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2.
Rheumatol Int ; 42(3): 485-492, 2022 03.
Article de Anglais | MEDLINE | ID: mdl-33782747

RÉSUMÉ

Diffuse alveolar hemorrhage (DAH) is a rare but potentially life-threatening emergency that has both immune and non-immune etiologies. The objective of this investigation was to compare the risk factors and outcomes of immune and non-immune causes of DAH at a tertiary-care academic center. This was a retrospective observational study conducted at a University center. We reviewed all chest radiographs spanning 12 years (2007-2019) at our institute with the words "diffuse alveolar hemorrhage" in the body of their report, and ascertained cases of DAH through a detailed chart review. We used Chi-squared test to determine the differences in risk factors and outcomes between immune versus non-immune causes of DAH. We performed logistic regressions to assess whether baseline demographics and clinical features influence four critical outcomes: death, shock, renal failure, and severe anemia requiring transfusions. Over the 12-year period, there were 88 patients with DAH, 55 with non-immune and 33 with immune etiologies. Among immune causes of DAH, granulomatosis with polyangiitis (GPA) (10.2%), microscopic polyangiitis (MPA) (9%) and systemic lupus erythematosus (SLE) (9%) were most common. Among non-immune causes of DAH, coagulopathy (6.8%), decompensated heart failure (4.5%) and infection (3.4%) were most common. Patients with non-immune causes of DAH were 45.8% more likely to die and 20.7% less likely to experience sustained remission (p = 0.001). Patient with immune causes of DAH were 21% more likely to have extra-pulmonary findings and 23.7% more likely to have received hemodialysis (HD). The presence of extra-pulmonary findings was statistically significantly correlated with the number of blood products received, the need for HD and non-statistically significantly correlated with likelihood of death. Patients with immune causes of DAH were 71.5% more likely to receive multimodal therapy including corticosteroids. Immune-mediated DAH is associated with a better prognosis than non-immune DAH, despite its greater association with extra-pulmonary findings and requirement for hemodialysis.


Sujet(s)
Granulomatose avec polyangéite/complications , Défaillance cardiaque/complications , Hémorragie/étiologie , Lupus érythémateux disséminé/complications , Adulte , Sujet âgé , Femelle , Hémorragie/imagerie diagnostique , Humains , Mâle , Adulte d'âge moyen , Études rétrospectives , Facteurs de risque
3.
J Family Med Prim Care ; 10(11): 4017-4022, 2021 Nov.
Article de Anglais | MEDLINE | ID: mdl-35136761

RÉSUMÉ

BACKGROUND AND AIM: To evaluate and compare the efficacy of external cold and a vibrating device in reducing the pain and anxiety amidst children receiving maxillary infiltration anaesthesia over conventional methods. METHOD: A sum of thirty subjects aged between 5 and 10 years who had undergone dental procedures requiring maxillary infiltration were enrolled in the current split-mouth randomised control study. The control intervention constitutes infiltration of 1.8 mL of 2% lignocaine in addition to 1:100,000 adrenaline (Lox, Neon Laboratories Mumbai, India) whereas, the experimental group used external cold and a vibrating device (Buzzy®, MMJ Labs, Atlanta, GA, USA) in annexation to the control protocol. Simultaneous to LA administration, pulse rate was employed as an objective measure and the subjective measure was recorded using RMS Pictorial Scale (RMS-PS) for the child's discomfort. To document the child's pain as anticipated by the dentist the revised face, limbs, arms, cry and consolability (FLACC-R) scale was employed. RESULT: Lower pain sensation and anxiety was recorded in the experimental group using Buzzy when compared to control. CONCLUSION: External cold in adjacent with vibrations might be efficient in lowering pain as well as anxiety in children experiencing infiltration dental anaesthesia though further research work is requisite with a larger sample size.

