RESUMEN
IL-10 has been previously called cytokine synthesis inhibiting factor, produced mostly by Th2 cells, macrophages and CD8+ cell clones. IL-10 is capable of inhibiting the synthesis of several cytokines from different cells, antigen or mitogen activated. IL-10 exerts its inhibition at the mRNA transcriptional and translational level. In addition, IL-10 is a co-stimulatory cytokine on activated T cells. For example, IL-10 inhibits NK cell activity, the production of Th1 cytokines, cytokines generated by peripheral blood mononuclear cells, and macrophage activity. On the other hand, IL-10 exerts immunostimulatory effects on B cells, cytotoxic T cell development and thymocytes. In mast cells derived from CD4+/CD133+ cells, IL-10 inhibits IL-6 and TNFalpha, and prostaglandin E(1) and E(2) induced by IL-6. Here, we report for the first time that IL-10 fails to inhibit tryptase and IL-6 from human mast cell-1 (HMC-1) and human umbilical cord blood-derived mast cells.
Asunto(s)
Interleucina-10/fisiología , Humanos , Inflamación/inmunología , Mastocitos/inmunología , Mastocitos/ultraestructura , Modelos InmunológicosRESUMEN
Interleukin (IL) 6 is a pleiotropic cytokine (26 kDa) that originally was named interferon beta 2 or B cell-stimulating factor or differentiating B cell factor inducing immunoglobulin production. IL-6 is produced in many diseases. After secretion, IL-6 binds to its receptor IL-6R alpha (gp 80), the IL-6R alpha complex then recruits the signal-transducing beta-subunit (gp 130), which is the functional complex for signal transduction. In addition, activation of Th2 cells or mast cells also produce IL-6, which mediates immune responses, inflammation, acute phase responses, hematopoiesis, cancer, inflammatory bowel disease, etc. IL-6 also is a crucial cytokine for mast cell maturation. Human cord blood CD34+ cells differentiate and grow into mast cells in the presence of stem cell factor (SCF) and IL-6, causing increases in cell size, frequency of chymase positive cells, and intracellular histamine levels when compared with cells treated with SCF alone. Activated mast cells increase IL-6 mRNA associated with protein kinase C (PKC) activity. IL-6 also up-regulates histamine production rather than increases its storage and is an important inducing factor for the expression of immunoglobulin E (IgE) Fc epsilon RI.
Asunto(s)
Inflamación/fisiopatología , Interleucina-6/fisiología , Mastocitos/fisiología , HumanosRESUMEN
Stress activates the hypothalamic-pituitary-adrenal axis through release of corticotropin releasing hormone (CRH), leading to production of glucocorticoids that down-regulate immune responses. Acute stress, however, also has proinflammatory effects that seem to be mediated through the activation of mast cells. Stress and mast cells have been implicated in the pathophysiology of various inflammatory conditions, including some in the central nervous system, such as multiple sclerosis in which disruption of the blood-brain barrier (BBB) precedes clinical symptoms. We previously showed that acute restraint stress increases rat BBB permeability to intravenous 99Tc gluceptate and that administration of the "mast cell stabilizer" disodium cromoglycate (cromolyn) inhibits this effect. In this study, we show that the CRH-receptor antagonist Antalarmin blocks stress-induced 99Tc extravasation, whereas site-specific injection of CRH in the paraventricular nucleus (PVN) of the hypothalamus mimics acute stress. This latter effect is blocked by pretreatment of the PVN with cromolyn; moreover, restraint stress cannot disrupt the BBB in the diencephalon and cerebellum of W/W(v) mast cell-deficient mice. These results demonstrate that CRH and mast cells are involved in regulating BBB permeability and, possibly, brain inflammatory disorders exacerbated by acute stress.
Asunto(s)
Barrera Hematoencefálica/fisiología , Encéfalo/fisiología , Hormona Liberadora de Corticotropina/fisiología , Mastocitos/fisiología , Estrés Fisiológico/fisiopatología , Animales , Barrera Hematoencefálica/efectos de los fármacos , Hormona Liberadora de Corticotropina/farmacología , Masculino , Mastocitos/efectos de los fármacos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Permeabilidad/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Receptores de Hormona Liberadora de Corticotropina/antagonistas & inhibidores , Receptores de Hormona Liberadora de Corticotropina/fisiología , Restricción FísicaRESUMEN
Interleukin (IL)-16 is a homotetramer of 14-kDa subunits discovered in 1982 as a T-cell-specific chemoattractant factor. IL-16 plays a role in trafficking of several immune cells and may be a major chemotactic signal for CD4+ cells. Here, we review some of the key biological actions of IL-16. Because this cytokine has been shown to affect the levels of many inflammatory mediators such as histamine, serotonin, regulated upon activation, normal T cell expressed and secreted (RANTES), and monocyte chemotactic protein-1 (MCP-1), and other cytokines such as IL-2, we investigated the effect of IL-16 on control and stimulated human umbilical cord blood-derived cultured mast cells after antigen challenge. We found that human recombinant IL-16 (0.2-200 ng/mL) does not affect either basal tryptase or IL-8 release or that induced by anti-immunoglobulin E activation. In accordance with other data in the medical literature, we conclude that the most important function of IL-16 is the chemoattraction of CD4+ cells.
