RESUMO
Antibodies play a central role in the immune defense against SARS-CoV-2. Emerging evidence has shown that nonneutralizing antibodies are important for immune defense through Fc-mediated effector functions. Antibody subclass is known to affect downstream Fc function. However, whether the antibody subclass plays a role in anti-SARS-CoV-2 immunity remains unclear. Here, we subclass-switched eight human IgG1 anti-spike monoclonal antibodies (mAbs) to the IgG3 subclass by exchanging their constant domains. The IgG3 mAbs exhibited altered avidities to the spike protein and more potent Fc-mediated phagocytosis and complement activation than their IgG1 counterparts. Moreover, combining mAbs into oligoclonal cocktails led to enhanced Fc- and complement receptor-mediated phagocytosis, superior to even the most potent single IgG3 mAb when compared at equivalent concentrations. Finally, in an in vivo model, we show that opsonic mAbs of both subclasses can be protective against a SARS-CoV-2 infection, despite the antibodies being nonneutralizing. Our results suggest that opsonic IgG3 oligoclonal cocktails are a promising idea to explore for therapy against SARS-CoV-2, its emerging variants, and potentially other viruses.
Assuntos
COVID-19 , Imunoglobulina G , Humanos , Opsonização , SARS-CoV-2 , Fagocitose , Anticorpos Monoclonais/farmacologiaRESUMO
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific neutralizing antibodies (NAbs) lack cross-reactivity between SARS-CoV species and variants and fail to mediate long-term protection against infection. The maintained protection against severe disease and death by vaccination suggests a role for cross-reactive T cells. We generated vaccines containing sequences from the spike or receptor binding domain, the membrane and/or nucleoprotein that induced only T cells, or T cells and NAbs, to understand their individual roles. In three models with homologous or heterologous challenge, high levels of vaccine-induced SARS-CoV-2 NAbs protected against neither infection nor mild histological disease but conferred rapid viral control limiting the histological damage. With no or low levels of NAbs, vaccine-primed T cells, in mice mainly CD8+ T cells, partially controlled viral replication and promoted NAb recall responses. T cells failed to protect against histological damage, presumably because of viral spread and subsequent T cell-mediated killing. Neither vaccine- nor infection-induced NAbs seem to provide long-lasting protective immunity against SARS-CoV-2. Thus, a more realistic approach for universal SARS-CoV-2 vaccines should be to aim for broadly cross-reactive NAbs in combination with long-lasting highly cross-reactive T cells. Long-lived cross-reactive T cells are likely key to prevent severe disease and fatalities during current and future pandemics.
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Anticorpos Neutralizantes , Vacinas contra COVID-19 , COVID-19 , Animais , Humanos , Camundongos , Anticorpos Antivirais , Linfócitos T CD8-Positivos , COVID-19/prevenção & controle , Vacinas contra COVID-19/efeitos adversos , SARS-CoV-2 , Vacinas ViraisRESUMO
BACKGROUND: Neuropeptides, such as substance P (SP), have long been seen as mediators of widespread continuous airway inflammation, a process known as neurogenic inflammation. However, this has been difficult to demonstrate clinically, suggesting an alternative role for these signaling molecules. OBJECTIVES: We sought to examine the role of SP in nasal infection by assessing the release of SP in response to viral stimulation and characterizing the effects of SP on innate immunity, with the latter reflected in changes in local Toll-like receptor (TLR) expression. METHODS: The distribution of SP and TLRs in the nasal mucosa and local airway neurons was assessed with immunohistochemistry. The TLR7 agonists R-837 and R-848 were used to mimic a viral insult in the upper airways represented by primary human nasal epithelial cells (HNECs) and murine nasal epithelial cells (MNECs) and isolated murine trigeminal ganglial neurons. SP release from HNECs, MNECs, and trigeminal ganglial neurons was quantified with EIA. The effects of SP on TLR expression on HNECs were determined by using flow cytometry and confocal microscopy. RESULTS: SP was released from the sensory neurons, MNECs, and HNECs within 15 minutes of local TLR7 stimulation. Subsequently, stimulation with SP induced upregulation of TLR expression in HNECs within 30 minutes through induction of TLR movement within HNECs. Upregulation of TLR expression was not evident when cells were treated with the neurokinin 1 receptor antagonist aprepitant before SP stimulation. CONCLUSIONS: This highlights a novel role for sensory neuropeptides as acute and local mediators of pathogen-driven inflammation, rapidly priming innate immune defenses in the airway.
