RESUMEN
The normal response to inhaled Ag is the absence of Ag-specific IgE and cytokine production to later Ag challenges. Although the mechanism of this aerosol-induced IgE tolerance is not completely understood, it may prevent sensitization to inhaled Ags, which could otherwise lead to allergy and asthma. We examined the consequences of ongoing Th1 and Th2 responses in the lungs of mice during OVA inhalation to mimic conditions that may subvert tolerance and lead to sensitization. We found that concurrent, secondary Th2 lung responses to keyhole limpet hemocyanin or primary responses to Nippostrongylus larvae or Asperigillus fumagatus extract prevented establishment of IgE tolerance to aerosolized OVA. Intranasal rIL-4 given before OVA aerosolization also prevented establishment of tolerance, whereas concurrent Th1 responses to influenza virus or Mycobacterium bovis bacillus Calmette-Guérin had no effect. However, once established, aerosol tolerance to OVA could not be completely broken by OVA rechallenge concurrent with a secondary Th2 response to keyhole limpet hemocyanin or A. fumagatus extract, or by intranasal rIL-4. These data suggest that the immune status of the lung of an individual may profoundly influence the initial response to inhaled Ag, and that aerosol-induced IgE tolerance may not be appropriately established in individuals undergoing concurrent, Th2-mediated responses to Ags or pathogens.
Asunto(s)
Antígenos/administración & dosificación , Antígenos/inmunología , Tolerancia Inmunológica/inmunología , Inmunoglobulina E/biosíntesis , Pulmón/inmunología , Células Th2/inmunología , Administración por Inhalación , Administración Intranasal , Aerosoles , Animales , Epítopos de Linfocito T/inmunología , Hemocianinas/administración & dosificación , Hemocianinas/inmunología , Inmunización Secundaria , Inmunoglobulina E/sangre , Memoria Inmunológica , Inyecciones Intraperitoneales , Interleucina-4/administración & dosificación , Pulmón/metabolismo , Ratones , Ratones Endogámicos BALB C , Ovalbúmina/administración & dosificación , Ovalbúmina/inmunología , Proteínas Recombinantes/administración & dosificación , Proteínas Recombinantes/inmunología , Células TH1/inmunología , Células TH1/microbiología , Células TH1/parasitología , Células TH1/virología , Células Th2/metabolismoRESUMEN
Cytokine networking in the lung in response to inhaled Aspergillus fumigatus was assessed using a murine model of primary pulmonary aspergillosis in immunocompetent Crl:CF-1 mice. Inhalation of virulent A. fumigatus (6 x 10(6) CFU) resulted in the induction of interleukin 18 (IL-18), tumor necrosis factor alpha (TNF-alpha), IL-12, and gamma interferon (IFN-gamma) protein in bronchoalveolar lavage fluid and/or lung tissue. Induction of immunoreactive IL-18 preceded induction of TNF-alpha protein, which preceded induction of immunoreactive IL-12 and IFN-gamma. Real-time reverse transcriptase (RT) PCR analysis of infected lung tissue demonstrated that induction of IL-18 protein also preceded induction of pulmonary TNF-alpha, IL-12, and IFN-gamma mRNAs. Mice were subsequently treated with cytokine-specific neutralizing monoclonal antibodies (MAbs) to the IL-18 receptor (anti-IL-18R MAb), TNF-alpha (anti-TNF-alpha MAb), IL-12 (anti-IL-12 MAb), and/or IFN-gamma (anti-IFN-gamma MAb), and effects on intrapulmonary cytokine activity and growth of A. fumigatus were assessed in infected lung homogenates. Simultaneous neutralization of IL-12 and IL-18 resulted in decreased levels of immunoreactive TNF-alpha, while neutralization of IL-18, TNF-alpha, or IL-12 alone or of IL-18 and IL-12 together resulted in decreased levels of immunoreactive IFN-gamma. Simultaneous neutralization of IL-12 and IL-18 or neutralization of TNF-alpha alone or in combination with IL-12, IL-18, or IFN-gamma also resulted in a significant increase in A. fumigatus CFU in lung tissue. Taken together, these results demonstrate that endogenous IL-18, IL-12, and TNF-alpha, through their modulatory effects on both intrapulmonary cytokine activity and growth of A. fumigatus, play key roles in host defense against primary pulmonary aspergillosis.
