RESUMO
Arginine was found to be completely depleted from cell-free supernates of mixed leukocyte cultures suppressed by the addition of excess macrophages. Partial reversal of macrophage-mediated suppression was accomplished by daily addition of a cocktail containing arginine and nonamino acid nutrients. Complete reversal of the suppression was accomplished by the addition of arginine and glucose to the medium and the nonadherent cells after their separation from the adherent macrophages. A marked increase in the enzyme arginase was found in macrophages that had been cultured 24 h in vitro in Eagle's minimum essential medium plus 10% fetal calf serum, in peritoneal cells activated by prior injection of thioglycollate, and in one spleen activated by a graft vs. host reaction.
Assuntos
Arginase/biossíntese , Terapia de Imunossupressão , Linfócitos/imunologia , Macrófagos/imunologia , Animais , Arginina/farmacologia , Testes Imunológicos de Citotoxicidade , Indução Enzimática , Reação Enxerto-Hospedeiro , Imunidade Celular , Macrófagos/enzimologia , Camundongos , Baço/citologia , TioglicolatosRESUMO
Lipopolysaccharide, a component of the outer membrane of Gram-negative bacteria, activates B lymphocytes and macrophages. Pertussis toxin, which inactivates several members of the G protein family of signaling components, including Gi and transducin, was found to inhibit the lipopolysaccharide-induced responses of the WEHI-231 B lymphoma cell line and the P388D1 macrophage cell line. These results, combined with the demonstration that lipopolysaccharide inhibits adenylate cyclase activity in P388D1 cells, strongly argues that lipopolysaccharide activation of cells is mediated by a Gi-like receptor-effector coupling protein.
Assuntos
Toxina Adenilato Ciclase , Linfócitos B/fisiologia , Proteínas de Ligação ao GTP/fisiologia , Lipopolissacarídeos/antagonistas & inibidores , Macrófagos/fisiologia , Toxina Pertussis , Fatores de Virulência de Bordetella/farmacologia , Anticorpos Anti-Idiotípicos/imunologia , Linhagem Celular , Relação Dose-Resposta a Droga , Escherichia coli , Imunoglobulina M/imunologia , Interleucina-1/metabolismo , Lipopolissacarídeos/imunologia , Ativação Linfocitária/efeitos dos fármacos , Ativação de Macrófagos/efeitos dos fármacosRESUMO
A novel pharmacological study of CCR3 receptor reserve in a CCR3-transfected cell (CREM3) and human eosinophils was done; functional responses measured were increases in intracellular calcium and chemotaxis. Eotaxin, eotaxin-2, monocyte chemoattractant protein-4 (MCP-4), RANTES, and MCP-3 induced similar maximal eosinophil chemotaxis, whereas MCP-3 and RANTES induced submaximal calcium responses in eosinophils compared to eotaxin, MCP-4, and eotaxin-2. This suggested a receptor reserve in the chemotaxis response. Receptor reserve was quantitated for eotaxin. Occupancy of all CCR3 receptors was required for a maximal calcium response in both CREM3 and eosinophils (reserve = 1.0 or 0.17, respectively); the stimulus-calcium response relationship was linear, indicating no receptor reserve. In contrast, in eosinophils a large receptor reserve (6.5) was found for chemotaxis, where occupancy of 15% receptors drove half-maximal responses. These studies indicate that CCR3 interacts with G-proteins that are poorly coupled to the calcium response, whereas coupling efficiency and/or amplification to the chemotaxis apparatus in human eosinophils is significantly greater.
