RESUMO
The voltage-gated potassium channel Kv1.3 is a novel target for immunomodulation of autoreactive effector memory T cells, which play a major role in the pathogenesis of autoimmune diseases. In this study, the Ts6 and Ts15 toxins isolated from Tityus serrulatus (Ts) were investigated for their immunosuppressant roles on CD4(+) cell subsets: naive, effector (TEF ), central memory (TCM) and effector memory (TEM). The electrophysiological assays confirmed that both toxins were able to block Kv1.3 channels. Interestingly, an extended Kv channel screening shows that Ts15 blocks Kv2.1 channels. Ts6 and Ts15 significantly inhibit the proliferation of TEM cells and interferon-γ production; however, Ts15 also inhibits other CD4(+) cell subsets (naive, TEF and TCM). Based on the Ts15 inhibitory effect of proliferation of all CD4(+) cell subsets, and based on its blocking effect on Kv2.1, we investigated the Kv2.1 expression in T cells. The assays showed that CD4(+) and CD8(+) cells express the Kv2.1 channels mainly extracellularly with TCM cells expressing the highest number of Kv2.1 channels. We also provide in vivo experimental evidence to the protective effect of Ts6 and Ts15 on delayed-type hypersensitivity reaction. Altogether, this study presents the immunosuppressive behaviour of Ts6 and Ts15 toxins, indicating that these toxins could be promising candidates for autoimmune disease therapy. Moreover, this is the first report illustrating the involvement of a novel K(+) channel subtype, Kv2.1, and its distribution in T-cell subsets.
Assuntos
Imunossupressores/farmacologia , Bloqueadores dos Canais de Potássio/farmacologia , Canais de Potássio de Abertura Dependente da Tensão da Membrana/antagonistas & inibidores , Venenos de Escorpião/farmacologia , Linfócitos T/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Feminino , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Tardia/metabolismo , Hipersensibilidade Tardia/prevenção & controle , Canal de Potássio Kv1.3/antagonistas & inibidores , Canal de Potássio Kv1.3/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Masculino , Potenciais da Membrana , Camundongos Endogâmicos BALB C , Canais de Potássio de Abertura Dependente da Tensão da Membrana/genética , Canais de Potássio de Abertura Dependente da Tensão da Membrana/metabolismo , Soroalbumina Bovina , Canais de Potássio Shab/antagonistas & inibidores , Canais de Potássio Shab/metabolismo , Linfócitos T/imunologia , Linfócitos T/metabolismo , Xenopus laevisRESUMO
Delayed, or type IV, hypersensitivity reactions are a useful model to study the effects of new substances on the immune system. In this study, the experimental model of the delayed type hypersensitivity (DTH) reaction to ovalbumin (OVA) was used to evaluate the immunomodulating effects of low-level laser therapy (LLLT), which is used as an adjuvant therapy in medicine, dentistry, and physical therapy because of its potential anti-inflammatory and analgesic effects observed in several studies. The effects of LLLT (λ 780 nm, 0.06 W/cm(2) of radiation, and fluency of 3.8 J/cm(2)) in reaction to ovalbumin in Balb/C mice were examined after the induction phase of the hypersensitivity reaction. The animals treated with azathioprine (AZA), the animals that received a vehicle instead of ovalbumin, and those not immunized served as controls (n = 6 for each group). Footpad thickness measurements and hematoxylin-eosin histopathological exams were performed. Proliferation tests were also performed (spontaneous, in the presence of concanavalin A and ovalbumin) to determine the production in mononuclear cells cultures of tumor necrosis factor-alpha (TNF-α), INF-γ, and IL-10. In the group of animals irradiated with lasers and in the group treated with AZA, footpad thickness measurements were significantly reduced in comparison to the control group (p < 0.05). This reduction was accompanied by a very significant reduction in the density of the inflammatory infiltrate and by a significant reduction in the levels of TNF-α, INF-γ, and IL-10. LLLT radiation was shown to have an immunomodulating effect on DTH to OVA in Balb/C mice.