5.
Epidemiol Infect ; 145(9): 1898-1909, 2017 07.
Article de Anglais | MEDLINE | ID: mdl-28367767

RÉSUMÉ

An outbreak of influenza A(H1N1)pdm09 was detected during the ongoing community-based surveillance of influenza-like illness (ILI). Among reported 119 influenza A(H1N1)pdm09 cases (59 cases in the year 2012 and 60 cases in 2015) in summer months, common clinical features were fever (100%), cough (90·7%), sore throat (85·7%), nasal discharge (48·7%), headache (55·5%), fatigue (18·5%), breathlessness (3·4%), and ear discharge (1·7%). Rise in ILI cases were negatively correlated with the seasonal factors such as relative humidity (Karl Pearson's correlation coefficient, i.e. r = -0·71 in the year 2012 and r = -0·44 in the year 2015), while rise in ILI cases were positively correlated with the temperature difference (r = 0·44 in the year 2012 and r = 0·77 in the year 2015). The effective reproduction number R, was estimated to be 1·30 in 2012 and 1·64 in 2015. The study highlights the rise in unusual influenza activity in summer month with high attack rate of ILI among children aged ⩽9 years. Children in this age group may need special attention for influenza vaccination. Influenza A(H1N1)pdm09 outbreak was confirmed in inter-seasonal months during the surveillance of ILI in Pune, India, 2012-2015.


Sujet(s)
Climat , Épidémies de maladies , Sous-type H1N1 du virus de la grippe A/physiologie , Grippe humaine/épidémiologie , Grippe humaine/virologie , Oséltamivir/pharmacologie , Adolescent , Adulte , Sujet âgé , Sujet âgé de 80 ans ou plus , Antiviraux/pharmacologie , Enfant , Enfant d'âge préscolaire , Femelle , Hémagglutinines virales/génétique , Humains , Inde/épidémiologie , Nourrisson , Nouveau-né , Sous-type H1N1 du virus de la grippe A/classification , Sous-type H1N1 du virus de la grippe A/immunologie , Mâle , Adulte d'âge moyen , Phylogenèse , ARN viral/analyse , Saisons , Analyse de séquence d'ARN , Jeune adulte
6.
Technology (Singap World Sci) ; 3(1): 1-26, 2015 Mar.
Article de Anglais | MEDLINE | ID: mdl-26167518

RÉSUMÉ

The liver performs many key functions, the most prominent of which is serving as the metabolic hub of the body. For this reason, the liver is the focal point of many investigations aimed at understanding an organism's toxicological response to endogenous and exogenous challenges. Because so many drug failures have involved direct liver toxicity or other organ toxicity from liver generated metabolites, the pharmaceutical industry has constantly sought superior, predictive in-vitro models that can more quickly and efficiently identify problematic drug candidates before they incur major development costs, and certainly before they are released to the public. In this broad review, we present a survey and critical comparison of in-vitro liver technologies along a broad spectrum, but focus on the current renewed push to develop "organs-on-a-chip". One prominent set of conclusions from this review is that while a large body of recent work has steered the field towards an ever more comprehensive understanding of what is needed, the field remains in great need of several key advances, including establishment of standard characterization methods, enhanced technologies that mimic the in-vivo cellular environment, and better computational approaches to bridge the gap between the in-vitro and in-vivo results.

7.
Int Sch Res Notices ; 2014: 976264, 2014.
Article de Anglais | MEDLINE | ID: mdl-27382629

RÉSUMÉ

A new simple, rapid, selective and precise high performance thin layer chromatographic (HPTLC) method has been developed for simultaneous estimation of vasicine, glycyrrhizin, eugenol, and cineole in herbal cough syrup. The retention factors of vasicine, glycyrrhizin, eugenol, and cineole are 0.53, 0.44, 0.75, and 0.77, respectively. Chromatography was performed on 60F254 percolated TLC plate using n-hexane : ethyl acetate : glacial acetic acid (8.5 : 1.0 : 0.5 v/v/v). Methods are validated according to ICH guidelines and can be adopted for the routine analysis of vasicine, glycyrrhizin, eugenol and cineole in herbal cough syrup.

8.
J Indian Soc Pedod Prev Dent ; 29(4): 327-32, 2011.
Article de Anglais | MEDLINE | ID: mdl-22016319

RÉSUMÉ

An acceptable treatment approach for early childhood caries in the past may not necessarily be the best treatment option for our young patients today. Technological advances in dental materials and the approach to their use need to be considered, and the introduction of new adhesive systems, restorative materials, and the approach toward treating these teeth has yielded convincing results. Two such clinical case reports where polyethylene fibers were used as intra-canal posts and to splint the pontic fabricated with polyethylene fibers reinforced composite are reported.