Asunto(s)
Hipersensibilidad/inmunología , Inflamación/inmunología , Interleucina-16/inmunología , Antígenos CD4/inmunología , Humanos , Linfocitos T/inmunologíaRESUMEN
BACKGROUND: Mast cells are involved in early- and late-phase reactions by releasing vasoactive molecules, proteases, and cytokines. Certain histamine-1 receptor antagonists and other antiallergic drugs seem to inhibit the release of mediators from rat and human mast cells. OBJECTIVE: Azelastine and olopatadine are antiallergic agents present in the ophthalmic solutions azelastine hydrochloride (Optivar, Asta Medica/Muro Pharmaceuticals, Tewksbury, MA), and olopatadine hydrochloride (Patanol, Alcon Laboratories, Fort Worth, TX), respectively. We investigated the effect of these drugs on interleukin-6 (IL-6), tryptase, and histamine release from cultured human mast cells (CHMCs). METHODS: CHMCs were grown from human umbilical cord blood-derived CD34+ cells in the presence of stem cell factor and IL-6 for 14 to 16 weeks. Sensitized CHMCs were pretreated with various concentrations of azelastine or olopatadine for 5 minutes. CHMCs were then challenged with anti-immunoglobulin E, and the released mediators were quantitated. RESULTS: The greatest inhibition of mediator release was seen with 24 microM azelastine; this level of inhibition was matched with the use of 133 microM olopatadine. At this concentration, these drugs inhibited IL-6 release by 83% and 74%, tryptase release by 55% and 79%, and histamine release by 41% and 45%, respectively. Activated CHMCs were characterized by numerous filopodia that were inhibited by both drugs as shown by electron microscopy. CONCLUSIONS: These results indicate that azelastine and olopatadine can inhibit CHMCs activation and release of IL-6, tryptase, and histamine. On an equimolar basis, azelastine was a more potent inhibitor than olopatadine.
Asunto(s)
Antialérgicos/farmacología , Dibenzoxepinas/farmacología , Interleucina-6/metabolismo , Mastocitos/efectos de los fármacos , Ftalazinas/farmacología , Serina Endopeptidasas/metabolismo , Células Cultivadas , Relación Dosis-Respuesta a Droga , Sangre Fetal , Liberación de Histamina/efectos de los fármacos , Humanos , Activación de Linfocitos , Mastocitos/metabolismo , Clorhidrato de Olopatadina , TriptasasRESUMEN
Mast cells are involved in early and late-phase reactions by releasing vasoactive molecules, proteases, and cytokines. Azelastine and olopatadine are histamine 1 receptor (H-1R) antagonists with antiallergic effects present in the ophthalmic solutions Optivar and Patanol, respectively. Because it is difficult to obtain animal or human conjunctival tissue, we first investigated the effect of these compounds on histamine and tryptase release from cultured human mast cells (CHMCs) grown out of human umbilical cord blood-derived CD34+ cells. Sensitized CHMCs were pretreated with various concentrations of azelastine or olopatadine for 5 minutes. Then, CHMCs were challenged with anti-immunoglobulin E (IgE) and the released mediators were quantitated. The greatest inhibition of mediator release was seen when CHMCs were pretreated with 24 microM of azelastine or 133 microM of olopatadine (2% dilution of azelastine or 5% olopatadine original ophthalmic solutions, respectively). We then studied the drug concentrations that gave optimal results on skin vasodilation induced by the mast cell secretagogue compound 48/80. An intradermal injection of 48/80 in rats, to which Evan's blue had been administered via the tail vein, induced substantial dye extravasation. Pretreatment of the injection site for 5 minutes with either 24 microM of azelastine or 133 microM of olopatadine completely prevented extravasation; this effect was quantitated also by fluorometric assessment of Evan's blue extracted in formamide. Evaluation of skin mast cells from injected sites showed that mast cell degranulation was inhibited greatly. These results indicate that on an equimolar basis, azelastine was a more potent inhibitor than olopatadine of both CHMC and rat skin mast cells activation.