RESUMEN
Increased levels of interferon-γ (IFN-γ) are routinely observed in the respiratory tract following influenza virus infection, yet its potential role remains unclear. We now demonstrate that influenza-induced IFN-γ restricts protective innate lymphoid cell group II (ILC2) function in the lung following challenge with the pandemic H1N1 A/CA/04/2009 (CA04) influenza virus. Specifically, IFN-γ deficiency resulted in enhanced ILC2 activity, characterized by increased production of interleukin (IL)-5 and amphiregulin, and improved tissue integrity, yet no change in ILC2 numbers, viral load or clearance. We further found that IFN-γ-deficient mice, as well as wild-type animals treated with neutralizing anti-IFN-γ antibody, exhibited decreased susceptibility to lethal infection with H1N1 CA04 influenza virus, and moreover that survival was dependent on the presence of IL-5. The beneficial effects of IFN-γ neutralization were not observed in ILC2-deficient animals. These data support the novel concept that IFN-γ can have a detrimental role in the pathogenesis of influenza through a restriction in ILC2 activity. Thus, regulation of ILC2 activity is a potential target for post-infection therapy of influenza.
Asunto(s)
Subtipo H1N1 del Virus de la Influenza A/inmunología , Interferón gamma/metabolismo , Interleucina-5/metabolismo , Linfocitos/inmunología , Infecciones por Orthomyxoviridae/inmunología , Animales , Anticuerpos Bloqueadores/metabolismo , Células Cultivadas , Susceptibilidad a Enfermedades , Inmunidad Innata , Terapia de Inmunosupresión , Interferón gamma/genética , Ratones , Ratones Noqueados , Células Th2/inmunologíaRESUMEN
Innate lymphoid cells (ILCs) are increasingly recognised as an innate immune counterpart of adaptive T-helper (TH) cells. In addition to their similar effector cytokine production, there is a strong parallel between the transcription factors that control the differentiation of T(H)1, T(H)2 and T(H)17 cells and ILC groups 1, 2 and 3, respectively. Here, we review the transcriptional circuit that specifies the development of a common ILC progenitor and its subsequent programming into distinct ILC groups. Notch, GATA-3 (GATA-binding protein 3), Nfil3 (nuclear factor interleukin-3) and Id2 (inhibitor of DNA-binding 2) are identified as early factors that suppress B- and T-cell potentials and are turned on in favour of ILC commitment. Natural killer cells, which are the cytotoxic ILCs, develop along a pathway distinct from the rest of the helper-like ILCs that are derived from a common progenitor to all helper-like ILCs (CHILPs). PLZF(-) (promyelocytic leukaemia zinc-finger) CHILPs give rise to lymphoid tissue inducer cells, while PLZF(+) CHILPs have multilineage potential and could give rise to ILCs 1, 2 and 3. Such lineage specificity is dictated by the controlled expression of T-bet (T-box expressed in T cells), RORα (retinoic acid receptor-related orphan nuclear receptor-α), RORγt (retinoic acid receptor-related orphan nuclear receptor-γt) and AHR (aryl hydrocarbon receptor). In addition to the type of transcription factors, the developmental stages at which these factors are expressed are crucial in specifying the fate of the ILCs.
Asunto(s)
Regulación de la Expresión Génica , Inmunidad Innata/fisiología , Subgrupos Linfocitarios/inmunología , Subgrupos Linfocitarios/metabolismo , Transcripción Genética , Animales , Diferenciación Celular , Linaje de la Célula , Humanos , Subgrupos Linfocitarios/citología , Transducción de Señal , Factores de Transcripción/metabolismoRESUMEN
Although type-2 immune responses evolved primarily to defend against extracellular helminths, in part through the co-opting of tissue repair and remodeling mechanisms, they are often inappropriately directed towards relatively innocuous allergens resulting in conditions including asthma, allergic rhinitis, food allergy, and atopic dermatitis. The recent discovery of group 2 innate lymphoid cells (ILC2) has increased our understanding of the initiation of these responses and the roles played by CD4(+) T helper (Th) 2 cells in their modulation. This review focuses on the important messenger role of ILC2 in translating epithelial-derived alarmins into downstream adaptive type-2 responses via dendritic cells and T cells, with special emphasis on their roles in allergic disease.
