parasites and induce or amplify diverse innate and adaptive immune responses. The signals controlling MC mobilization during inflammation are not fully understood.</p> <p>Results</p> <p>Since anaphylatoxins are attractive candidates as MC chemoattractants, we investigated expression and function of anaphylatoxin receptors in murine MC. Precursor cell-derived MC cultured with IL-3 in the presence or absence of SCF did not express significant amounts of surface C5a receptor (C5aR) or C3a receptor (C3aR). MC required approximately 4 h of stimulation with Ag (DNP-albumin, following preincubation with IgE anti-DNP), ionomycin, or PMA to enable a strong chemotactic response towards C5a, paralleled by a distinct C5aR upregulation. Likewise, C5a induced intracellular calcium fluxes solely in activated MC. In contrast, C3a proved to be a weak MC chemotaxin and unable to increase intracellular calcium. Primary peritoneal MC did not express detectable amounts of anaphylatoxin receptors, however, similar to precursor cell-derived MC, stimulation with Ag or ionomycin for 4 h induced a prominent surface expression of C5aR whereas C3aR remained undetectable.</p> <p>Conclusion</p> <p>Collectively, our results suggest that Ag-dependent as well as -independent activation induces an inflammatory MC phenotype which is distinguished by neoexpression of a functional C5aR as a novel effector mechanism in MC-mediated pathogenesis.</p
EXPRESSION OF A FUNCTIONAL CHIMERIC lg-MHC CLASS II PROTEIN
composed of the a- and ß-chains of the MHC class I1
I-E molecule fused to antibody V regions derived
from anti-human CD4 mAb MT310. Expression vectors
were constructed containing the functional,
rearranged gene segments coding for the V region
domains of the antibody H and L chains in place of
the first domains of the complete structural genes
of the I-E a- and ß-chains, respectively. Celltsr ansfected
with both hybrid genes expressed a stable
protein product on the cell surface. The chimeric
molecule exhibited the idiotype of the antibody
MT310 as shown by binding to the anti-idiotypic
mAb 20-46. A protein of the anticipated molecular
mass was immunoprecipitated witha nti-mouse IgG
antiserum. Furthermore, human soluble CD4 did
bind to thetr ansfected cell line, demonstrating that
the chimeric protein possessed the binding capacity
of the original mAb. Thus, the hybrid molecule retained:
1) the properties of a MHC class I1 protein
with regardt o correct chain assembly and transport
to the cell surface: as well as 2) the Ag binding
capacity of the antibody genes used. Thgee neration
of hybrid MHC class I1 molecules with highly specific,
non-MHC-restricted bindingc apacities will be
useful for studying MHC class 11-mediated effector
functions such as selection of the T cell repertoire
in thymus of transgenic mice
Обоснование способов локализации взрывов на предприятиях
Объектом выпускной квалификационной работы является ООО "Кокс – Майнинг" Шахта "Бутовская".
Цель выпускной квалификационной работы: провести анализ существующих способов предупреждения и локализации взрывов на шахте .
В результате выполнения выпускной квалификационной работы выполнен анализ водяных, сланцевых и автоматических заслонов, была рассмотрена характеристика пластов по метану, опасность образования скоплений горючих газов и взрывов скопления метана.The object of final qualifying work is LLC "Cox - Mining" Mine "Butovskaya".
The purpose of final qualifying work: an analysis of the existing methods of prevention and localization of explosions at the mine.
As a result of final qualifying work the analysis of water, shale and automatic barriers, characteristic layers of methane, a risk of accumulations of combustible gases and methane concentrations of explosions has been considered
Activated complement C3: A potentially novel predictor of progressive IgA nephropathy
Activated complement C3: A potentially novel predictor of progressive IgA nephropathy. In the search for a serologic marker of disease activity, we measured concentrations of activated C3 (actC3, that is, neoantigens developing after C3 activation on breakdown products), C4-C3 complexes and soluble C5b-9 (sC5b-9) in one or two plasma samples from adult patients with IgA nephropathy (IgAN, N = 50) or Henoch-Schönlein purpura (HSP, N = 4). As controls, 20 patients with non-immune renal disease, but comparable age, degree of proteinuria, renal dysfunction and prevalence of hypertension were studied. Compared to controls, actC3 levels were elevated in 30% of the patients with IgAN and one of the HSP patients. C4-C3 complexes were elevated in only 8% of the IgAN patients, and sC5b-9 levels were within the control range in all IgAN and HSP patients. In IgAN patients with elevated actC3 levels, proteinuria and hematuria were more pronounced than in those with normal levels. Elevated plasma concentrations of actC3 at the first presentation correlated with subsequent deterioration of renal function both in patients with initially normal and already impaired renal function (r = -0.56, N = 44, P = 0.003). The five IgAN patients with elevated actC3 on both occasions of obtaining plasma showed the most rapid loss of renal function. We conclude that mainly alternative pathway complement activation can be demonstrated in patients with IgAN and HSP. In IgAN patients the presence of complement activation is associated with more severe renal disease. Further studies are warranted to examine the clinical usefulness of actC3 as a predictor of the subsequent course of IgAN