Assuntos
Quimiocinas CC , Eosinófilos/metabolismo , Receptores de Quimiocinas/agonistas , Receptores de Quimiocinas/metabolismo , Animais , Ligação Competitiva , Cálcio/metabolismo , Sinalização do Cálcio , Linhagem Celular , Células Cultivadas , Quimiocina CCL11 , Quimiocina CCL5/metabolismo , Quimiocina CCL5/farmacologia , Fatores Quimiotáticos de Eosinófilos/metabolismo , Fatores Quimiotáticos de Eosinófilos/farmacologia , Quimiotaxia de Leucócito/efeitos dos fármacos , Citocinas/metabolismo , Citocinas/farmacologia , Relação Dose-Resposta a Droga , Eosinófilos/citologia , Eosinófilos/efeitos dos fármacos , Humanos , Ligantes , Proteínas Quimioatraentes de Monócitos/metabolismo , Proteínas Quimioatraentes de Monócitos/farmacologia , Ratos , Receptores CCR3 , Receptores de Quimiocinas/genética , Termodinâmica , TransfecçãoRESUMO
We have utilized a functional screen, inhibition of proliferation of mitogen activated lymphocytes, in an attempt to obtain monoclonal antibodies to soluble mediators of immune responses and to the receptors for such mediators. We have found that contamination of hybridoma cell lines with certain species of mycoplasma can interfere with such a screen. By consuming thymidine, mycoplasma can either mimic the effect of antibodies that inhibit lymphocyte proliferation or obscure the presence of antibodies that stimulate or enhance proliferation.
Assuntos
Anticorpos Monoclonais/análise , Hibridomas/microbiologia , Ativação Linfocitária , Mycoplasma/isolamento & purificação , Animais , Anticorpos/fisiologia , Ligação Competitiva , Linhagem Celular , Feminino , Hibridomas/imunologia , Interleucina-1/administração & dosagem , Interleucina-1/imunologia , Linfócitos/imunologia , Linfócitos/metabolismo , Linfócitos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Ratos , Timidina/metabolismoRESUMO
avWD is a rare entity that is primarily associated with lymphoproliferative disorders, most commonly with multiple myeloma, lymphoma, and the myeloproliferative diseases. Various pathogenetic mechanisms have been postulated. The most commonly seen is antibodies directed against the FVIII complex, resulting in either its accelerated destruction or its accelerated clearance by the reticuloendothelial system. There may be immunoadsorption of the FVIII complexes onto the clones of malignant cells, as has been reported in several cases, or proteolysis may be causing the peripheral destruction of the FVIII complex. Lastly, as seen in hypothyroidism, global decrease in production of the multimers also results in avWD. The treatment, in general, should be aimed at controlling the underlying disorder and at stopping any life-threatening hemorrhage. The treatment includes any or all of the following: DDAVP, cryoprecipitate, FVIII concentrates, extracorporeal immunoadsorption, and chemotherapy as needed to control the underlying disorders. The screening tests that will allow for the detection of the avWD include measurement of the bleeding time, the FVIII:C, FVIII:vWF, and the FVIII:RCoF. FVIII:C inhibitors can be demonstrated by mixing the patient plasma with normal plasma. A normal prothrombin time (PT), activated partial thromboplastin time (APTT), and thrombin time (TT) are expected. Clinically, these patients present with mucosal bleeding, and in avWD tend to have an association with lymphoproliferative malignancies. They tend to be elderly patients with no prior history of bleeding diathesis and to have negative family histories for coagulopathies. Further study of these patients is warranted, because this disorder appears to have a multifactorial etiology. Increasing our understanding of avWD may increase our understanding of congenital vWD, thus allowing us to more effectively treat all patients with von Willebrand's disease.