Assuntos
Células Epiteliais/imunologia , Imunidade Inata , Mucosa Nasal/imunologia , Neurônios Aferentes/imunologia , Substância P/imunologia , Animais , Células Epiteliais/citologia , Humanos , Glicoproteínas de Membrana/imunologia , Camundongos , Mucosa Nasal/citologia , Mucosa Nasal/inervação , Neurônios Aferentes/citologia , Receptor 7 Toll-Like/imunologiaRESUMO
Toll-like receptor (TLR) 7 agonists are known to reduce allergic airway inflammation. Their recently reported ability to rapidly relax airways has further increased their interest in the treatment of pulmonary disease. However, the mechanisms behind this effect are not fully understood. The present study, therefore, aimed to determine whether airway smooth muscle (ASM)-dependent mechanisms could be identified. TLR7 agonists were added to guinea pig airways following precontraction with carbachol in vitro or histamine in vivo. Pharmacological inhibitors were used to dissect conventional pathways of bronchodilation; tetrodotoxin was used or bilateral vagotomy was performed to assess neuronal involvement. Human ASM cells (HASMCs) were employed to determine the effect of TLR7 agonists on intracellular Ca(2+) ([Ca(2+)]i) mobilization. The well-established TLR7 agonist imiquimod rapidly relaxed precontracted airways in vitro and in vivo. This relaxation was demonstrated to be independent of nitric oxide, carbon monoxide, and cAMP signaling, as well as neuronal activity. A limited role for prostanoids could be detected. Imiquimod induced [Ca(2+)]i release from endoplasmic reticulum stores in HASMCs, inhibiting histamine-induced [Ca(2+)]i The TLR7 antagonist IRS661 failed to inhibit relaxation, and the structurally dissimilar agonist CL264 did not relax airways or inhibit [Ca(2+)]i This study shows that imiquimod acts directly on ASM to induce bronchorelaxation, via a TLR7-independent release of [Ca(2+)]i The effect is paralleled by other bronchorelaxant compounds, like chloroquine, which, like imiquimod, but unlike CL264, contains the chemical structure quinoline. Compounds with quinoline moieties may be of interest in the development of multifunctional drugs to treat pulmonary disease.
Assuntos
Aminoquinolinas/farmacologia , Broncodilatadores/farmacologia , Receptor 7 Toll-Like/agonistas , Animais , Asma/tratamento farmacológico , Bronquíolos/efeitos dos fármacos , Bronquíolos/fisiologia , Sinalização do Cálcio , Células Cultivadas , Avaliação Pré-Clínica de Medicamentos , Cobaias , Humanos , Imiquimode , Masculino , Miócitos de Músculo Liso/efeitos dos fármacos , Miócitos de Músculo Liso/fisiologiaAssuntos
Betacoronavirus , Infecções por Coronavirus , Pandemias , Pneumonia Viral , COVID-19 , Humanos , Proteínas do Nucleocapsídeo , SARS-CoV-2RESUMO
BACKGROUND: Allergen-specific immunotherapy represents the only disease-modifying treatment for allergic diseases. We and others have previously demonstrated that intralymphatic immunotherapy (ILIT), a less time-consuming alternative to conventional subcutaneous immunotherapy (SCIT), is safe and effective. However, this has recently been disputed. The aim of this study was therefore to expand our previous trial, further assessing the safety and efficacy of ILIT. METHODS: Thirty-six patients with pollen-induced rhinoconjunctivitis were randomised to receive three intralymphatic inguinal injections of active allergen (1000 SQ-U birch- or grass-pollen) or placebo. Clinical effects, safety and circulating immunological markers were assessed before, 4 weeks after treatment and at the end of the consecutive pollen season. RESULTS: No moderate or severe reactions were recorded following ILIT. Patients receiving active ILIT experienced a significant improvement in self-recorded seasonal allergic symptoms, as compared to placebo (p = 0.05). In a subgroup of these patients ("improved"), a reduction in nasal symptoms following nasal allergen provocation was also demonstrated. No changes in total IgE or IgG4 were found. However, the affinity of allergen specific IgG4 following active treatment was significantly increased, as compared to non-improved patients (p = 0.04). This could be correlated with clinical improvement, on an individual level. CONCLUSIONS: This double-blinded placebo-controlled study confirms that ILIT is a safe and effective treatment for pollen-induced rhinoconjunctivitis, markedly reducing seasonal allergic symptoms. TRIAL REGISTRATION: EudraCT: 2009-016815-39.