Assuntos
Hipersensibilidade Tardia/prevenção & controle , Interferon gama/biossíntese , Interleucina-10/biossíntese , Terapia com Luz de Baixa Intensidade , Fator de Necrose Tumoral alfa/biossíntese , Animais , Azatioprina/farmacologia , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Tardia/patologia , Terapia de Imunossupressão/métodos , Imunossupressores/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/imunologiaRESUMO
Oral tolerance promotes a generalized decrease in specific immune responsiveness to proteins previously encountered via the oral route. In addition, parenteral immunization with a tolerated protein also triggers a significant reduction in the primary responsiveness to a second unrelated antigen. This is generally explained by 'innocent bystander suppression', suggesting that the transient and episodic effects of inhibitory cytokines released by contact with the tolerated antigen would block responses to the second antigen. In disagreement with this view, we have previously shown that: (i) these inhibitory effects do not require concomitance or contiguity of the injections of the two proteins; (ii) that intravenous or intragastric exposures to the tolerated antigen are not inhibitory; and (iii) that the inhibitory effect, once triggered, persists in the absence of further contact with the tolerated protein, possibly by inhibition of secondary responsiveness (immunological memory). The present work confirms that immunological memory of the second unrelated antigen is hindered by exposure to the tolerated antigen and, in addition, shows that this exposure: (i) inhibits the inflammation triggered by an unrelated antigen through the double effect of inhibiting production of leucocytes in the bone marrow and blocking their migration to inflammed sites; and (ii) significantly blocks footpaw swelling triggered by carrageenan. Taken together, these results conclusively demonstrate that inhibitory effects of parenteral injection of tolerated antigens are much more general than suggested by the 'innocent bystander suppression' hypothesis.
Assuntos
Hipersensibilidade Tardia/prevenção & controle , Tolerância Imunológica/imunologia , Proteínas/imunologia , Administração Oral , Animais , Antígenos/administração & dosagem , Efeito Espectador , Carragenina/imunologia , Dinitrofenóis/imunologia , Eosinofilia/imunologia , Eosinofilia/prevenção & controle , Feminino , Hipersensibilidade Tardia/imunologia , Imunidade Celular , Imunidade nas Mucosas , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Ovalbumina/imunologia , Peritonite/imunologia , Peritonite/prevenção & controle , Proteínas/administração & dosagemRESUMO
BACKGROUND: 5HT-3 antagonists and corticosteroids control less than 50% of delayed chemotherapy induced nausea and vomiting (CINV) episodes. MATERIALS AND METHODS: Two pilot phase II studies were conducted at our institution in which all patients received ondansetron 16 mg and dexamethasone 20 mg before highly and moderately emetogenic chemotherapy on day 1. Patients on study 1 received metoclopramide 10 mg PO q8 h, granisetron 0.5 mg PO QD and dexamethasone 8 mg QD on days 2 and 3, whereas only metoclopramide was continued on the same schedule on day 4. On study 2, patients received the same medications, but no drugs were given on day 2, and the same treatment schedule was given to them but from days 3 to 5 instead. Patients were interviewed on days 1 and 6. RESULTS: Twenty-one patients participated on each study. There were no significant clinical differences between these two studied populations. Complete CINV control occurred from days 2 to 5 in 23.1% (95% CI: 8 to 47%) on study 1 vs 61.9% (95% CI: 38 to 81%) of the patients on study 2. By logistic regression, complete CINV control was correlated significantly with antiemetic treatment group (p=0.011) even when we considered only patients who achieved complete CINV control during the first 24 h (p=0.031). CONCLUSIONS: Skipping day 2 antiemetic medications does not seem to worsen delayed CINV control and may even improve it, perhaps by avoiding tachyphylaxis to these medications. A randomized controlled study is in progress to confirm these results.