Assuntos
Transtornos Linfoproliferativos/complicações , Doenças de von Willebrand/etiologia , Fator VIII/imunologia , Fator VIII/uso terapêutico , Humanos , Transtornos Linfoproliferativos/imunologia , Doenças de von Willebrand/diagnóstico , Doenças de von Willebrand/imunologia , Doenças de von Willebrand/terapiaRESUMO
The postjunctional alpha(2)-adrenoceptor-mediated contractility was characterized in human saphenous vein derived from coronary artery bypass graft surgery. Human saphenous vein contracted to alpha(2)-adrenoceptor selective agonists BHT-920 (5,6,7,8-Tetrahydro-6-(2-propenyl)-4H-thiazolo[4,5-d]azepin-2-amine dihydrochloride; pD(2)=6.7+/-0.1) and UK 14,304 (5-Bromo-6-(2-imidazolin-2-ylamino)quinoxaline; pD(2)=7.2+/-0.1). BHT-920-induced contractions were inhibited by the alpha(2)-adrenoceptor antagonist yohimbine (17-Hydroxy-yohimban-16-carboxylic acid methyl ester hydrochloride; pA(2)=8.7+/-0.5), but not by the alpha(1)-adrenoceptor antagonist prazosin (1-[4-Amino-6,7-dimethoxy-2-quinazolinyl]-4-[2-furanylcarbonyl]-piperazine hydrochloride; 300 nM). In contrast, prazosin (pK(b)=7.9+/-0.2) potently antagonized contractions elicited by the alpha(1)-adrenoceptor agonist phenylephrine ((R)-3-Hydroxy-alpha-[(methylamino)methyl] benzenemethanol hydrochloride; pD(2)=4.9+/-0.1), indicating that both alpha(2)- and alpha(1)-adrenoceptor evoke human saphenous vein contractions. Functional antagonist activity estimates (pA(2) or pK(b)) obtained for the alpha-adrenoceptor antagonists ARC 239 (2-[2-(4-(2-Methoxyphenyl)piperazin-1-yl)ethyl]-4,4-dimethyl-1,3-(2H,4H)-isoquinolindione dihydrochloride), WB 4101 (2-(2,6-Dimethoxyphenoxyethyl)aminomethyl-1,4-benzodioxane hydrochloride) and HV 723 (alpha-ethyl-3,4,5-trimethoxy-alpha-(3-((2-(2-methoxyphenoxy) ethyl)amino)propyl)benzeneacetonitrile) against BHT-920-induced human saphenous vein contractions were 7.0+/-0.6, 8.3+/-0.6 and 7.7+/-0.3, respectively. The alpha(2)-adrenoceptor subtype affinities (pK(i)) obtained in recombinant human alpha(2A)-, alpha(2B)- and alpha(2C)-adrenoceptor competition binding assays were 8.6, 8.3 and 8.6 for yohimbine; 6.3, 8.4 and 7.0 for ARC 239; 8.4, 7.5 and 8.4 for WB 4101 and 7.5, 7.4 and 7.9 for HV 723, respectively. Taken together, the binding and functional antagonist activity estimates obtained in these investigations indicate that alpha(2C)-adrenoceptor is the predominant postjunctional alpha(2)-adrenoceptor subtype in human saphenous vein.
Assuntos
Agonistas alfa-Adrenérgicos/farmacologia , Antagonistas Adrenérgicos alfa/farmacologia , Receptores Adrenérgicos alfa 2/efeitos dos fármacos , Veia Safena/efeitos dos fármacos , Vasoconstrição/efeitos dos fármacos , Idoso , Idoso de 80 Anos ou mais , Animais , Azepinas/farmacologia , Tartarato de Brimonidina , Células CHO , Cricetinae , Dioxanos/farmacologia , Relação Dose-Resposta a Droga , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Quinoxalinas/farmacologia , Receptores Adrenérgicos alfa 2/fisiologia , Veia Safena/fisiologia , Vasoconstrição/fisiologia , Ioimbina/farmacologiaRESUMO
Commercially prepared 0.8% reagent red blood cells (RBCs) eliminate the need to manually dilute 3 to 5% RBCs for use in gel cards. Ortho-Clinical Diagnostics investigated twelve anti-E samples detected in MTS Anti-IgG gel cards using Ortho 3% reagent RBCs manually diluted to 0.8% in MTS Diluent 2 trade mark (MTS2) that were not detected with commercially prepared Ortho 0.8% reagent RBCs. In gel tests, using additional examples of E-positive RBCs, 22 of 26 anti- E were reactive when the cells were suspended in MTS2. Only 6 of 28 anti-E were reactive with E-positive Ortho 0.8% reagent RBCs. Five anti-E were tested in gel with five R2 R2 RBCs that had been washed and resuspended in four low-ionic-strength diluents. Fifty-eight percent of tests performed in MTS2 were positive compared to 13 to 41 percent for the other diluents. Anti-E detection also varied from 6 to 56 percent based on the donor of the RBCs. Seven anti-E were characterized by their reactvity in tube techniques and were reactive using PEG and/or ficin-treated RBCs only. As a comparison, 25 archived examples of anti-E were detected using RBCs suspended in MTS2 and Ortho 0.8% reagent RBCs. These data show that some anti-E are not detected by Ortho reagent RBCs in MTS Anti-IgG gel cards. However, these anti-E have characteristics of antibodies of questionable clinical significance.