Sujet(s)
Résines composites/composition chimique , Couronnes , Caries dentaires/rééducation et réadaptation , Restauration coronoradiculaire , Pulpectomie , Traitement de canal radiculaire , Enfant d'âge préscolaire , Femelle , Humains , Incisive/anatomopathologie , Mâle , Maxillaire , Attelles parodontales , Polyéthylènes , Obturation de canal radiculaire , Dent de lait/anatomopathologie
10.
J Mol Biol ; 376(4): 1060-75, 2008 Feb 29.
Article de Anglais | MEDLINE | ID: mdl-18191143

RÉSUMÉ

Lactoperoxidase (LPO) is a member of the mammalian peroxidase superfamily. It catalyzes the oxidation of thiocyanate and halides. Freshly isolated and purified samples of caprine LPO were saturated with ammonium iodide and crystallized using 20% polyethylene glycol 3350 in a hanging drop vapor diffusion setup. The structure has been determined using X-ray crystallographic method and refined to R(cryst) and R(free) factors of 0.196 and 0.203, respectively. The structure determination revealed an unexpected phosphorylation of Ser198 in LPO, which is also confirmed by anti-phosphoserine antibody binding studies. The structure is also notable for observing densities for glycan chains at all the four potential glycosylation sites. Caprine LPO consists of a single polypeptide chain of 595 amino acid residues and folds into an oval-shaped structure. The structure contains 20 well-defined alpha-helices of varying lengths including a helix, H(2a), unique to LPO, and two short antiparallel beta-strands. The structure confirms that the heme group is covalently linked to the protein through two ester linkages involving carboxylic groups of Glu258 and Asp108 and modified methyl groups of pyrrole rings A and C, respectively. The heme moiety is slightly distorted from planarity, but pyrrole ring B is distorted considerably. However, an iron atom is displaced only by 0.1 A from the plane of the heme group toward the proximal site. The substrate diffusing channel in LPO is cylindrical in shape with a diameter of approximately 6 A. Two histidine residues and six buried water molecules are connected through a hydrogen-bonded chain from the distal heme cavity to the surface of protein molecule and seemingly form the basis of proton relay for catalytic action. Ten iodide ions have been observed in the structure. Out of these, only one iodide ion is located in the distal heme cavity and is hydrogen bonded to the water molecule W1. W1 is also hydrogen bonded to the heme iron as well as to distal His109. The structure contains a calcium ion that is coordinated to seven oxygen atoms and forms a typical pentagonal bipyramidal coordination geometry.


Sujet(s)
Capra/métabolisme , Lactoperoxidase/composition chimique , Séquence d'acides aminés , Acides aminés , Animaux , Calcium/composition chimique , Cristallographie aux rayons X , Disulfures/composition chimique , Hème/composition chimique , Humains , Liaison hydrogène , Modèles moléculaires , Données de séquences moléculaires , Phosphorylation , Analyse de séquence de protéine , Sérine/métabolisme , Électricité statique , Spécificité du substrat
11.
Proc Inst Mech Eng H ; 221(2): 153-60, 2007 Feb.
Article de Anglais | MEDLINE | ID: mdl-17385569

RÉSUMÉ

Surfactants influence functions of proteins in cell signalling. Because molecular mechanisms of surfactants are poorly understood, the cationic surfactant effect on three metabolically important enzymes--L-glutamate dehydrogenase, L-lactate dehydrogenase, and L-malate dehydrogenase--were investigated at a physiologically relevant pH range (6.5-7.4). How a cationic, a non-ionic, and an anionic surfactant could differentially influence these enzymes, and how these surfactants could influence the interfacial mass transport of these enzymes across a polycarbonate membrane in a separation cell were also investigated. Provided the charge density was the same, cationic surfactants affected enzymatic activities similarly, regardless of their molecular masses. Hence, a cationic surfactant behaved similarly to a hydrophilic anionic surfactant; however, the cationic surfactant also enhanced enzymatic activity at pH 6.5 and a moderately high concentration (150 ppm). The hydrophilic surfactant enhanced enzymatic activity and the hydrophobic surfactant depressed enzymatic activity. Addition of 0.1 ppm of the hydrophilic anionic surfactant decreased the amount of enzyme permeation through the membrane, but 0.1 ppm of the non-ionic surfactant had no effect, whereas 0.1 ppm of the hydrophobic surfactant increased enzyme permeation. These results have physiological and signalling implications in nanobiotechnology.