Assuntos
Alérgenos/administração & dosagem , Conjuntivite/imunologia , Conjuntivite/terapia , Rinite Alérgica Sazonal/imunologia , Rinite Alérgica Sazonal/terapia , Adulto , Alérgenos/imunologia , Dessensibilização Imunológica/métodos , Método Duplo-Cego , Feminino , Humanos , Injeções Intralinfáticas/métodos , Masculino , Pessoa de Meia-Idade , Efeito Placebo , Resultado do TratamentoRESUMO
RATIONALE: Cardiac monitoring has often been identified as an area of overutilization and remains a limited resource in many hospitals. With the aim of reducing telemetry overuse, we added clinical decision support to our health system's telemetry order with guidance on appropriate indications for monitoring. The new order requires selection of an appropriate clinical indication. AIMS AND OBJECTIVES: In this study, we aimed to understand provider engagement with this tool by assessing concordance between selected indications within the order and the clinical presence of those conditions as documented within the patient chart. METHODS: We randomly selected 100 telemetry orders from July to October 2022 across four different hospitals at NYU Langone Health. Two independent, blinded reviewers used a structured protocol to identify documentation of actual indications for telemetry in each selected chart. We calculated the rate of concordance between indications selected in the order and indications that were determined to be clinically present on chart review. RESULTS: There were 30,839 telemetry orders placed during the study timeframe. Overall concordance between the selection within the order and the actual indication was 48% (95% confidence interval [CI], 38.21%-57.79%). We observed especially low concordance rates for vague indications, such as 'Other', and for 'Confirmed Stroke', which was the only indication allowing for indefinite telemetry. CONCLUSION: The overall low concordance suggests a disconnect between the support tool and clinical practice. Providers are more likely to select an indication that reduces downstream work regardless of a patient's true clinical indication.
Assuntos
Sistemas de Apoio a Decisões Clínicas , Telemetria , Telemetria/métodos , Telemetria/estatística & dados numéricos , Humanos , Estudos Retrospectivos , Centros Médicos Acadêmicos , Masculino , Uso Excessivo dos Serviços de Saúde/prevenção & controle , Uso Excessivo dos Serviços de Saúde/estatística & dados numéricosRESUMO
BACKGROUND: The recorded use of iodine in medicine, dates to 5000 BC. Molecular iodine (I2 ) has been claimed to exert an antineoplastic effect that triggers apoptotic and re-differentiation mechanisms in different types of cancer cells in animal studies. Hitherto, all experiments published have been carried out with I2 diluted in water preparations resulting in the administration of ionized iodide, either alone or in combination with low levels of I2 . To maximize the levels of I2 by avoiding water solutions we have managed to develop a colloidal nano particle (NP) loaded with I2 with a Z-average of 7-23 nm with remarkable stability, preferable osmolality and commercial applicability. AIMS: Here we report the results from formulation and pre-clinical studies with the rationale: a) to find a tolerable dose of the I2 NP system delivered intravenously or per-orally, and b) to determine if the tolerable doses are efficacious in murine models of cancer. METHODS AND RESULTS: A novel drug delivery system with I2 NP was formulated and murine cancer models with CT26, MDA-MB-231 and LL/2 cells were used to analyse the efficacy. Despite the formulation challenges we were successful in constructing stable NPs loaded with I2 which have convincing commercial applicability. We conclude that administration of the NP I2 drug delivery system: 1. Blunted tumour growth in a xenograft breast cancer model; 2. Had a significant effect on survival in the orthotopic, syngeneic lung metastasis model; 3. Showed reduced tumour burden in post-mortem evaluation and; 4. Was associated with low degree of side effects. CONCLUSIONS: Taken all together, our findings indicate that the NP I2 drug delivery system may serve as a novel effective cancer treatment with low degree of side effects. This is something which needs further exploration including confirmation in future clinical trials.