RESUMO
1. Pig nasal mucosal strips were incubated with alpha-adrenoceptor antagonists followed by alpha2-adrenoceptor agonist concentration-response curves. 2. Contractions elicited by the alpha2-adrenoceptor agonists BHT-920 (pD2 = 6.16 +/- 0.07), UK 14,304 (pD2 = 6.89 +/- 0.13) and PGE-6201204 (pD2 = 7.12 +/- 0.21) were blocked by the alpha2-adrenoceptor antagonist yohimbine (0.1 microm). In contrast, the alpha1-adrenoceptor antagonist prazosin (0.03 microm) had no effect on the BHT-920-, UK 14,304- and PGE-6201204-induced contractions, but blocked the contractile response to the alpha(1)-adrenoceptor agonist phenylephrine (pD2 = 5.38 +/- 0.04) and the mixed alpha1- and alpha2-adrenoceptor agonist oxymetazoline (pD(2) = 6.30 +/- 0.22). 3. The alpha2-adrenoceptor antagonist yohimbine (0.01-0.1 microm, pA2 = 8.04), alpha2B/C-adrenoceptor antagonist ARC 239 (10 microm, pK(b) = 6.33 +/- 0.21), alpha2A/C-adrenoceptor antagonist WB 4101 (0.3 microm, pK(b) = 8.01 +/- 0.24), alpha2A-adrenoceptor antagonists BRL44408 (0.1 microm, pK(b) = 6.82 +/- 0.34) and RX 821002 (0.1 microm, pKb = 8.31 +/- 0.35), alpha2C-adrenoceptor antagonists spiroxatrine (1 microm, pKb = 7.32 +/- 0.32), rauwolscine (0.1 microm, pKb = 8.16 +/- 0.14) and HV 723 (0.3 microm, pKb = 7.68 +/- 0.14) inhibited BHT-920-induced contractions in pig nasal mucosa. 4. The present antagonist potencies showed correlations with binding affinity estimates (pKi) obtained for these antagonists at the human recombinant alpha2A- and alpha2C-adrenoceptors (r = 0.78 and 0.83, respectively) and with binding affinity estimates (pKd) obtained in pig native alpha2A- and alpha2C-monoreceptor assays (r = 0.85 and 0.78, respectively). No correlation was observed for the alpha2B-subtype. 5. In conclusion, contractile responses to phenylephrine, BHT-920, UK 14,304, PGE-6201204 and oxymetazoline indicate that alpha1- and alpha2-adrenoceptors are present and mediate vasoconstriction in pig nasal mucosa. Furthermore, correlation analysis comparing antagonist potency in pig nasal mucosa with affinities for human recombinant alpha2-adrenoceptors and native pig alpha2-adrenoceptors suggest that alpha2A- and alpha2C-adrenoceptor subtypes constrict pig nasal mucosa vasculature.