Sujet(s)
Modèles chimiques , Oxidoreductases/composition chimique , Tensioactifs/composition chimique , Cations , Simulation numérique , Activation enzymatique , Stabilité enzymatique
12.
Anal Chem ; 78(12): 3985-96, 2006 Jun 15.
Article de Anglais | MEDLINE | ID: mdl-16771536
13.
Diabetologia ; 48(11): 2221-8, 2005 Nov.
Article de Anglais | MEDLINE | ID: mdl-16205882

RÉSUMÉ

AIMS/HYPOTHESIS: Type 1 diabetes is widely held to result from an irreversible loss of insulin-secreting beta cells. However, insulin secretion is detectable in some people with long-standing type 1 diabetes, indicating either a small population of surviving beta cells or continued renewal of beta cells subject to ongoing autoimmune destruction. The aim of the present study was to evaluate these possibilities. MATERIALS AND METHODS: Pancreatic sections from 42 individuals with type 1 diabetes and 14 non-diabetic individuals were evaluated for the presence of beta cells, beta cell apoptosis and replication, T lymphocytes and macrophages. The presence and extent of periductal fibrosis was also quantified. RESULTS: Beta cells were identified in 88% of individuals with type 1 diabetes. The number of beta cells was unrelated to duration of disease (range 4-67 years) or age at death (range 14-77 years), but was higher (p<0.05) in individuals with lower mean blood glucose. Beta cell apoptosis was twice as frequent in type 1 diabetes as in control subjects (p<0.001), but beta cell replication was rare in both groups. The increased beta cell apoptosis in type 1 diabetes was accompanied by both increased macrophages and T lymphocytes and a marked increase in periductal fibrosis (p<0.001), implying chronic inflammation over many years, consistent with an ongoing supply of beta cells. CONCLUSIONS/INTERPRETATION: Most people with long-standing type 1 diabetes have beta cells that continue to be destroyed. The mechanisms underlying increased beta cell death may involve both ongoing autoimmunity and glucose toxicity. The presence of beta cells despite ongoing apoptosis implies, by definition, that concomitant new beta cell formation must be occurring, even after long-standing type 1 diabetes. We conclude that type 1 diabetes may be reversed by targeted inhibition of beta cell destruction.


Sujet(s)
Diabète de type 1/anatomopathologie , Cellules à insuline/anatomopathologie , Pancréas/physiologie , Régénération , Adolescent , Adulte , Sujet âgé , Apoptose/physiologie , Glycémie/métabolisme , Antigènes CD3 , Études cas-témoins , Numération cellulaire , Diabète de type 1/étiologie , Femelle , Fibrose , Humains , Techniques in vitro , Macrophages/anatomopathologie , Mâle , Adulte d'âge moyen , Lymphocytes T/anatomopathologie
14.
Indian J Biochem Biophys ; 40(1): 14-21, 2003 Feb.
Article de Anglais | MEDLINE | ID: mdl-22900286

RÉSUMÉ

Lactoferrin was purified from human seminal fluid obtained from the semen bank. The purified samples were saturated with Fe3+ and crystallized by microdialysis method. The crystals belong to orthorhombic space group P21212, with a = 55.9 Angstrom. b = 97.2 Angstrom, c = 156.1 Angstrom and Z = 4. The structure was determined with molecular replacement method and refined to an R factor of 18.7% for all the data to 3.4 Angstrom resolution. The overall structure of seminal lactoferrin is similar to human colostrum lactoferrin. The amino acid sequence of seminal lactoferrin shows that it has one amino acid less than human colostrum lactoferrin and the structure of its N-terminal region is far more ordered than other lactoferrins. The structure of the iron-binding site and its immediate surroundings indicate well defined features.