Asunto(s)
Aspergilosis/inmunología , Aspergillus fumigatus/inmunología , Citocinas/biosíntesis , Enfermedades Pulmonares Fúngicas/inmunología , Pulmón/inmunología , Adyuvantes Inmunológicos , Animales , Aspergilosis/etiología , Líquido del Lavado Bronquioalveolar/inmunología , Inmunocompetencia , Interferón gamma/análisis , Interleucina-12/análisis , Interleucina-18/análisis , Enfermedades Pulmonares Fúngicas/etiología , Masculino , Ratones , Factor de Necrosis Tumoral alfa/análisisRESUMEN
We have characterized a cytokine produced by Th2 cells, designated as IL-25. Infusion of mice with IL-25 induced IL-4, IL-5, and IL-13 gene expression. The induction of these cytokines resulted in Th2-like responses marked by increased serum IgE, IgG(1), and IgA levels, blood eosinophilia, and pathological changes in the lungs and digestive tract that included eosinophilic infiltrates, increased mucus production, and epithelial cell hyperplasia/hypertrophy. In addition, our studies show that IL-25 induces Th2-type cytokine production by accessory cells that are MHC class II(high), CD11c(dull), and lineage(-). These results suggest that IL-25, derived from Th2 T cells, is capable of amplifying allergic type inflammatory responses by its actions on other cell types.
Asunto(s)
Eosinofilia/inducido químicamente , Enfermedades Gastrointestinales/inducido químicamente , Regulación de la Expresión Génica/efectos de los fármacos , Sustancias de Crecimiento/aislamiento & purificación , Hipergammaglobulinemia/inducido químicamente , Interleucina-13/biosíntesis , Interleucina-4/biosíntesis , Interleucina-5/biosíntesis , Interleucinas , Subgrupos de Linfocitos T/efectos de los fármacos , Células Th2/metabolismo , Secuencia de Aminoácidos , Animales , Linaje de la Célula , Células Cultivadas , Clonación Molecular , Proteínas de Unión al ADN/deficiencia , Proteínas de Unión al ADN/genética , Eosinofilia/inmunología , Eosinofilia/patología , Mucosa Gástrica/patología , Enfermedades Gastrointestinales/inmunología , Enfermedades Gastrointestinales/patología , Sustancias de Crecimiento/metabolismo , Sustancias de Crecimiento/farmacología , Sustancias de Crecimiento/toxicidad , Antígenos de Histocompatibilidad Clase II/análisis , Humanos , Hiperplasia , Hipertrofia , Integrina alfaXbeta2/análisis , Interleucina-13/genética , Interleucina-17 , Interleucina-4/genética , Interleucina-5/genética , Mucosa Intestinal/patología , Pulmón/patología , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones Noqueados , Datos de Secuencia Molecular , Proteínas Nucleares , Eosinofilia Pulmonar/inducido químicamente , Eosinofilia Pulmonar/inmunología , Eosinofilia Pulmonar/patología , ARN Mensajero/biosíntesis , Receptores de Interleucina-4/deficiencia , Receptores de Interleucina-4/genética , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Subgrupos de Linfocitos T/metabolismo , Células Th2/químicaRESUMEN
The in vivo role of endogenous interleukin-18 (IL-18) in modulating gamma interferon (IFN-gamma)-mediated resolution of replicative Legionella pneumophila lung infection was assessed using a murine model of Legionnaires' disease. Intratracheal inoculation of A/J mice with virulent bacteria (10(6) L. pneumophila organisms per mouse) resulted in induction of IL-18 protein in bronchoalveolar lavage fluid (BALF) and intrapulmonary expression of IL-18 mRNA. Real-time quantitative RT-PCR analysis of infected lung tissue demonstrated that induction of IL-18 in BALF preceded induction of IL-12 and IFN-gamma mRNAs in the lung. Blocking intrapulmonary IL-18 activity by administration of a monoclonal antibody (MAb) to the IL-18 receptor (anti-IL-18R MAb) prior to L. pneumophila infection inhibited induction of intrapulmonary IFN-gamma production but did not significantly alter resolution of replicative L. pneumophila lung infection. In contrast, blocking endogenous IL-12 activity by administration of anti-IL-12 MAb) alone or in combination with anti-IL-18R MAb inhibited induction of intrapulmonary IFN-gamma and resulted in enhanced intrapulmonary growth of the bacteria within 5 days postinfection. Taken together, these results demonstrate that IL-18 plays a key role in modulating induction of IFN-gamma in the lung in response to L. pneumophila and that together with IL-12, IL-18 regulates intrapulmonary growth of the bacteria.