Assuntos
Antagonistas de Receptores Adrenérgicos alfa 2 , Antagonistas Adrenérgicos alfa/metabolismo , Mucosa Nasal/metabolismo , Receptores Adrenérgicos alfa 2/metabolismo , Antagonistas Adrenérgicos alfa/farmacologia , Animais , Células CHO , Cricetinae , Relação Dose-Resposta a Droga , Feminino , Humanos , Técnicas In Vitro , Masculino , Mucosa Nasal/efeitos dos fármacos , Ligação Proteica/efeitos dos fármacos , Ligação Proteica/fisiologia , SuínosRESUMO
Costs of biologic response modifiers, specifically myeloid growth factors, are discussed relative to cost offsets they may produce in the total amount spent on health care in patients with certain disease states. Even though the biologic response modifiers granulocyte colony-stimulating factor (filgrastim) and granulocyte-macrophage colony-stimulating factor (sargramostim or molgramostim) are similar in name, they are chemically and biologically different. These differences result in different clinical applications. Administered after myelosuppressive antineoplastic therapy, filgrastim decreases the risk of infection. The growth factors may also be useful in patients undergoing bone marrow transplantation, in nonneutropenic patients with bacterial infections, and in patients with other disease states. Although the myeloid growth factors are somewhat expensive in terms of acquisition cost, their use is usually associated with a decrease in the risk of medical complications requiring health care expenditures, often for hospitalizations or antimicrobials. The precise cost of acquiring and administering myeloid growth factors depends on three interdependent variables: the factor used, the dosage of the drug, and the duration of therapy. Cost offsets may be more difficult to define, but they would include direct cost offsets, such as reduced episodes of febrile neutropenia and fewer, less-intense days of hospitalization or treatment. Sargramostim and molgramostim have demonstrated efficacy when given after bone marrow transplantation; filgrastim has been shown to lower infection rates by at least 50% after myelosuppressive antineoplastic therapy and in patients with severe chronic neutropenia.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Fatores Estimuladores de Colônias/uso terapêutico , Fator Estimulador de Colônias de Granulócitos e Macrófagos , Síndrome da Imunodeficiência Adquirida/terapia , Antineoplásicos/economia , Antineoplásicos/uso terapêutico , Transplante de Medula Óssea , Fatores Estimuladores de Colônias/economia , Custos e Análise de Custo , Filgrastim , Fator Estimulador de Colônias de Granulócitos/economia , Fator Estimulador de Colônias de Granulócitos/uso terapêutico , Fator Estimulador de Colônias de Granulócitos e Macrófagos/economia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/uso terapêutico , Humanos , Síndromes Mielodisplásicas/economia , Síndromes Mielodisplásicas/terapia , Neutropenia/economia , Neutropenia/terapia , Proteínas Recombinantes/economia , Proteínas Recombinantes/uso terapêuticoRESUMO
The nature of the defect(s) in the ability of UV-treated guinea pig macrophages to stimulate the proliferative response of guinea pig T cells to soluble protein antigens was investigated. T cells proliferated vigorously when cultured with peritoneal exudate cells (PEC) which had been pulsed with soluble protein antigens, but failed to proliferate when cultured with soluble antigen or with antigen-pulsed, UV-treated PEC. UV-treated macrophages were unable to secrete interleukin 1 (IL-1). Addition of IL-1 partially restored the T-cell proliferative response stimulated by antigen-pulsed, UV-treated PEC. However, IL-1 was able to restore such a response only when the PEC were pulsed with antigen before being exposed to UV. Similar results were obtained when antigen-pulsed PEC were used to stimulate T cells to secrete interleukin 2 (IL-2). These results demonstrate that UV-treated macrophages are defective both in their ability to properly process and present antigen for T-cell recognition and in their ability to secrete IL-1.
Assuntos
Interleucina-1/biossíntese , Ativação Linfocitária , Macrófagos/imunologia , Linfócitos T/metabolismo , Animais , Cobaias , Interleucina-2/biossíntese , Ativação Linfocitária/efeitos da radiação , Macrófagos/efeitos da radiação , Ovalbumina/imunologia , Tuberculina/imunologia , Raios UltravioletaRESUMO
In this report we investigated the ability of macrophage-associated OVA to stimulate purified OVA-immune T-lymphocytes to produce nonspecific helper activity for antibody production. T-cell activation required only a brief contact between the antigen-pulsed macrophages and T-lymphocytes and was maximal after a 4-hr contact. T-cell activation occurred at 37 but not at 4 degrees C, indicating that the macrophages and/or lymphocytes must be metabolically active for efficient activation. In addition, we compared the ability of antigen-pulsed syngeneic or allogeneic macrophages to activate T-cells for helper function.
