RESUMO
Allergic asthma is a chronic inflammatory disease and despite the introduction of potent and effective drugs, the prevalence has increased substantially over the past few decades. The explanation that has attracted the most attention is the 'hygiene hypothesis', which suggests that the increase in allergic diseases is caused by a cleaner environment and fewer childhood infections. Indeed, certain mycobacterial strains can cause a shift from T-helper cell 2 (Th2) to Th1 immune responses, which may subsequently prevent the development of allergy in mice. Although the reconstitution of the balance between Th1 and Th2 is an attractive theory, it is unlikely to explain the whole story, as autoimmune diseases characterized by Th1 responses can also benefit from treatment with mycobacteria and their prevalence has also increased in parallel to allergies. Here we show that treatment of mice with SRP299, a killed Mycobacterium vaccae-suspension, gives rise to allergen-specific CD4+CD45RB(Lo) regulatory T cells, which confer protection against airway inflammation. This specific inhibition was mediated through interleukin-10 (IL-10) and transforming growth factor-beta (TGF-beta), as antibodies against IL-10 and TGF-beta completely reversed the inhibitory effect of CD4+CD45RB(Lo) T cells. Thus, regulatory T cells generated by mycobacteria treatment may have an essential role in restoring the balance of the immune system to prevent and treat allergic diseases.
Assuntos
Alérgenos/imunologia , Eosinofilia/imunologia , Mycobacterium/imunologia , Linfócitos T/imunologia , Transferência Adotiva , Animais , Líquido da Lavagem Broncoalveolar/imunologia , Linfócitos T CD4-Positivos/imunologia , Eosinofilia/microbiologia , Feminino , Humanos , Imunoglobulina G/imunologia , Interferon gama/análise , Interleucinas/análise , Ativação Linfocitária , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/imunologia , Baço/imunologia , Células Th1/imunologia , Células Th2/imunologia , Fator de Crescimento Transformador beta/análiseRESUMO
BACKGROUND: AVE9633 is a new immunoconjugate comprising a humanized monoclonal antibody, anti-CD33 antigen, linked through a disulfide bond to the maytansine derivative DM4, a cytotoxic agent and potent tubulin inhibitor. It is undergoing a phase I clinical trial. Chemoresistance to anti-mitotic agents has been shown to be related, in part, to overexpression of ABC proteins. The aim of the present study was to investigate the potential roles of P-gp, MRP1 and BCRP in cytotoxicity in AVE9633-induced acute myeloid leukaemia (AML). METHODS: This study used AML cell lines expressing different levels of P-gp, MRP1 or BCRP proteins and twenty-five samples from AML patients. Expression and functionality of the transporter protein were analyzed by flow cytometry. The cytotoxicity of the drug was evaluated by MTT and apoptosis assays. RESULTS: P-gp activity, but not MRP1 and BCRP, attenuated AVE9633 and DM4 cytotoxicity in myeloid cell lines. Zosuquidar, a potent specific P-gp inhibitor, restored the sensitivity of cells expressing P-gp to both AVE9633 and DM4. However, the data from AML patients show that 10/25 samples of AML cells (40%) were resistant to AVE9633 or DM4 (IC(50) > 500 nM), and this was not related to P-gp activity (p-Value: 0.7). Zosuquidar also failed to re-establish drug sensitivity. Furthermore, this resistance was not correlated with CD33 expression (p-Value: 0.6) in those cells. CONCLUSION: P-gp activity is not a crucial mechanism of chemoresistance to AVE9633. For patients whose resistance to conventional anthracycline AML regimens is related to ABC protein expression, a combination with AVE9633 could be beneficial. Other mechanisms such as microtubule alteration could play an important role in chemoresistance to AVE9633.
Assuntos
Membro 1 da Subfamília B de Cassetes de Ligação de ATP/metabolismo , Imunoconjugados/farmacologia , Leucemia Mieloide Aguda/tratamento farmacológico , Leucemia Mieloide Aguda/metabolismo , Maitansina/análogos & derivados , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP , Transportadores de Cassetes de Ligação de ATP/metabolismo , Anticorpos Monoclonais/farmacologia , Antígenos CD/biossíntese , Antígenos CD/imunologia , Antígenos de Diferenciação Mielomonocítica/biossíntese , Antígenos de Diferenciação Mielomonocítica/imunologia , Dibenzocicloeptenos/farmacologia , Resistencia a Medicamentos Antineoplásicos , Células HL-60 , Humanos , Imunoconjugados/farmacocinética , Células K562 , Maitansina/farmacocinética , Proteínas Associadas à Resistência a Múltiplos Medicamentos/metabolismo , Proteínas de Neoplasias/metabolismo , Quinolinas/farmacologia , Lectina 3 Semelhante a Ig de Ligação ao Ácido SiálicoRESUMO
The family of Toll-like receptors (TLRs) is receiving considerable attention as potential regulators and controllers of the immune response through their ability to recognize pathogen-associated molecular patterns. The discovery that endogenous ligands, as well as microbial components, are recognized by TLRs, and that small-molecular-mass synthetic compounds activate TLRs, raised interest in these receptors as potential targets for the development of new therapies for multiple diseases. In this review, we discuss the current and future use of TLR agonists or antagonists in chronic inflammatory diseases and highlight potential problems that are associated with such approaches.