Assuntos
Antineoplásicos , Efeitos Colaterais e Reações Adversas Relacionados a Medicamentos , Iodo , Nanopartículas , Neoplasias , Camundongos , Humanos , Animais , Iodo/efeitos adversos , Antineoplásicos/efeitos adversos , Sistemas de Liberação de Medicamentos/métodos , Neoplasias/tratamento farmacológicoRESUMO
Removal of genes coding for major parts of capsid (C), premembrane (prM), and envelope (E) proteins on the flavivirus genome aborts the production of infectious virus particles where the remaining genome forms a replicon that retains replicability in host cells. The C-prM-E proteins can also be expressed in trans with the flavivirus replicons to generate single-round infectious replicon virus-like particles (RVPs). In this study, we characterized the use of RVPs based on the Kunjin strain of WNV (WNVKUN) as a putative WNV vaccine candidate. In addition, the WNVKUN C-prM-E genes were substituted with the Crimean-Congo hemorrhagic fever virus (CCHFV) genes encoding the glycoproteins Gn and Gc to generate a WNVKUN replicon expressing the CCHFV proteins. To generate RVPs, the WNVKUN replicon was transfected into a cell line expressing the WNVKUN C-prM-E. Using immunoblotting and immunofluorescence assays, we showed that the replicon can express the CCHFV Gn and Gc proteins and the RVPs can transduce cells to express WNVKUN proteins and the CCHFV Gn and Gc proteins. Our study also revealed that these RVPs have potential as a vaccine platform with low risk of recombination as it infects cells only in one cycle. The immunization of mice with the RVPs resulted in high seroconversion to both WNV E and NS1 but limited seroconversion to CCHFV Gn and Gc proteins. Interestingly, we found that there was enhanced production of WNV E, NS1 antibodies, and neutralizing antibodies by the inclusion of CCHFV Gc and Gn into WNVKUN RVPs. Thus, this study indicates a complementary effect of the CCHFV Gn and Gc proteins on the immunogenicity by WNVKUN RVPs, which may be applied to develop a future vaccine against the WNV.
RESUMO
New variants in the SARS-CoV-2 pandemic are more contagious (Alpha/Delta), evade neutralizing antibodies (Beta), or both (Omicron). This poses a challenge in vaccine development according to WHO. We designed a more universal SARS-CoV-2 DNA vaccine containing receptor-binding domain loops from the huCoV-19/WH01, the Alpha, and the Beta variants, combined with the membrane and nucleoproteins. The vaccine induced spike antibodies crossreactive between huCoV-19/WH01, Beta, and Delta spike proteins that neutralized huCoV-19/WH01, Beta, Delta, and Omicron virus in vitro. The vaccine primed nucleoprotein-specific T cells, unlike spike-specific T cells, recognized Bat-CoV sequences. The vaccine protected mice carrying the human ACE2 receptor against lethal infection with the SARS-CoV-2 Beta variant. Interestingly, priming of cross-reactive nucleoprotein-specific T cells alone was 60% protective, verifying observations from humans that T cells protect against lethal disease. This SARS-CoV vaccine induces a uniquely broad and functional immunity that adds to currently used vaccines.
Assuntos
COVID-19 , Vacinas de DNA , Vacinas Virais , Enzima de Conversão de Angiotensina 2/genética , Animais , Anticorpos Neutralizantes , Anticorpos Antivirais , COVID-19/prevenção & controle , Vacinas contra COVID-19 , Humanos , Camundongos , Nucleoproteínas , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus/genética , Linfócitos T , Vacinas de DNA/genética , Proteínas do Envelope Viral/química , Proteínas do Envelope Viral/genética , Vacinas Virais/genéticaRESUMO
Inhibitors of viral cell entry based on poly(styrene sulfonate) and its core-shell nanoformulations based on gold nanoparticles are investigated against a panel of viruses, including clinical isolates of SARS-CoV-2. Macromolecular inhibitors are shown to exhibit the highly sought-after broad-spectrum antiviral activity, which covers most analyzed enveloped viruses and all of the variants of concern for SARS-CoV-2 tested. The inhibitory activity is quantified in vitro in appropriate cell culture models and for respiratory viral pathogens (respiratory syncytial virus and SARS-CoV-2) in mice. Results of this study comprise a significant step along the translational path of macromolecular inhibitors of virus cell entry, specifically against enveloped respiratory viruses.