Assuntos
Formação de Anticorpos , Antígenos , Macrófagos/imunologia , Linfócitos T/imunologia , Animais , Antígenos de Histocompatibilidade , Masculino , Camundongos , Camundongos Endogâmicos , Ovalbumina/imunologia , Baço/imunologia , TemperaturaRESUMO
Cross-linking of membrane immunoglobulin, the B cell receptor for antigen, activates the phosphoinositide signal transduction pathway. The initial event in this pathway is the hydrolysis of phosphatidylinositol 4,5-bisphosphate (PtdInsP2) by phospholipase C. This reaction yields two intracellular second messengers, diacylglycerol, which activates protein kinase C, and inositol trisphosphate, which causes an increase in cytoplasmic Ca2+. The experiments reported here demonstrate that activation of phospholipase C by membrane IgM (mIgM) involves a guanine nucleotide-dependent step. Saponin was used to permeabilize WEHI-231 B lymphoma cells and permit direct manipulation of nucleotide and Ca2+ concentrations. Very high levels of Ca2+ (greater than 100 microM) activated the phospholipase maximally without a requirement for cross-linking of mIgM. However, at much lower, physiologically relevant Ca2+ concentrations (100 to 500 nM), receptor-stimulated PtdInsP2 hydrolysis could be demonstrated. The ability of anti-IgM antibodies to activate phospholipase C in permeabilized WEHI-231 cells was greatly increased by nonhydrolyzable guanosine 5'-triphosphate (GTP) analogues (guanosine-5'-O-(3-thiotriphosphate) or 5'-guanylylimidodiphosphate), but not by guanosine diphosphate or guanosine diphosphate analogues or by a nonhydrolyzable analogue of adenosine triphosphate. This specificity for GTP analogues is consistent with the hypothesis that a GTP-binding regulatory protein analogous to those that couple receptors to adenylate cyclase is involved in the activation of phospholipase C by mIgM in WEHI-231 B lymphoma cells. In order to characterize this putative GTP-binding component, we examined the ability of pertussis toxin and cholera toxin to affect anti-IgM-stimulated inositol phosphate production. These bacterial toxins covalently modify and modulate the activity of various GTP-binding regulatory proteins and in some cell types can block receptor-stimulated PtdInsP2 breakdown. In WEHI-231 B lymphoma cells, neither toxin blocked signaling by mIgM. Thus mIgM appears to be coupled to the phosphoinositide signaling pathway by a GTP-dependent component that is insensitive to both pertussis toxin and cholera toxin.
Assuntos
Linfócitos B/fisiologia , Proteínas de Ligação ao GTP/fisiologia , Imunoglobulina M/imunologia , Fosfatidilinositóis/metabolismo , Receptores de Antígenos de Linfócitos B/imunologia , Toxina Adenilato Ciclase , Animais , Linfócitos B/efeitos dos fármacos , Linfócitos B/imunologia , Cálcio/metabolismo , Linhagem Celular , Toxina da Cólera/farmacologia , Guanosina 5'-O-(3-Tiotrifosfato) , Guanosina Trifosfato/análogos & derivados , Guanosina Trifosfato/metabolismo , Camundongos , Toxina Pertussis , Tionucleotídeos/metabolismo , Células Tumorais Cultivadas/efeitos dos fármacos , Células Tumorais Cultivadas/imunologia , Células Tumorais Cultivadas/fisiologia , Fatores de Virulência de Bordetella/farmacologiaRESUMO
A modification of the microchromatographic procedure for Hb-A2 which utilizes DEAE-cellulose (Reference 1) allows the quantitation of Hb-A2 without interference from any Hb-S in the sample. Elution of Hb-A2 with a glycine-KCN developer is much less sensitive to minor change in pH of the developer, but is greatly dependent on the pH of the ion exchanger.