Asunto(s)
Inmunidad Adaptativa , Hipersensibilidad/inmunología , Inmunidad Innata , Linfocitos/inmunología , Animales , Humanos , Hipersensibilidad/patología , Linfocitos/patologíaRESUMEN
Helminth parasites such as the nematode Heligmosomoides polygyrus strongly inhibit T helper type 2 (Th2) allergy, as well as colitis and autoimmunity. Here, we show that the soluble excretory/secretory products of H. polygyrus (HES) potently suppress inflammation induced by allergens from the common fungus Alternaria alternata. Alternaria extract, when administered to mice intranasally with ovalbumin (OVA) protein, induces a rapid (1-48 h) innate response while also priming an OVA-specific Th2 response that can be evoked 14 days later by intranasal administration of OVA alone. In this model, HES coadministration with Alternaria/OVA suppressed early IL-33 release, innate lymphoid cell (ILC) production of IL-4, IL-5, and IL-13, and localized eosinophilia. Upon OVA challenge, type 2 ILC (ILC2)/Th2 cytokine production and eosinophilia were diminished in HES-treated mice. HES administration 6 h before Alternaria blocked the allergic response, and its suppressive activity was abolished by heat treatment. Administration of recombinant IL-33 at sensitization with Alternaria/OVA/HES abrogated HES suppression of OVA-specific responses at challenge, indicating that suppression of early Alternaria-induced IL-33 release could be central to the anti-allergic effects of HES. Thus, this helminth parasite targets IL-33 production as part of its armory of suppressive effects, forestalling the development of the type 2 immune response to infection and allergic sensitization.
Asunto(s)
Alternaria/inmunología , Inmunidad Innata/efectos de los fármacos , Linfocitos/efectos de los fármacos , Linfocitos/inmunología , Alérgenos/farmacología , Alternaria/química , Animales , Antiinflamatorios/farmacología , Antiinflamatorios/uso terapéutico , Antígenos Helmínticos/farmacología , Antígenos Helmínticos/uso terapéutico , Asma/tratamiento farmacológico , Células Cultivadas , Modelos Animales de Enfermedad , Citometría de Flujo , Inflamación , Interleucina-33 , Ratones , Sistema Respiratorio/efectos de los fármacos , Sistema Respiratorio/inmunologíaRESUMEN
The tumor necrosis factor (TNF)-family cytokine TL1A (TNFSF15) costimulates T cells and promotes diverse T cell-dependent models of autoimmune disease through its receptor DR3. TL1A polymorphisms also confer susceptibility to inflammatory bowel disease. Here, we find that allergic pathology driven by constitutive TL1A expression depends on interleukin-13 (IL-13), but not on T, NKT, mast cells, or commensal intestinal flora. Group 2 innate lymphoid cells (ILC2) express surface DR3 and produce IL-13 and other type 2 cytokines in response to TL1A. DR3 is required for ILC2 expansion and function in the setting of T cell-dependent and -independent models of allergic disease. By contrast, DR3-deficient ILC2 can still differentiate, expand, and produce IL-13 when stimulated by IL-25 or IL-33, and mediate expulsion of intestinal helminths. These data identify costimulation of ILC2 as a novel function of TL1A important for allergic lung disease, and suggest that TL1A may be a therapeutic target in these settings.
Asunto(s)
Hipersensibilidad/inmunología , Hipersensibilidad/metabolismo , Inmunidad Innata , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Animales , Citocinas/metabolismo , Modelos Animales de Enfermedad , Interleucina-13/metabolismo , Mucosa Intestinal/inmunología , Mucosa Intestinal/metabolismo , Mucosa Intestinal/microbiología , Mucosa Intestinal/patología , Pulmón/inmunología , Pulmón/metabolismo , Pulmón/patología , Mastocitos/inmunología , Mastocitos/metabolismo , Ratones , Ratones Noqueados , Unión Proteica , Miembro 25 de Receptores de Factores de Necrosis Tumoral/metabolismo , Miembro 15 de la Superfamilia de Ligandos de Factores de Necrosis TumoralRESUMEN
BACKGROUND: The regulation and function of IgE in healthy individuals and in antigen-naïve animals is not well understood. IL-33 administration increases serum IgE in mice with unknown mechanism. We tested the hypothesis that IL-33 provides an antigen-independent stimulus for IgE production and mast cell degranulation. METHODS: IL-33 was administered to naïve wild-type (WT), nude and ST2(-/-) , IL-4(-/-) , IL4Rα(-/-) and T-or B-cell-specific IL-4Rα(-/-) mice. IgE and cytokines were quantified by ELISA. T- and B-lymphocyte numbers and CD40L expression were determined by flow cytometry. Anaphylaxis was measured by temperature, mast cell degranulation and histamine release. RESULTS: IL-33 enhanced IgE production in naïve WT, T-IL-4Rα(-/-) but not in ST2(-/-) , IL-4(-/-) , IL-4Rα(-/-) or B-cell-specific IL-4Rα(-/-) mice, demonstrating IL-33 specificity and IL-4 dependency. Moreover, IL-4 was required for IL-33-induced B-cell proliferation and T-cell CD40L expression, which promotes IgE production. IL-33-induced IL-4 production was mainly from innate cells including mast cells and eosinophils. IL-33 increased mast cell surface IgE and triggered degranulation and systemic anaphylaxis in allergen-naïve WT but not in IL-4Rα(-/-) mice. CONCLUSION: IL-33 amplifies IgE synthesis and triggers anaphylaxis in naïve mice via IL-4, independent of allergen. IL-33 may play an important role in nonatopic allergy and idiopathic anaphylaxis.