Sujet(s)
Fer/métabolisme , Lactoferrine/composition chimique , Lactoferrine/métabolisme , Sperme/enzymologie , Séquence d'acides aminés , Cristallographie aux rayons X , Humains , Modèles moléculaires , Données de séquences moléculaires , Structure tertiaire des protéines , Analyse de séquence
15.
Cancer Res ; 61(24): 8851-8, 2001 Dec 15.
Article de Anglais | MEDLINE | ID: mdl-11751408

RÉSUMÉ

It has been shown that serum levels of interleukin (IL)-6 are elevated in patients with various types of cancer. However, the exact source of IL-6 in these patients and its role in tumor progression remain unclear. Here we demonstrate that the autocrine production of IL-6 by tumor cells promotes resistance of the cells to chemotherapy, a novel function of IL-6 in cancer biology. Breast cancer cells that are sensitive to drug treatment do not express IL-6, whereas high levels of IL-6 are produced by multidrug-resistant breast cancer cells. Expression of the IL-6 gene in drug-sensitive breast cancer cells increases their resistance to drug treatment by activating the CCAAT enhancer-binding protein family of transcription factors and inducing mdr1 gene expression. Thus, the autocrine production of IL-6 by tumor cells is an important factor in determining the susceptibility or resistance of these cells to drug treatment. Because tumors from some breast cancer patients contain IL-6-producing cells, it is possible that IL-6 could potentially be used as a prognostic factor for chemotherapy resistance.


Sujet(s)
Tumeurs du sein/traitement médicamenteux , Tumeurs du sein/métabolisme , Multirésistance aux médicaments/physiologie , Interleukine-6/biosynthèse , Facteurs de transcription , Glycoprotéine P/biosynthèse , Glycoprotéine P/génétique , Tumeurs du sein/génétique , Protéine bêta de liaison aux séquences stimulatrices de type CCAAT/biosynthèse , Protéine bêta de liaison aux séquences stimulatrices de type CCAAT/génétique , Protéine delta liant les séquences stimulatrices de type CCAAT , Protéines liant les séquences stimulatrices de type CCAAT/biosynthèse , Protéines liant les séquences stimulatrices de type CCAAT/génétique , Division cellulaire/physiologie , Régulation de l'expression des gènes tumoraux , Gènes MDR , Humains , Cellules cancéreuses en culture , Régulation positive
16.
Development ; 128(24): 5109-17, 2001 Dec.
Article de Anglais | MEDLINE | ID: mdl-11748146

RÉSUMÉ

The importance of mesenchymal-epithelial interactions for the proper development of the pancreas has been acknowledged since the early 1960s, even though the molecule(s) mediating this process have remained unknown. We demonstrate here that Fgf10, a member of the fibroblast growth factor family (FGFs), plays an essential role in this process. We show that Fgf10 is expressed in the mesenchyme directly adjacent to the early dorsal and ventral pancreatic epithelial buds. In Fgf10(-/-) mouse embryos, the evagination of the epithelium and the initial formation of the dorsal and ventral buds appear normal. However, the subsequent growth, differentiation and branching morphogenesis of the pancreatic epithelium are arrested; this is primarily due to a dramatic reduction in the proliferation of the epithelial progenitor cells marked by the production of the homeobox protein PDX1. Furthermore, FGF10 restores the population of PDX1-positive cells in organ cultures derived from Fgf10(-/-) embryos. These results indicate that Fgf10 signalling is required for the normal development of the pancreas and should prove useful in devising methods to expand pancreatic progenitor cells.


Sujet(s)
Facteurs de croissance fibroblastique/métabolisme , Mésoderme/physiologie , Pancréas/embryologie , Cellules souches/cytologie , Animaux , Induction embryonnaire , Cellules épithéliales/cytologie , Cellules épithéliales/physiologie , Épithélium/embryologie , Facteur de croissance fibroblastique de type 10 , Facteurs de croissance fibroblastique/génétique , Souris , Souches mutantes de souris , Techniques de culture d'organes , Pancréas/cytologie , Cellules souches/physiologie
17.
Eur J Immunol ; 31(2): 653-64, 2001 Feb.
Article de Anglais | MEDLINE | ID: mdl-11180131