Assuntos
Cromatografia DEAE-Celulose/métodos , Hemoglobinometria/métodos , Hemoglobinas Anormais/análise , HumanosRESUMO
Mometasone furoate (9 alpha, 21 dichloro-11 beta, 17 alpha dihydroxy-16 alpha methyl-1,4 pregnadiene-3, 20 dione-17-[2'] furoate) was an unexpectedly potent inhibitor of the in vitro production of three inflammatory cytokines, IL-1(1), IL-6, and TNF-alpha. The potency of mometasone furoate in inhibiting cytokine production was compared to that of hydrocortisone, betamethasone, dexamethasone, and beclomethasone. IL-6 and TNF-alpha were both produced by WEHI-265.1 (murine myelomonocytic leukemia) cells following stimulation by lipopolysaccharide (LPS). Twenty-four hours after stimulation by LPS, the cell-free supernatant fluids were removed. Their cytokine content was analyzed using ELISAs specific for each cytokine. IL-1 synthesis was induced in the harvested peritoneal macrophages of BALB/c mice by incubation with LPS for twenty-four hours. The IL-1 content in the cell-free supernatant fluids was determined by the thymocyte-costimulator bioassay. Using these systems, mometasone furoate was found to be the most potent steroid tested for inhibiting the production of the three cytokines. The IC50's were 0.05 nM (IL-1), 0.15 nM (IL-6), and 0.25 nM (TNF-alpha). The inhibition of the production of proinflammatory mediators by extremely low concentrations of mometasone furoate suggests that this steroid should be highly effective in various disorders.
Assuntos
Anti-Inflamatórios/farmacologia , Interleucina-1/antagonistas & inibidores , Interleucina-6/antagonistas & inibidores , Pregnadienodiois/farmacologia , Fator de Necrose Tumoral alfa/antagonistas & inibidores , Administração Tópica , Animais , Glucocorticoides , Interleucina-1/biossíntese , Interleucina-6/biossíntese , Camundongos , Furoato de Mometasona , Células Tumorais Cultivadas , Fator de Necrose Tumoral alfa/biossínteseRESUMO
We assessed the dependency of a variety of immune responses for IL 2 in vitro by using anti-IL 2 receptor monoclonal antibodies as specific inhibitors of IL 2 function. The generation of allogeneic cytotoxic T lymphocyte (CTL) responses and maximal thymocyte proliferation to phytohemagglutinin (PHA) and IL 1 was readily susceptible to inhibition by these antibodies. Furthermore, the IL 2 receptor-positive, IL 2-responsive cell in the CTL cultures expressed killer cell activity. A greater variability in susceptibility to anti-IL 2 receptor antibody inhibition was noted for proliferation of T cells to concanavalin A, PHA, or allogeneic cells. Under certain conditions, however, each of these responses was almost completely inhibited. In most instances, the failure to block a response could be accounted for by either high levels of endogenous IL 2 production or high density of cell surface IL 2 receptors, which represent two known variables that influence the level of inhibition by these antibodies. Analysis of IL 2 receptor expression by mitogen-stimulated T cells suggested that accessory cells may play a role in the optimal expression of the IL 2 receptor. These experiments demonstrate that IL 2 is the predominant growth factor by which T lymphocytes proliferate, but do not exclude the possibility of an IL 2-independent pathway for growth.
Assuntos
Anticorpos Monoclonais/fisiologia , Especificidade de Anticorpos , Tolerância Imunológica , Receptores Imunológicos/imunologia , Linfócitos T/imunologia , Animais , Interleucina-2/metabolismo , Interleucina-2/fisiologia , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Mitógenos/farmacologia , Receptores de Interleucina-2 , Linfócitos T Citotóxicos/imunologia , Linfócitos T Citotóxicos/metabolismoRESUMO
A new system for typing and screening blood, based on the sieving effect of glass bead microparticles, has been developed. The test is performed in a microcolumn in which the red cell agglutinates are trapped in the glass bead matrix during centrifugation, and unagglutinated cells form a pellet at the bottom of the column. Anti-human globulin reagents were incorporated in the diluent and the new test system, column agglutination technology, was compared to conventional tube tests and low-ionic-strength method. Sera and plasmas (228 samples) were screened for red cell antibodies with two anti-human globulin reagents: one containing only anti-IgG and the other containing both anti-IgG and anti-C3b, -C3d. After initial testing, there was 94-percent agreement between column agglutination technology and tube tests, and after repeat testing, there was 97-percent agreement. The column agglutination technology anti-human globulin test eliminates the need to wash red cells, which decreases the overall test time. The test is easy to perform, and the results are more objective than those with tube and microplate methods.