Assuntos
Antieméticos/administração & dosagem , Protocolos de Quimioterapia Combinada Antineoplásica/efeitos adversos , Hipersensibilidade Tardia/induzido quimicamente , Náusea/induzido quimicamente , Náusea/prevenção & controle , Vômito/induzido quimicamente , Vômito/prevenção & controle , Adolescente , Adulto , Idoso , Análise de Variância , Brasil , Dexametasona/administração & dosagem , Hipersensibilidade a Drogas/etiologia , Hipersensibilidade a Drogas/prevenção & controle , Feminino , Granisetron/administração & dosagem , Humanos , Hipersensibilidade Tardia/prevenção & controle , Modelos Logísticos , Masculino , Metoclopramida/administração & dosagem , Pessoa de Meia-Idade , Ondansetron/administração & dosagem , Projetos Piloto , Qualidade de Vida , Projetos de Pesquisa , Antagonistas da Serotonina/administração & dosagem , Resultado do TratamentoRESUMO
GATA-3 appears to be key to the Th2 response. However, few in vivo experiments have examined the function of GATA-3 in Th1 and Th2 immune responses. We developed two lines of GATA-3-transgenic (Tg) mice harboring the SRalpha or lck promoters and examined the Th2 immune responses of mice infected with the intestinal nematode Nippostrongylus brasiliensis and the Th1 responses with purified derivative of tuberculin (PPD) immunization. Numbers of peripheral blood eosinophils in all GATA-3-Tg mice increased 10- to 20-fold after primary infection with N. brasiliensis and 25-100-fold after secondary infection. The number of eosinophils in infected GATA-3-Tg mice was significantly higher than that in infected control littermates. Total IgE levels after primary infection in GATA-3-Tg mice were 8-450-fold increased, which was significantly higher than those of control mice. Mesenteric lymph node cells of infected GATA-3-Tg mice upon stimulation with N. brasiliensis antigen secreted more IL-5 and IL-13 than those of control mice. However, production of IL-4 and IFN-gamma were comparable between GATA-3-Tg and controls. Mice immunized with PPD were intradermally challenged with PPD to induce delayed type hypersensitivity (DTH). The amount of footpad swelling caused by the DTH reaction in GATA-3-Tg mice was significantly smaller than that of control littermates. Inguinal lymph node cells from GATA-3-Tg mice stimulated with PPD in vitro secreted more IL-5, IL-10 and less IFN-gamma than those of control littermates. These results suggested that Th1 and Th2 driven conditions enhance IL-5 production in GATA-3-Tg mice through the direct binding of GATA-3 to the IL-5 promoter region. The influence of GATA-3 on IL-13, IFN-gamma and IL-10 production varied according to the stimulating conditions. However, IL-4 production was not significantly elevated in GATA-3-Tg mice, indicating that IL-4 and IL-5 production was differentially regulated in these mice.
Assuntos
Antígenos de Helmintos/imunologia , Citocinas/biossíntese , Proteínas de Ligação a DNA/imunologia , Nippostrongylus/imunologia , Infecções por Strongylida/imunologia , Células Th1/imunologia , Células Th2/imunologia , Transativadores/imunologia , Animais , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Proteínas de Ligação a DNA/biossíntese , Proteínas de Ligação a DNA/genética , Eosinofilia/etiologia , Fator de Transcrição GATA3 , Regulação da Expressão Gênica/imunologia , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Tardia/prevenção & controle , Imunização , Linfonodos/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Regiões Promotoras Genéticas , Transativadores/biossíntese , Transativadores/genética , Tuberculina/administração & dosagem , Tuberculina/imunologiaRESUMO
PURPOSE: Recruitment of lymphocytes into the retina and to the vitreous during the development of experimental autoimmune uveitis (EAU) is governed by factors such as the state of activation of inflammatory cells and the repertoire of adhesion molecules expressed by the local vascular endothelia. alpha4 Integrins and their receptors play an important role during homing of cells to the inflammatory site. In the present study, the effect of alpha4-integrin inhibitor on the development of EAU was investigated. METHODS: EAU was induced either by immunizing B10.RIII mice with the 161-180 peptide or by adoptive transfer of interphotoreceptor retinoid-binding protein (IRBP)-specific uveitogenic T cells. Animals were treated with an active peptide inhibitor (alpha4-api) or a peptide control at different time points after induction of disease. EAU was evaluated by histology 21 to 49 days after immunization. Antigen-specific cell proliferation was evaluated by thymidine incorporation. Cytokine synthesis in culture supernatants and anti-IRBP-specific serum IgG1 and IgG2a were evaluated by ELISA. Delayed-type hypersensitivity was evaluated by ear challenge 2 days before the termination of the experiment. RESULTS: Treatment with alpha4-api had a significant ameliorating effect on EAU. The anti-IRBP antibody response and cellular proliferation were not affected by the treatment, whereas delayed-type hypersensitivity was significantly diminished. Cytokine synthesis was not changed by treatment, except for a decrease in IL-10 levels. CONCLUSIONS: The results show that small-molecule inhibitors of alpha4-integrins can act therapeutically in EAU, possibly by interfering with cell adhesion events involved in the development of the disease.