Asunto(s)
Degranulación de la Célula , Inmunoglobulina E/biosíntesis , Interleucina-4/inmunología , Interleucinas/inmunología , Interleucinas/farmacología , Mastocitos/fisiología , Anafilaxia/etiología , Anafilaxia/inmunología , Animales , Degranulación de la Célula/inmunología , Citometría de Flujo , Liberación de Histamina , Inmunoglobulina E/efectos de los fármacos , Interleucina-33 , Interleucina-4/genética , Interleucina-4/metabolismo , Interleucinas/metabolismo , Ratones , Ratones Endogámicos BALB C , Ratones Endogámicos C57BL , Ratones DesnudosRESUMEN
BACKGROUND: Interleukin (IL)-25 (IL-17E) is a potent inducer of the type-2 immune effector response. Previously we have demonstrated that a neutralizing anti-IL-25 antibody, given during the establishment of ovalbumin-specific lung allergy, abrogates airways hyperreactivity. OBJECTIVE: Blocking IL-25 results in the suppression of IL-13, a cytokine known to exacerbate pulmonary inflammation, and an unexpected reciprocal increase in IL-17A. The role of IL-17A in asthma is complex with reports of both pro-inflammatory and anti-inflammatory functions. Our aim was to determine the influence of IL-17A in regulating IL-25-dependent lung allergy. METHOD: Neutralizing antibodies to IL-25 and/or IL-17A were administered during an experimental model of allergic asthma. Bronchoalveolar cell infiltrates and lung cytokine production were determined to assess lung inflammation. Invasive plethysmography was undertaken to measure lung function. RESULTS: Neutralization of IL-25 correlated with a decrease in IL-13 levels and an increase in IL-17A production, and an accompanying prevention of airway hyperresponsiveness (AHR). Notably, the blocking of IL-17A reversed the protective effects of treating with anti-IL-25 antibodies, resulting in the re-expression of several facets of the lung inflammatory response, including IL-13 and eotaxin production, eosinophilia and AHR. Using mice over-expressing IL-13 we demonstrate that treatment of these mice with anti-IL-25 fails to suppress IL-13 levels and in turn IL-17A levels remain suppressed. CONCLUSIONS AND CLINICAL RELEVANCE: IL-13 is known to be an important inducer of lung inflammation, causing goblet cell hyperplasia and promoting airways hyperreactivity. Our data now demonstrate that IL-13 also plays an important role in the genesis of lung inflammation downstream of IL-25 by suppressing a protective IL-17A response. These findings also highlight the important reciprocal interplay of the IL-17 family members, IL-25 and IL-17A, in regulating allergic lung responses and suggest that the balance of IL-17A, together with IL-25, will be an important consideration in the treatment of allergic asthma.