Assuntos
Tratamento Farmacológico da COVID-19 , Nanopartículas Metálicas , Animais , Antivirais/farmacologia , Antivirais/uso terapêutico , Ouro , Camundongos , SARS-CoV-2 , Internalização do VírusRESUMO
BACKGROUND: Substance P (SP) and toll-like receptors (TLRs) contribute to airway disease, particularly during viral infection. We recently demonstrated that SP can act as an initial response to viral stimuli in the upper airway by upregulating TLRs in the nasal epithelia (the SP-TLR axis). Patients with allergic rhinitis (AR) suffer from prolonged airway infections. The aim of the present study was to examine if patients with AR exhibit a disturbance in the SP-TLR axis. METHOD: Human nasal biopsies and human nasal epithelial cells (HNEC) from healthy volunteers and patients with AR were cultured in the presence of SP. Epithelial expression of TLR4, neutral endopeptidase (NEP) and neurokinin 1 (NK1) were evaluated with flow cytometry and/or quantitative polymerase chain reaction after 30 min to 24 h. The effect of SP on nasal lipopolysaccharide-induced interleukin-8 (IL-8) release was investigated. RESULTS: SP stimulation of tissue from healthy volunteers resulted in a transient increase of the TLR4 expression, whereas stimulation of AR patient-derived material led to a delayed and prolonged upregulation of TLR4. NEP expression in HNEC was lower in AR than healthy controls whereas NK1 receptor expression was increased. SP pretreatment increased TLR4-dependent IL-8 expression in healthy controls, but not in AR. CONCLUSIONS: SP-induced regulation of TLR4 in the human nasal mucosa is disturbed in AR. An altered SP-mediated innate immune response may contribute to the dysfunctional and often prolonged responses to infection in AR.
RESUMO
Spike-specific antibodies are central to effective COVID19 immunity. Research efforts have focused on antibodies that neutralize the ACE2-Spike interaction but not on non-neutralizing antibodies. Antibody-dependent phagocytosis is an immune mechanism enhanced by opsonization, where typically, more bound antibodies trigger a stronger phagocyte response. Here, we show that Spike-specific antibodies, dependent on concentration, can either enhance or reduce Spike-bead phagocytosis by monocytes independently of the antibody neutralization potential. Surprisingly, we find that both convalescent patient plasma and patient-derived monoclonal antibodies lead to maximum opsonization already at low levels of bound antibodies and is reduced as antibody binding to Spike protein increases. Moreover, we show that this Spike-dependent modulation of opsonization correlate with the outcome in an experimental SARS-CoV-2 infection model. These results suggest that the levels of anti-Spike antibodies could influence monocyte-mediated immune functions and propose that non-neutralizing antibodies could confer protection to SARS-CoV-2 infection by mediating phagocytosis.
Assuntos
Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/imunologia , COVID-19/imunologia , Opsonização/imunologia , Fagocitose/imunologia , SARS-CoV-2/imunologia , Glicoproteína da Espícula de Coronavírus/imunologia , Anticorpos Monoclonais/imunologia , Linhagem Celular , Células HEK293 , Humanos , Testes de Neutralização/métodosRESUMO
We recently identified a novel neuroimmune mechanism in the nasal mucosa, in which activation of neuronal Tolllike receptor (TLR) 7 results in upregulation of epithelial TLRs, via release of substance P. In the present study, we assessed whether intranasal challenge with the TLR7 agonist R837 additionally activated neurons in the central nervous system. Within one hour, R837 induced activation of the nucleus of the solitary tract, as well as a small increase in nasal IL6, but otherwise in the absence of an overt inflammatory response. It is tempting to speculate that it might be a direct interaction of R837 with trigeminal neurons in order to alert the central nervous system of invading pathogens.
