Search results for "ALPHA"
showing 10 items of 3228 documents
Antifungal steroid saponins from Dioscorea cayenensis.
2004
From the rhizomes of Dioscorea cayenensis Lam.-Holl (Dioscoreaceae), the new 26- O- beta- D-glucopyranosyl-22-methoxy-3 beta,26-dihydroxy-25( R)-furost-5-en-3- O- alpha- L-rhamnopyranosyl-(1-->4)- alpha- L-rhamnopyranosyl-(1-->4)-[ alpha- L-rhamnopyranosyl-(1-->2)]- beta- D-glucopyranoside ( 1) was isolated together with the known dioscin ( 2) and diosgenin 3- O- alpha- L-rhamnopyranosyl-(1-->4)- alpha- L-rhamnopyranosyl-(1-->4)-[ alpha- L-rhamnopyranosyl-(1-->2)]- beta- D-glucopyranoside ( 3). Their structures were established on the basis of spectral data. Compound 2 exhibited antifungal activity against the human pathogenic yeasts Candida albicans, C. glabrata and C. tropicalis (MICs of …
C4 Alpha-Chain Reference Typing Report
1990
Previously it was shown that C4A and C4B alpha-chains after separation on SDS-PAGE can provide valuable information on presence and absence, as well as the number of C4A and C4B genes expressed in an individual. All samples submitted for C4 reference typing were also subjected to C4 alpha-chain separation; the results were included in the Final C4 Reference Typing List [Complement Inflamm 1990;7:193-212]. In addition, in selected cases with assumed 'reversed antigenicity', Western blots of C4 alpha-chains with monoclonal anti-C4A and B antibodies were obtained. As a result, subtypic differences of C4B allotypes were detected by the comparison of monoclonal antibodies 1217 and 1228.
Stimulation of human T cells by microbial 'superantigens'.
1991
The enterotoxins and the TSST of S. aureus, the erythrogenic toxins A and C of S. pyogenes and a still uncharacterized exoprotein of M. arthritidis belong to a family of exotoxins that have in common a potent mitogenic activity for T lymphocytes of several species. These proteins stimulate CD4+ and C8+ T cells, as well as a fraction of gamma delta TCR-bearing T cells by cross-linking variable parts of the T cell antigen receptor with MHC class II molecules on accessory or target cells. They are functionally bivalent molecules having distinct interaction sites for variable parts of the TCR and for nonpolymorphic parts of the MHC class II molecule. For alpha beta TCR-bearing T cells the V bet…
Identification of epitopes of Mycobacterium tuberculosis 16-kDa protein recognized by human leukocyte antigen-A*0201 CD8(+) T lymphocytes.
2002
CD8(+) T cells could make an important contribution to protection against tuberculosis (TB), but the antigenic determinants recognized in the context of major histocompatibility complex class I molecules remain ill defined. Our aim was to identify nonamer peptides derived from the acr/16-kDa antigen. Two immunogenic peptides (p21-29 and p120-128) were identified by their ability to elicit cytotoxic CD8(+) T cells from juvenile patients recovering from TB. Epitope-specific recognition was demonstrated by the lysis of both Mycobacterium tuberculosis-infected and peptide-pulsed macrophages, the release of cytotoxic granules, and interferon-gamma and tumor necrosis factor-alpha production. CD8(…
Granulysin‐Dependent Killing of Intracellular and ExtracellularMycobacterium tuberculosisby Vγ9/Vδ2 T Lymphocytes
2001
Contribution of Vgamma9/Vdelta2 T lymphocytes to immune protection against Mycobacterium tuberculosis is still a matter of debate. It was reported earlier that Vgamma9/Vdelta2 T lymphocytes kill macrophages harboring live M. tuberculosis through a granule-dependent mechanism that results in killing of intracellular bacilli. This study found that Vgamma9/Vdelta2 T lymphocytes reduce the viability of both extracellular and intracellular M. tuberculosis. Granulysin and perforin, both detected in Vgamma9/Vdelta2 T lymphocytes, play a major role, which indicates that Vgamma9/Vdelta2 T lymphocytes directly contribute to a protective host response against M. tuberculosis infection.
Peritoneal Cavity is a Route for Gut-Derived Microbial Signals to Promote Autoimmunity in Non-Obese Diabetic Mice
2015
Macrophages play a crucial role in innate immune reactions, and peritoneal macrophages (PMs) guard the sterility of this compartment mainly against microbial threat from the gut. Type 1 diabetes (T1D) is an autoimmune disease in which gut microbiota and gut immune system appear to contribute to disease pathogenesis. We have recently reported elevated free radical production and increased permeability of gut epithelium in non-obese diabetic (NOD) mice. Impaired barrier function could lead to bacterial leakage to the peritoneal cavity. To explore the consequences of impaired gut barrier function on extra-intestinal immune regulation, we characterized peritoneal lavage cells from young newly w…
Mycobacterial antigen(s) induce anergy by altering TCR- and TCR/CD28-induced signalling events: insights into T-cell unresponsiveness in leprosy.
2009
Present study investigates the role of Mycobacterium leprae (M. leprae) antigens on TCR- and TCR/CD28-induced signalling leading to T-cell activation and further correlates these early biochemical events with T-cell anergy, as prevailed in advanced stages of leprosy. We observed that both whole cell lystae (WCL) and soluble fraction of M. leprae sonicate (MLSA) not only inhibited TCR, thapsigargin and ionomycin induced calcium fluxes by diminishing the opening of calcium channels, but also TCR- or TCR/CD28-induced proximal signalling events like phosphorylation of Zap-70 and protein kinase-C (PKC) activity. Study of TCR- and TCR/CD28-induced downstream signals revealed that M. leprae antige…
Overexpression of genes involved in lymphocyte activation and regulation are associated with reduced CRM-derived cardiac remodelling after STEMI
2021
Abstract Aims Lymphopenia after ST-segment elevation myocardial infarction (STEMI) correlates with deleterious cardiac consequences and worse prognosis. An in-depth examination of genes implicated in lymphocyte proliferation, activation and regulation and their association with short- and long-term cardiac structure and function is therefore of great interest. Methods Peripheral blood mononuclear cells were isolated from 10 control subjects and 64 patients with a first STEMI treated with primary percutaneous coronary intervention and submitted to cardiac magnetic resonance after 1 week and 6 months. mRNA expression of genes implicated in lymphocyte activation (CD25 and CD69) and regulation …
Inducible Co-Stimulator Null MRL-Fas lpr Mice
2005
MRL/MpJ-Tnfrsf6lpr (MRL-Faslpr) mice develop a spontaneous T cell-dependent autoimmune disease that shares features with human lupus, including fatal nephritis, systemic pathology, and autoantibodies (autoAb). The inducible co-stimulator (ICOS) is upregulated on activated T cells and modulates T cell-mediated responses. To investigate whether ICOS has an essential role in regulating autoimmune lupus nephritis and the systemic illness in MRL-Faslpr mice, ICOS null (-/-) MRL Faslpr and ICOS intact (+/+) MRL-Faslpr strains (wild-type [WT]) were generated and compared. It was determined that in ICOS-/- MRL-Faslpr as compared with the WT strain, (1) there is a significant reduction in circulatin…