Asunto(s)
Hiperreactividad Bronquial/inmunología , Interleucina-13/metabolismo , Interleucina-17/metabolismo , Hipersensibilidad Respiratoria/inmunología , Animales , Asma/inmunología , Asma/metabolismo , Asma/fisiopatología , Citocinas/biosíntesis , Citocinas/metabolismo , Femenino , Humanos , Pulmón/inmunología , Pulmón/metabolismo , Masculino , Ratones , Ratones Endogámicos BALB C , Ratones Noqueados , Ovalbúmina/inmunología , Neumonía/inmunología , Células Th2/inmunologíaRESUMEN
BACKGROUND: Initial studies suggested that polymorphisms in Tim1 and Tim3 contribute to the development of airway hyperreactivity (AHR) in an acute mouse model of asthma. This was also mirrored in human genetic studies where polymorphisms in Tim1 and Tim3 have been associated with atopic populations. OBJECTIVE: Further studies using anti-Tim1 or -Tim3 antibodies, or Tim fusion proteins, have also suggested that these molecules may function as regulators of type-1 and type-2 immunity. However, their role in the development of AHR and airway inflammation remains unclear. Given the proposed roles for Tim1 and Tim3 in type-1 and type-2 responses, we sought to determine whether these molecules were important in regulating antigen-driven lung allergy and inflammation. METHOD: We used Tim1- and Tim3-deficient mice and determined how the development of allergic lung inflammation was affected. RESULTS: AHR was induced normally in the absence of both Tim1 and Tim3, although Tim1-deficient mice did show a small but significant decrease in cell infiltration in the lung and blood eosinophilia. Although Tim3 was expressed on CD4(+) T cells in the allergic lung, Tim1 expression was restricted to CD86(+) B cells. CONCLUSIONS AND CLINICAL RELEVANCE: Thus, Tim1 and Tim3 are not essential for the induction of the type-2 response in lung allergy. This is contrary to what was proposed in a number of other studies using neutralizing and activating antibodies and questions the clinical relevance of Tim1 and Tim3 for novel allergy therapies.
Asunto(s)
Asma/metabolismo , Asma/fisiopatología , Hipersensibilidad Inmediata/metabolismo , Hipersensibilidad Inmediata/fisiopatología , Proteínas de la Membrana/metabolismo , Receptores Virales/metabolismo , Animales , Asma/inmunología , Linfocitos B/inmunología , Linfocitos B/metabolismo , Antígeno B7-2/metabolismo , Hiperreactividad Bronquial/inmunología , Hiperreactividad Bronquial/metabolismo , Hiperreactividad Bronquial/fisiopatología , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Modelos Animales de Enfermedad , Receptor Celular 1 del Virus de la Hepatitis A , Receptor 2 Celular del Virus de la Hepatitis A , Humanos , Hipersensibilidad Inmediata/inmunología , Inflamación/inmunología , Inflamación/metabolismo , Inflamación/fisiopatología , Pulmón , Proteínas de la Membrana/deficiencia , Proteínas de la Membrana/genética , Ratones , Ratones Endogámicos BALB C , Receptores Virales/deficiencia , Receptores Virales/genéticaRESUMEN
The present study aimed to determine whether the T-helper cell type 2-derived cytokines, interleukin (IL)-4 and -13, can modulate the lung response to ozone exposure. IL-13(-/-), IL-4/13(-/-) and IL-13-overexpressing transgenic (Tg) mice were exposed to ozone (3 ppm; 3 h) or air. Wild-type (Wt) Balb/c mice and transgenic-negative littermates (IL-13Wt) were used as controls for gene-deficient and IL-13Tg mice, respectively. IL-4/13(-/-) and IL-13(-/-) mice developed a lesser degree of ozone-induced airway hyperresponsiveness (AHR) while IL-13Tg mice developed a greater degree of AHR compared with ozone-exposed wild-type or IL-13Wt mice, respectively. Ozone caused a time-dependent increase of bronchoalveolar lavage (BAL) neutrophils and macrophages in wild-type mice, maximal at 20-24 h, which was attenuated in the IL-13(-/-) and IL-4/13(-/-) mice. In IL-13Tg mice, there was a greater increase in BAL neutrophils after ozone exposure compared with IL-13Wt mice. Using quantitative real-time PCR, ozone-induced mRNA expression for IL-6 and keratinocyte chemokine was further enhanced in IL-13(-/-) and IL-4/13(-/-) mice, and was inhibited in IL-13Tg mice. Macrophage inflammatory protein (MIP)-3alpha/CCL20 expression was enhanced after ozone exposure in wild-type mice, inhibited in IL-13(-/-) and IL-4/13(-/-) mice, while in IL-13Tg mice it was enhanced. A similar pattern of expression was observed with lipopolysaccharide-induced cytokine (LIX/CXCL5/ENA-78) expression. In conclusion, interleukin-13 augments ozone-induced airway hyperresponsiveness and neutrophilic inflammation, possibly through modulation of certain cytokines induced by ozone exposure.