RÉSUMÉ

To understand the underlying basis for the strong IL-4- and CD154-mediated Igamma1 promoter activity in Ramos 2G6 B cells, we carried out transient transfection assays with luciferase-based constructs containing approximately 2.2 kb and 500 bp of the human Igamma1 proximal promoter region. As a comparison, the corresponding regions of the human Igamma3 promoter were tested under identical conditions. We found that both Igamma1 and Igamma3 promoter constructs were activated upon transfection into Ramos B cells and that activity was significantly up-regulated by CD154 and IL-4 signals. However, the Igamma1 promoter was measurably stronger than the Igamma3 promoter with respect to both basal and induced responses. Sequence comparison revealed a divergent 36-bp region containing multiple putative transcription factor binding sites in the Igamma1 but not the Igamma3 promoter. A mutational "swap" of this sequence resulted in a marked decrease and increase in Igamma1 and Igamma3 basal and induced promoter activity, respectively. Gel retardation assays with Igamma1-specific probes revealed CREB-containing complexes that were not observed with the corresponding Igamma3 probes. Mutation of a single nucleotide in overlapping CREB sites in the Igamma1 sequence resulted in a significant decrease in basal activity with a corresponding reduction in the level of IL-4- and CD154-mediated transcription.


Sujet(s)
Protéines du sang/physiologie , Ligand de CD40/physiologie , Protéine de liaison à l'élément de réponse à l'AMP cyclique/physiologie , Immunoglobuline G/génétique , Interleukine-4/physiologie , Régions promotrices (génétique) , Facteurs de transcription/physiologie , Transcription génétique , Facteurs de transcription ATF , Séquence nucléotidique , Sites de fixation , Lignée cellulaire , Séquence conservée , Humains , Données de séquences moléculaires
18.
Immunol Res ; 24(3): 311-24, 2001.
Article de Anglais | MEDLINE | ID: mdl-11817328

RÉSUMÉ

Hyper-IgM (HIM) syndrome is a rare immunodeficiency characterized by low or absent IgG, IgA, and IgE with normal or elevated levels of IgM. This disorder can be acquired or familial with either X-linked or autosomal patterns of inheritance. The X-linked form of the disease is a consequence of mutations in the CD40 ligand (CD40L) gene that encodes a protein expressed primarily on activated CD4+ T cells. The cognate interaction between CD40L on T cells and CD40 on antigen-stimulated B cells, macrophage, and dendritic cells is critical for the development of a comprehensive immune response. The non-X-linked form of HIM syndrome is heterogeneous and appears in some cases to be a consequence of mutations in the AlD gene which encodes a B cell specific protein required for class switch recombination, somatic mutation, and germinal center formation. However, mutations in other unidentified genes are clearly the basis of the disease in a subset of patients. In this article, we review the essential features of the X-linked and non-X-linked forms of HIM syndrome and discuss the critical role the CD40:CD40L receptor-ligand pair plays in the pathogenesis of these immune deficiencies.


Sujet(s)
Antigènes CD40/métabolisme , Ligand de CD40/métabolisme , Hypergammaglobulinémie/génétique , Hypergammaglobulinémie/immunologie , Immunoglobuline M/sang , Déficits immunitaires/génétique , Déficits immunitaires/immunologie , Animaux , Lymphocytes B/immunologie , Antigènes CD40/génétique , Ligand de CD40/génétique , Modèles animaux de maladie humaine , Femelle , Liaison génétique , Humains , Commutation de classe des immunoglobulines , Mâle , Souris , Mutation , Transduction du signal , Transcription génétique , Chromosome X
19.
J Immunol ; 164(6): 2871-80, 2000 Mar 15.
Article de Anglais | MEDLINE | ID: mdl-10706672