Asunto(s)
Interferón gamma/fisiología , Interleucina-18/fisiología , Enfermedad de los Legionarios/inmunología , Animales , Femenino , Interferón gamma/genética , Interleucina-12/genética , Interleucina-18/genética , Pulmón/metabolismo , Pulmón/microbiología , RatonesRESUMEN
CD38 is a membrane-associated ecto-nicotinamide adenine dinucleotide (NAD+) glycohydrolase that is expressed on multiple hematopoietic cells. The extracellular domain of CD38 can mediate the catalysis of NAD+ to cyclic adenosine diphosphoribose (cADPR), a Ca2+-mobilizing second messenger, adenosine diphosphoribose (ADPR), and nicotinamide. In addition to its enzymatic properties, murine CD38 has been shown to act as a B-cell coreceptor capable of modulating signals through the B-cell antigen receptor. To investigate the in vivo physiological function(s) of this novel class of ectoenzyme we generated mice carrying a null mutation in the CD38 gene. CD38-/- mice showed a complete loss of tissue-associated NAD+ glycohydrolase activity, showing that the classical NAD+ glycohydrolases and CD38 are likely identical. Although murine CD38 is expressed on hematopoietic stem cells as well as on committed progenitors, we show that CD38 is not required for hematopoiesis or lymphopoiesis. However, CD38-/- mice did exhibit marked deficiencies in antibody responses to T-cell-dependent protein antigens and augmented antibody responses to at least one T-cell-independent type 2 polysaccharide antigen. These data suggest that CD38 may play an important role in vivo in regulating humoral immune responses.
Asunto(s)
Formación de Anticuerpos/fisiología , Antígenos CD , Antígenos de Diferenciación/fisiología , NAD+ Nucleosidasa/deficiencia , NAD+ Nucleosidasa/fisiología , ADP-Ribosil Ciclasa , ADP-Ribosil Ciclasa 1 , Alelos , Animales , Antígenos/inmunología , Antígenos T-Independientes/inmunología , Trasplante de Médula Ósea , Femenino , Hematopoyesis , Inmunización , Cooperación Linfocítica , Masculino , Glicoproteínas de Membrana , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , NAD+ Nucleosidasa/genética , Polisacáridos/inmunología , Quimera por RadiaciónRESUMEN
IL-13 is a potent down-modulator of macrophage proinflammatory activity in vitro, similar in this context to the anti-inflammatory cytokines IL-4 and IL-10. Since IL-10 effectively confers protection to mice from LPS-induced lethal endotoxemia through inhibition of proinflammatory cytokine production, we investigated whether IL-13 may also be capable of providing protection in this experimental model of endotoxic shock. A single injection of recombinant murine IL-13 (rmIL-13; 0.5-10 microg) significantly increased survival in a dose-dependent manner when a lethal i.p. injection of endotoxin was administered to BALB/c mice. This effect appeared to be IL-13 specific, since survival was not affected in mice that received heat-inactivated rmIL-13. rmIL-13 provided significant protection to mice even when given 30 min after LPS injection; however, this protection decreased in a time-dependent manner as the administration of rmIL-13 was delayed by 1, 2, and 5 h following LPS injection. The protective effect of IL-13 was correlated with significant decreases in the production of the inflammatory mediators TNF-alpha, IFN-gamma, and IL-12 as well as a decrease in the anti-inflammatory mediator IL-10. Our data suggest that IL-13 provides protection from LPS-induced lethal endotoxemia in a manner that is similar to but independent from that of IL-10, and therefore can be added to the list of cytokine immunomodulators that might be beneficial in the treatment of septic shock.