Asunto(s)
Hiperreactividad Bronquial/inmunología , Interleucina-13/inmunología , Ozono/efectos adversos , Animales , Hiperreactividad Bronquial/inducido químicamente , Quimiocina CCL20/metabolismo , Interleucina-4/inmunología , Ratones , Ratones TransgénicosRESUMEN
Agonists of the allosteric benzodiazepine site of GABAA receptors bind at the interface of the alpha and gamma subunits. Here, we tested the in vivo contribution of the gamma2 subunit to the actions of zolpidem, an alpha1 subunit selective benzodiazepine agonist, by generating mice with a phenylalanine (F) to isoleucine (I) substitution at position 77 in the gamma2 subunit. The gamma2F77I mutation has no major effect on the expression of GABAA receptor subunits in the cerebellum. The potency of zolpidem, but not that of flurazepam, for the inhibition of [3H]flunitrazepam binding to cerebellar membranes is greatly reduced in gamma2I77/I77 mice. Zolpidem (1 microM) increased both the amplitude and decay of miniature inhibitory postsynaptic currents (mIPSCs) in Purkinje cells of control C57BL/6 (34% and 92%, respectively) and gamma2F77/F77 (20% and 84%) mice, but not in those of gamma2F77I mice. Zolpidem tartrate had no effect on exploratory activity (staircase test) or motor performance (rotarod test) in gamma2I77/I77 mice at doses up to 30 mg/kg (i.p.) that strongly sedated or impaired the control mice. Flurazepam was equally effective in enhancing mIPSCs and disrupting performance in the rotarod test in control and gamma2I77/I77 mice. These results show that the effect of zolpidem, but not flurazepam, is selectively eliminated in the brain by the gamma2F77I point mutation.
Asunto(s)
Agonistas del GABA/farmacología , Mutación Puntual , Piridinas/farmacología , Receptores de GABA-A/genética , Sustitución de Aminoácidos , Animales , Secuencia de Bases , Cartilla de ADN , Flunitrazepam/farmacocinética , Ratones , Ratones Mutantes , Polimorfismo de Nucleótido Simple/genética , ZolpidemRESUMEN
The cerebellum maintains balance and orientation, refines motor action, stores motor memories, and contributes to the timing aspects of cognition. We generated two mouse lines for making Cre recombinase-mediated gene disruptions largely confined to adult cerebellar granule cells. For this purpose we chose the GABA(A) receptor alpha6 subunit gene, whose expression marks this cell type. Here we describe mouse lines expressing Cre recombinase generated by 1) Cre knocked into the native alpha6 subunit gene by homologous recombination in embryonic stem cells; and 2) Cre recombined into an alpha6 subunit gene carried on a bacterial artificial chromosome (BAC) genomic clone. The fidelity of Cre expression was tested by crossing the mouse lines with the ROSA26 reporter mice. The particular alpha6BAC clone we identified will be valuable for delivering other gene products to cerebellar granule cells.
Asunto(s)
Cerebelo/enzimología , Gránulos Citoplasmáticos/enzimología , Recombinasas/genética , Animales , Secuencia de Bases , Cromosomas Artificiales Bacterianos , Cartilla de ADN , Inmunohistoquímica , RatonesRESUMEN
BACKGROUND: Interleukin-13 is believed to be important in asthmatic inflammation and airway hyper-reactivity. OBJECTIVE: To investigate the role of IL-13 in chronic asthma, using an improved experimental model of asthma that reproduces most of the morphological features of the human disease. METHODS: BALB/c mice or gene-targeted mice deficient in their ability to produce IL-13 or the IL-4 receptor alpha-chain (IL-4Ralpha) were sensitized to ovalbumin and exposed to aerosolized antigen for 30 min/day on 3 days/week for 6 weeks. Intraepithelial eosinophils, accumulation of chronic inflammatory cells in the airway wall, subepithelial fibrosis, epithelial hypertrophy and numbers of mucous cells were quantified histomorphometrically. Airway hyper-reactivity (AHR) to a cholinergic agonist was assessed by barometric plethysmography. RESULTS: Compared with wild-type animals, IL-13 -/- mice exhibited diminished accumulation of eosinophils and chronic inflammatory cells, as well as reduced subepithelial fibrosis, epithelial hypertrophy and mucous cell hyperplasia (P < 0.01 for all comparisons). In contrast, AHR was still demonstrable in IL -13 -/- mice. In IL-4Ralpha -/- mice the inflammatory response, subepithelial fibrosis and AHR were similar to wild-type mice, although the receptor-deficient mice had significantly less epithelial hypertrophy and mucous cell hyperplasia. CONCLUSION: These results imply a critical role for IL-13 in accumulation of intraepithelial eosinophils in chronic asthma, as well as in epithelial and subepithelial remodelling. In addition, they suggest that in chronic asthma, IL-13 may be capable of signalling via a pathway that does not involve IL-4Ralpha.