Assuntos
Doenças Autoimunes/prevenção & controle , Integrina alfa4beta1/antagonistas & inibidores , Oligopeptídeos/uso terapêutico , Uveíte Posterior/prevenção & controle , Transferência Adotiva , Animais , Doenças Autoimunes/imunologia , Doenças Autoimunes/patologia , Citocinas/sangue , Modelos Animais de Doenças , Ensaio de Imunoadsorção Enzimática , Proteínas do Olho/imunologia , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Tardia/prevenção & controle , Imunoglobulina G/sangue , Ativação Linfocitária , Camundongos , Fragmentos de Peptídeos/imunologia , Proteínas de Ligação ao Retinol/imunologia , Linfócitos T/imunologia , Uveíte Posterior/imunologia , Uveíte Posterior/patologiaRESUMO
Crude polysaccharide extracts were obtained from aqueous extracts of the microalgae Chlorella stigmatophora and Phaeodactylum tricornutum. The crude extracts were fractionated by ion-exchange chromatography on DEAE-cellulose columns. The molecular weights of the polysaccharides in each fraction were estimated by gel filtration on Sephacryl columns. The crude polysaccharide extracts of both microalgae showed anti-inflammatory activity in the carrageenan-induced paw edema test. In assays of effects on the delayed hyper-sensitivity response, and on phagocytic activity assayed in vivo and in vitro, the C. stigmatophora extract showed immunosuppressant effects, while the P. tricornutum extract showed immunostimulatory effects.
Assuntos
Adjuvantes Imunológicos/farmacologia , Anti-Inflamatórios não Esteroides/farmacologia , Clorófitas , Edema/prevenção & controle , Fagocitose/efeitos dos fármacos , Fitoterapia , Extratos Vegetais/farmacologia , Adjuvantes Imunológicos/administração & dosagem , Adjuvantes Imunológicos/uso terapêutico , Animais , Anti-Inflamatórios não Esteroides/administração & dosagem , Anti-Inflamatórios não Esteroides/uso terapêutico , Carragenina , Chlorella , Relação Dose-Resposta a Droga , Edema/induzido quimicamente , Feminino , Hipersensibilidade Tardia/prevenção & controle , Indometacina/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Extratos Vegetais/administração & dosagem , Extratos Vegetais/uso terapêutico , Polissacarídeos/química , Ratos , Ratos Sprague-DawleyRESUMO
Papular urticaria (PU) is among the commonest skin ailments in children. Induced specific desensitization to insect bites is theoretically an effective means of prevention of PU. In this double blind placebo controlled study, an oral vaccine prepared from insect saliva was compared with placebo (stable vaccine solvent). Vaccine and placebo effectiveness were tested by counting active PU lesions, serum eosinophils, and IgE, before and after 4 months of treatment. Statistically significant differences between oral vaccine and placebo were not found in the clinical or the immunological variables tested. We conclude that, although a lack of oral vaccine efficacy was suspected, larger study samples are needed to strengthen our conclusion.
Assuntos
Hipersensibilidade Tardia/prevenção & controle , Mordeduras e Picadas de Insetos/imunologia , Urticária/prevenção & controle , Vacinas/uso terapêutico , Pré-Escolar , Estudos Cross-Over , Método Duplo-Cego , Feminino , Humanos , Hipersensibilidade Tardia/etiologia , Lactente , Masculino , México , Estatísticas não Paramétricas , Urticária/etiologiaRESUMO
BB-94 (batimastat) is a broad- spectrum hydroxamic acid-based zinc metalloproteinase inhibitor that inhibits both the matrix metalloproteinases (MMP) and members of the ADAM family of enzymes such as Tumour Necrosis Factor-alpha Cleaving Enzyme (TACE). These enzymes are involved in the regulation of inflammatory processes in tuberculosis. Balb/c mice infected with M. tuberculosis via the intratracheal route were treated with BB-94 for 1 month, starting on the day of infection. Immunohistochemistry, semiquantitative RT-PCR and ELISA assays for cytokines revealed a deficit in IL-1 and IL-2 expression and a premature bias towards IL-4 expression, accompanied by a delay in granuloma formation and more rapid progression of disease in BB-94-treated animals. This situation corrected itself after the drug was withdrawn at 28 days. In contrast, when BB-94 was administered only after 1 month there were no significant changes apart from the presence of amyloid, and a paradoxically increased expression of IL-1alpha. These results cast light on mechanisms of immunity in tuberculosis and also indicate that in patients treated with similar broad-spectrum MMP inhibitors there may be a risk of inappropriate deviation of some immune responses towards a Type-2 cytokine profile.