Asunto(s)
Adyuvantes Inmunológicos/uso terapéutico , Regulación hacia Abajo/inmunología , Endotoxemia/inmunología , Endotoxemia/prevención & control , Mediadores de Inflamación/antagonistas & inhibidores , Interleucina-13/uso terapéutico , Lipopolisacáridos/toxicidad , Animales , Endotoxemia/mortalidad , Femenino , Interferón gamma/biosíntesis , Interleucina-12/biosíntesis , Ratones , Ratones Endogámicos BALB C , Choque Séptico/inmunología , Choque Séptico/mortalidad , Choque Séptico/prevención & control , Factor de Necrosis Tumoral alfa/biosíntesisRESUMEN
We have previously shown that continuous administration of anti-interleukin 10 (anti-IL-10) antibodies (Abs) to BALB/c mice modifies endogenous levels of autoantibodies, tumor necrosis factor alpha (TNF-alpha), and interferon gamma, three immune mediators known to affect the development of autoimmunity in "lupus-prone" New Zealand black/white (NZB/W)F1 mice. To explore the consequences of IL-10 neutralization in NZB/W F1 mice, animals were injected two to three times per week from birth until 8-10 mo of age with anti-IL-10 Abs or with isotype control Abs. Anti-IL-10 treatment substantially delayed onset of autoimmunity in NZB/W F1 mice as monitored either by overall survival, or by development of proteinuria, glomerulonephritis, or autoantibodies. Survival at 9 mo was increased from 10 to 80% in anti-IL-10-treated mice relative to Ig isotype-treated controls. This protection against autoimmunity appeared to be due to an anti-IL-10-induced upregulation of endogenous TNF-alpha, since anti-IL-10-protected NZB/W F1 mice rapidly developed autoimmunity when neutralizing anti-TNF-alpha Abs were introduced at 30 wk along with the anti-IL-10 treatment. Consistent with the protective role of anti-IL-10 treatment in these experiments, continuous administration of IL-10 from 4 until 38 wk of age accelerated the onset of autoimmunity in NZB/W F1 mice. The same period of continuous IL-10 administration did not appear to be toxic to, or cause development of lupus-like autoimmunity in normal BALB/c mice. These data suggest that IL-10 antagonists may be beneficial in the treatment of human systemic lupus erythematosus.
Asunto(s)
Anticuerpos/administración & dosificación , Autoinmunidad/inmunología , Interleucina-10/inmunología , Animales , Autoinmunidad/efectos de los fármacos , Femenino , Ratones , Ratones Endogámicos BALB C , Pruebas de Neutralización , Factor de Necrosis Tumoral alfa/metabolismo , Regulación hacia ArribaRESUMEN
Interleukin 10 (IL-10) decreases production of IL-1, IL-6, and tumor necrosis factor alpha (TNF-alpha) in vitro, and neutralization of IL-10 in mice leads to elevation of the same monokines. We test here whether this monokine-suppressing property of IL-10 confers on it the capacity to protect mice from lipopolysaccharide-induced shock, a monokine-mediated inflammatory reaction. A single injection of 0.5-1 microgram of recombinant murine IL-10 reproducibly protected BALB/c mice from a lethal intraperitoneal injection of endotoxin. This result was obtained whether the IL-10 was administered concurrently with, or 30 min after the injection of endotoxin. The protective effect of IL-10 was reversed by prior injection of neutralizing anti-IL-10 antibodies, and correlated with a substantial decrease in endotoxin-induced TNF-alpha release. These data implicate IL-10 as a candidate for treatment of bacterial sepsis, and more generally as an effective antiinflammatory reagent.