Assuntos
Testes de Hemaglutinação/métodos , Anticorpos Anti-Idiotípicos , Tipagem e Reações Cruzadas Sanguíneas , Teste de Coombs/métodos , Testes de Hemaglutinação/instrumentação , Humanos , Imunoglobulina G/sangue , Testes de NeutralizaçãoRESUMO
The growth of WEHI-231, a murine immature B lymphoma cell line, was inhibited by anti-IgM antibodies. The inhibition of proliferation, as measured by [3H]thymidine incorporation, occurred between 16 and 28 hr after addition of anti-IgM. Moreover, the growth arrest was irreversible: cells that were cultured with anti-IgM for 18 hr and then recultured without it failed to recover the ability to proliferate, even though cells treated for up to 30 hr with anti-IgM remained viable, as measured by trypan blue exclusion. Three polyclonal B cell activators obtained from bacteria, lipopolysaccharide (LPS), peptidoglycan from Staphylococcus aureus, and gliding bacterial adjuvant from Cytophaga (GBA), were able to protect WEHI-231 cells from anti-IgM-induced growth arrest. The protection was transient, ending after approximately 56 hr. This transience was shown to be due to desensitization of the cells to the bacterial products. Interestingly, pretreatment of WEHI-231 cells with any of the bacterial products desensitized the cells to all of the bacterial products. The heterologous nature of this desensitization suggests that all three of these bacterial products may act through a common signaling pathway despite their diverse chemical natures.
Assuntos
Linfócitos B/patologia , Linfoma/patologia , Adjuvantes Imunológicos/imunologia , Animais , Anticorpos Anti-Idiotípicos/imunologia , Ciclo Celular , Diferenciação Celular , Linhagem Celular , Tolerância Imunológica , Imunoglobulina M/imunologia , Lipopolissacarídeos/farmacologia , Ativação Linfocitária/efeitos dos fármacos , Camundongos , Peptidoglicano/farmacologia , Polimixina B/farmacologia , Polissacarídeos Bacterianos/imunologia , Receptores de Antígenos de Linfócitos B/imunologiaRESUMO
We compared the effects of cyclosporin A (CSA) and a macrotetrolide antibiotic, dinactin, on human T-cell proliferation and cytokine production induced by stimulation of the T-cell receptor alone (monoclonal antibody [mAb] directed against CD3) or in combination with costimulatory signals (mAbs directed against CD3 and CD28). These agents were also examined in a murine model of interleukin (IL)-5-mediated pulmonary inflammation. Dinactin inhibited T-cell proliferation induced by IL-2, by mAb to CD3, and by mAbs to CD3 plus alpha-CD28 with identical dose-response curves (IC50 = 10-20 ng/ml). Dinactin inhibited cytokine production with IC50 values of 10 ng/ml for IL-4 and IL-5 and 30 or 60 ng/ml for interferon-gamma or IL-2, respectively. Unlike CSA, exogenous IL-2 did not alter the dinactin-mediated effects on T cells, and nuclear run-on and steady-state messenger RNA (mRNA) analysis showed that dinactin inhibited cytokine production through a post-transcriptional mechanism. CSA selectively blocked T-cell receptor-induced T-cell proliferation and cytokine production (IC50 = 10 ng/ml). Under costimulatory conditions, IL-5 synthesis was only minimally inhibited by high concentrations of CSA, and at CSA concentrations of less than 125 ng/ml, IL-5 was significantly increased above control values. Dinactin and CSA reduced pulmonary eosinophilia when administered within 1 d of airway antigen challenge. Of the cytokine mRNAs examined in the lungs of CSA-pretreated, antigen-challenged mice, IL-5 mRNA levels were the least reduced, paralleling the resistance of IL-5 to CSA observed in vitro and suggesting a role for CD28 in the in vivo induction of IL-5.