Assuntos
Citocinas/efeitos dos fármacos , Inibidores de Metaloproteinases de Matriz , Fenilalanina/análogos & derivados , Inibidores de Proteases/farmacologia , Tiofenos/farmacologia , Tuberculose Pulmonar/imunologia , Animais , Antineoplásicos/farmacologia , Citocinas/metabolismo , Esquema de Medicação , Hipersensibilidade Tardia/imunologia , Hipersensibilidade Tardia/prevenção & controle , Interleucinas/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Fenilalanina/farmacologia , Taxa de Sobrevida , Tuberculose Pulmonar/patologia , Zinco/fisiologiaRESUMO
UNLABELLED: Human insulin allergy-immediate or late type III reaction-is a rare event. We report the case of a 33-year-old female patient with insulin-dependent diabetes mellitus for 25 years who presented, in the last 8 years, mild but generalized urticaria partially controlled with oral antihistamines. There was no improvement after changing from mixed beef-pork to human insulin. In the last 3 years another allergic manifestation began: small, localized, subdermal and painful non-erythematous nodules with central hematomas at injection sites, occurring 6-8 h after the insulin injection and lasting for 48 h. The following maneuvers had no benefit: (1) Human insulin (NPH or Lente) administered with dexametasone or xylocain locally, (2) Short acting human insulin with or without previous boiling, (3) Anti-histamine cetirizine dihydrochloride-10 mg/day. The allergic symptoms disappeared only after treatment with short acting human insulin (up to 100 U/day) associated to prednisone-40 mg/day and cetirizine dihydrochloride for 4 months. However, after stopping prednisone the urticaria reappeared and it was relieved with insulin desensitization. The pain at the site of injections persisted. CONCLUSION: This long-standing IDDM patient presented two types of reactions to human insulin: the immediate type (systemic urticaria), treated with antihistamines and desensitization, and the Arthus' type III reaction (nodules and hematomas occurring 6-8 h after the insulin injection) that required glucocorticoid therapy for more than 4 months.
Assuntos
Diabetes Mellitus Tipo 1/complicações , Hipersensibilidade a Drogas/etiologia , Hipersensibilidade Tardia/etiologia , Hipersensibilidade Imediata/etiologia , Hipoglicemiantes/efeitos adversos , Insulina/efeitos adversos , Adulto , Complemento C3/metabolismo , Complemento C4/metabolismo , Diabetes Mellitus Tipo 1/imunologia , Hipersensibilidade a Drogas/prevenção & controle , Feminino , Humanos , Hipersensibilidade Tardia/prevenção & controle , Hipersensibilidade Imediata/prevenção & controle , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Insulina/imunologiaRESUMO
In the present study, we report that Cy-sensitive, MRAG-adherent spleen mononuclear (SpM) inductor-phase T suppressor (Ts) cells obtained from rats pretreated with low doses of a purified fraction (FI) of rat male accessory gland antigens (RAG) are mainly OX19+ and W3/25+. Furthermore, thymocytes from rats pretreated with FI of RAG restore the suppression of the autoimmune response to RAG autoantigens in irradiated recipients of SpM inductor-phase Ts cells. In contrast, thymocytes from rats pretreated with rat heart saline extract (unrelated antigen) did not recuperate the suppression of the autoimmune response detected by macrophage migration inhibitory factor (MIF) and delayed-type hypersensitivity. The suppressor thymocytes did not directly exert their inhibitory effect because they were not effective to suppress the autoimmune response to RAG autoantigens when irradiated recipients did not receive SpM inductor-phase Ts cells. The effect of these thymocytes was found in PNA--but not in PNA+ thymic cell population. The perithymic injection of Toxoplasma gondii did block their suppressor activity. The present report clearly shows an active participation of thymus in the efferent phase of the suppressor circuit that controls the autoimmune response to MRAG. The implications of these findings are discussed.