RESUMO
Activation of the high affinity IgE receptor (Fc epsilonRI) through IgE-antigen complexes induces mast cell degranulation, synthesis of lipid mediators and cytokine production. These effects are involved in Type I hypersensitivity reactions and controlling them has been the main objective of many anti-allergic therapies. Here we report that pretreatment of murine bone marrow derived mast cells (BMMC) with super-oxidized solution (SOS) inhibits Fc epsilonRI dependent-beta hexosaminidase and cytokine release. This effect is exerted without altering total protein tyrosine phosphorylation, MAPK activation, cytokine mRNA accumulation or calcium mobilization after Fc epsilonRI triggering. Our data suggest that this neutral pH-SOS acts like a mast cell-membrane stabilizer inhibiting the cell machinery for granule secretion without altering the signal transduction pathways induced by IgE-antigen receptor crosslinking.
Assuntos
Degranulação Celular/efeitos dos fármacos , Citocinas/metabolismo , Peróxido de Hidrogênio/toxicidade , Imunoglobulina E/imunologia , Mastócitos/efeitos dos fármacos , Animais , Western Blotting , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Células da Medula Óssea/metabolismo , Cálcio/metabolismo , Degranulação Celular/imunologia , Sobrevivência Celular/efeitos dos fármacos , Citocinas/genética , Desinfetantes/toxicidade , Ensaio de Imunoadsorção Enzimática/métodos , Mastócitos/metabolismo , Mastócitos/fisiologia , Camundongos , Camundongos Endogâmicos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Fatores de Transcrição NFATC/metabolismo , Fosforilação/efeitos dos fármacos , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de IgE/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Hipoclorito de Sódio/toxicidade , Tirosina/metabolismo , beta-N-Acetil-Hexosaminidases/metabolismoRESUMO
The effect of L-glutamate and its structural analog kainate on the binding of [3H]phorbol 12,13-dibutyrate was examined in cultured chick cerebellar Bergmann glia cells. Both glutamate and kainate evoke a dose-dependent increase in the maximal number of binding sites for [3H]phorbol 12,13-dibutyrate in intact cells reflecting an activation and translocation of the Ca2+/diacylglycerol-dependent protein kinase (protein kinase C, PKC) from cytosol to the plasma membrane. Glutamate and kainate responses were blocked by 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) indicating that the increase in [3H]phorbol 12,13-dibutyrate binding sites is mediated by an alpha-amino-3-hydroxy-5-methylisoxazole-4-propionic acid (AMPA)/kainate receptor. Since Bergmann glia AMPA/kainate receptors are probably mediators of the efficacy of the parallel fiber-Purkinje cell synapse, the present findings suggest that the Ca2+/PKC signalling cascade might play a role in such modulation.
Assuntos
Glutamatos/fisiologia , Ácido Ibotênico/análogos & derivados , Neuroglia/metabolismo , Dibutirato de 12,13-Forbol/metabolismo , Proteína Quinase C/metabolismo , Animais , Sítios de Ligação , Membrana Celular/metabolismo , Células Cultivadas , Cerebelo/citologia , Embrião de Galinha , Citosol/enzimologia , Ativação Enzimática , Ácido Glutâmico , Ácido Ibotênico/metabolismo , Ácido Caínico/farmacologia , Células de Purkinje/metabolismo , Ácido alfa-Amino-3-hidroxi-5-metil-4-isoxazol PropiônicoRESUMO
The specificity of sera from patients with amoebiasis was assayed on trophozoites of E. histolytica HK9, HM15 and HM2 cultured axenically and monoxenically. Glutaraldehyde fixed cell were incubated with samples of serum, the excess of Igs was washed out and the presence of unbound material of specifically bound antibodies was measured with radiolabeled protein A from Staphylococcus aureus. A positive reaction with HK9 was observed in 18 per cent of the 66 sera tested. An immune crossreaction resulted with HM2 and HM15, while no reaction was observed with the nonpathogenic strains E. invadens, E. moshkovskii and E. laredo.