RÉSUMÉ

To establish the underlying cause of hyper-IgM syndrome in one female patient, B cell function was examined in response to CD40- and IL-4-mediated pathways. When CD40-induced functional responses were measured in unfractionated B cells, CD80 up-regulation, de novo Cmu-Cgamma recombination, and Igamma transcription were all found to be relatively unaffected. However, CD40- and IL-4-mediated CD23 up-regulation and VDJ-Cgamma transcription were clearly diminished compared to control cells. IL-4-induced CD23 expression was measurably reduced in the CD20- population as well. These results suggested that the patient's defect is positioned downstream of CD40 contact and affects both CD40- and IL-4 signal transduction pathways. Further analysis of B cell function in CD19+ B cells revealed a clear B cell defect with respect to Igamma and mature VDJ-Cgamma transcription and IgG expression. However, under the same conditions Iepsilon transcription was relatively normal. Partial restoration of B cell function occurred if PBMC or CD19+ B cells were cultured in vitro in the presence of CD154 plus IL-4. Because addition of IL-4 to cocultures containing activated T cells failed to induce B cells to undergo differentiation, the ability of the patient's B cells to acquire a responsive phenotype correlated with receiving a sustained signal through CD40. These findings support a model in which the patient expresses an intrinsic defect that is manifested in the failure of specific genes to become transcriptionally active in response to either CD154 or IL-4 and results in a functionally unresponsive B cell phenotype.


Sujet(s)
Lymphocytes B/immunologie , Hypergammaglobulinémie/génétique , Immunoglobuline M/biosynthèse , Déficits immunitaires/génétique , Transcription génétique/immunologie , Lymphocytes B/métabolisme , Lymphocytes B/anatomopathologie , Antigène CD80/biosynthèse , Ligand de CD40 , Lignée cellulaire , Enfant d'âge préscolaire , Techniques de coculture , Femelle , Liaison génétique/immunologie , Humains , Hypergammaglobulinémie/immunologie , Commutation de classe des immunoglobulines/génétique , Régions constantes des immunoglobulines/biosynthèse , Régions constantes des immunoglobulines/génétique , Chaines lourdes des immunoglobulines/génétique , Immunoglobuline M/sang , Région variable d'immunoglobuline/génétique , Chaines epsilon des immunoglobulines/génétique , Chaines gamma des immunoglobulines/biosynthèse , Chaines gamma des immunoglobulines/génétique , Déficits immunitaires/immunologie , Interleukine-4/pharmacologie , Agranulocytes/métabolisme , Activation des lymphocytes/génétique , Glycoprotéines membranaires/biosynthèse , Récepteurs aux IgE/biosynthèse , Syndrome , Lymphocytes T/immunologie , Lymphocytes T/métabolisme , Régulation positive/génétique , Régulation positive/immunologie , Chromosome X
20.
Immunology ; 99(1): 54-61, 2000 Jan.
Article de Anglais | MEDLINE | ID: mdl-10651941

RÉSUMÉ

We report the characterization of a naturally occurring polymorphism in CD40 ligand (CD40L, CD154) expressed by activated T cells from a young female patient. This polymorphism encodes a nonconservative Gly --> Arg substitution in amino acid 219 in the extracellular, CD40 binding domain of the molecule. Studies carried out with 293 epithelial cells ectopically expressing the polymorphic protein (CD154/G219R) revealed reduced levels of binding to different anti-CD154 monoclonal antibodies (mAb) and CD40-immunoglobulin (CD40-Ig). However, recognition of the polymorphic and wild-type CD154 molecules by a polyclonal antiserum was comparable, suggesting that the polymorphism affects the ability of the protein to interact with CD40 but does not significantly alter its surface expression. To determine if reduced cross-linking of CD40 mediated decreased functional effects, three CD40-dependent properties were measured. We found that pathways leading to the induction of surface CD23, CD80, and Igamma transcription were activated in response to CD154/G219R signalling. However, the decrease in affinity for CD40 by the mutated CD154 affected the ability of CD40-Ig to efficiently interfere with the binding and effectively block induced CD80 expression. In contrast, we found that the 5c8 mAb, which recognized the polymorphic molecule to a similar extent as wild-type CD154, effectively blocked the interaction between CD154/G219R and CD40 as measured by CD80 expression. These findings suggest that naturally occurring polymorphisms in the CD154 molecule may affect the ability of CD40-mediated functions to be blocked by soluble CD40 or anti-CD154 mAb in the therapeutic treatment of disease and graft rejection.


Sujet(s)
Antigènes CD40/métabolisme , Activation des lymphocytes , Glycoprotéines membranaires/génétique , Transduction du signal , Lymphocytes T/immunologie , Antigène CD80/métabolisme , Ligand de CD40 , Techniques de coculture , Femelle , Cytométrie en flux , Humains , Glycoprotéines membranaires/métabolisme , Polymorphisme génétique , Cellules cancéreuses en culture
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