Assuntos
Tronco Encefálico/fisiologia , Sistema Nervoso Central/imunologia , Mucosa Nasal/fisiologia , Receptor 7 Toll-Like/metabolismo , Animais , Tronco Encefálico/imunologia , Sistema Nervoso Central/fisiologia , Masculino , Camundongos Endogâmicos C57BL , Mucosa Nasal/imunologia , Neurônios/imunologia , Proteínas Proto-Oncogênicas c-fos/metabolismoRESUMO
Kunjin virus (KUNV) is an attenuated strain of the severe neurotropic West Nile virus (WNV). The virus has a single-strand positive-sense RNA genome that encodes a polyprotein. Following gene expression, the polyprotein is cleaved into structural proteins for viral packaging and nonstructural proteins for viral replication and expression. Removal of the structural genes generate subgenomic replicons that maintain replication capacity. Co-expression of these replicons with the viral structural genes produces reporter virus-like particles (RVPs) which infect cells in a single round. In this study, we aimed to develop a system to generate multivalent RVPs based on KUNV to elicit an immune response against different viruses. We selected the Ebola virus (EBOV) glycoprotein (GP) and the matrix protein (VP40) genes, as candidates to be delivered by KUNV RVPs. Initially, we enhanced the production of KUNV RVPs by generating a stable cell line expressing the KUNV packaging system comprising capsid, precursor membrane, and envelope. Transfection of the DNA-based KUNV replicon into this cell line resulted in an enhanced RVP production. The replicon was expressed in the stable cell line to produce the RVPs that allowed the delivery of EBOV GP and VP40 genes into other cells. Finally, we immunized BALB/cN mice with RVPs, resulting in seroconversion for EBOV GP, EBOV VP40, WNV nonstructural protein 1, and WNV E protein. Thus, our study shows that KUNV RVPs may function as a WNV vaccine candidate and RVPs can be used as a gene delivery system in the development of future EBOV vaccines.
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Chronic rhinosinusitis with nasal polyps (CRSwNP) is a widespread disease causing obstruction of the nasal cavity. Its cause remains unclear. The transforming growth-factor beta (TGF-ß) superfamily and their receptors, termed Activin receptor-like kinases (ALKs), have recently been suggested to play a role in local airway inflammation, but have so far not been evaluated in human nasal epithelial cells (HNECs) from CRSwNP patients. We demonstrated that ALK1-7 were expressed in the nasal polyp epithelium, and the expression of ALK1-6 was markedly elevated in polyps compared to nasal mucosa from healthy controls. Stimulation with the ALK ligand TGF-ß1 decreased Ki67 expression in HNECs from CRSwNP patients, not evident in controls. Likewise, TGF-ß1, Activin A and Activin B, all ALK ligands, decreased IL-8 release and Activin A and Activin B reduced ICAM1 expression on HNECs from CRSwNP patients, not seen in controls. Pre-stimulation with TGF-ß1, Activin A, BMP4 and Activin B attenuated a TNF-α-induced ICAM1 upregulation on HNECs of CRSwNP. No effect was evident in controls. In conclusion, an increased expression of ALK1-6 was found on polyp epithelial cells and ligand stimulation appeared to reduce proliferation and local inflammation in polyps.
Assuntos
Receptores de Ativinas/metabolismo , Células Epiteliais/fisiologia , Mucosite/patologia , Pólipos Nasais/complicações , Sinusite/patologia , Adulto , Biópsia , Células Cultivadas , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Modelos Biológicos , Mucosite/prevenção & controle , Sinusite/prevenção & controleRESUMO
Cannabinoids are known to inhibit neuronal activity and have significant immunomodulatory effects which suggest a role in inflammatory airway diseases. In the present study, we tested the hypothesis that cannabinoids have both acute and chronic modulatory effects on nerve-mediated contractions in NGF-induced airway inflammation. Contractions induced by electrical field stimulation (EFS) were examined in tracheal segments isolated from male BALB/c mice. Tissues were both used fresh or after four days of culture with NGF to induce airway inflammation, and further exposed to cannabinoid receptor agonists. In order to evaluate nerve density, tracheal segments were also examined by immunohistochemistry after in vitro treatments. The CB1 receptor agonists ACEA and ACPA inhibited the constant train EFS-induced contractions in both fresh and NGF-exposed tracheas, an effect that could be blocked by the CB1 receptor antagonist AM251. Culturing the tissues with NGF up-regulated the frequency-dependent EFS-contractions in isolated tracheas. This up-regulation could be inhibited by concomitant treatment with ACEA or ACPA. The treatment with NGF and/or ACEA did not affect the potency or the maximum response to carbachol. In histological sections, it was recognized that the enhanced effect induced by NGF was associated with an increase in nerve density, which, similarly, could be prevented by ACEA treatment. This study shows that stimulation of cannabinoid CB1 receptors modifies the increase of neuronal activity and density in NGF-induced airway inflammation and directly inhibits cholinergic contractions in the airways by a presynaptic mechanism. These findings indicate a protective role of CB1 receptors in airway inflammation.