Assuntos
Proteínas de Drosophila , Sistemas de Liberação de Medicamentos/métodos , Inflamação/tratamento farmacológico , Glicoproteínas de Membrana/agonistas , Glicoproteínas de Membrana/antagonistas & inibidores , Receptores de Superfície Celular/agonistas , Receptores de Superfície Celular/antagonistas & inibidores , Animais , Humanos , Inflamação/imunologia , Inflamação/metabolismo , Glicoproteínas de Membrana/fisiologia , Receptores de Superfície Celular/fisiologia , Receptores Toll-LikeRESUMO
We examined nuclear factor kappaB activation, release of inflammatory mediators and cellular infiltration in acute cigarette smoke inflammation models. One hour after exposure to one puff of cigarette smoke, alveolar macrophages from bronchoalveolar lavage (BAL) fluid of C57BL/6J mice showed an increased activity of nuclear factor kappaB-DNA binding but similar numbers as compared to that of BAL fluid from mice exposed to ambient air. Exposure to 1 cigarette/day for 1, 4 or 7 days led to an increase in interleukin-1beta and monocyte chemoattractant protein-1 levels and to a progressive influx of nuclear factor kappaB-activated alveolar macrophages into the BAL fluid and lung tissue. Exposure to 2 cigarettes/day for 7 days led to a significant increase in interleukin-1beta levels accompanied by a massive alveolar macrophage influx into the BAL fluid. Tumor necrosis factor-alpha levels and subsequent neutrophil influx were only detected after exposure to 4 or 8 cigarettes/day for 7 days. Treatment of mice with an antibody anti-interleukin-1beta during cigarette smoke exposure for 7 days significantly reduced both interleukin-1beta levels and alveolar macrophage influx. These data show that a single exposure to cigarette smoke rapidly activates alveolar macrophages, inducing the production of interleukin-1beta, which may play an important role in triggering chronic cigarette smoke-mediated lung inflammation.
Assuntos
Interleucina-1/metabolismo , Pulmão/efeitos dos fármacos , Nicotiana/toxicidade , Análise de Variância , Animais , Anticorpos/imunologia , Anticorpos/farmacologia , Líquido da Lavagem Broncoalveolar/química , Líquido da Lavagem Broncoalveolar/citologia , Quimiocina CCL2/metabolismo , Ensaio de Imunoadsorção Enzimática , Inflamação/induzido quimicamente , Inflamação/metabolismo , Interleucina-1/antagonistas & inibidores , Interleucina-1/imunologia , Pulmão/metabolismo , Pulmão/patologia , Macrófagos Alveolares/efeitos dos fármacos , Macrófagos Alveolares/metabolismo , Macrófagos Alveolares/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , NF-kappa B/metabolismo , Ligação Proteica/efeitos dos fármacos , Fumaça , Fator de Necrose Tumoral alfa/metabolismoRESUMO
This Keystone meeting entitled 'Rethinking the Pathogenesis of Asthma' was held at Santa Fe, USA. Numerous topics were discussed, including the pathogenesis of asthma, from the perspective of better understanding the contribution of the immune system and the impact of environmental factors on the development of allergic diseases, and current research and new trends in immunotherapy to prevent and treat asthma. Of particular relevance to novel drug development was a session entitled 'Novel therapeutic approaches' co-chaired by Achsah D Keegan (American Red Cross, USA) and Arthur M Krieg (Coley Pharmaceutical Group, USA), in which the results of several clinical trial studies on potential new asthma therapies were presented.
RESUMO
Milk Fat Globule--EGF--factor VIII (MFGE8), also called lactadherin, is a secreted protein, which binds extracellularly to phosphatidylserine and to αvß3 and αvß5 integrins. On human and mouse cells expressing these integrins, such as endothelial cells, phagocytes and some tumors, MFGE8/lactadherin has been shown to promote survival, epithelial to mesenchymal transition and phagocytosis. A protumoral function of MFGE8 has consequently been documented for a few types of human cancers, including melanoma, a subtype of breast cancers, and bladder carcinoma. Inhibiting the functions of MFGE8 could thus represent a new type of therapy for human cancers. Here, we show by immunohistochemistry on a collection of human ovarian cancers that MFGE8 is overexpressed in 45% of these tumors, and we confirm that it is specifically overexpressed in the triple-negative subtype of human breast cancers. We have established new in vitro assays to measure the effect of MFGE8 on survival, adhesion and migration of human ovarian and triple-negative breast cancer cell lines. Using these assays, we could identify new MFGE8-specific monoclonal antibodies, which efficiently blocked these three tumor-promoting effects of MFGE8. Our results suggest future use of MFGE8-blocking antibodies as new anti-cancer therapeutics in subgroups of ovarian carcinoma, and triple-negative breast carcinoma patients.
Assuntos
Anticorpos Bloqueadores/farmacologia , Antígenos de Superfície/imunologia , Movimento Celular/efeitos dos fármacos , Proteínas do Leite/imunologia , Terapia de Alvo Molecular , Neoplasias Ovarianas/tratamento farmacológico , Neoplasias Ovarianas/patologia , Animais , Antígenos de Superfície/metabolismo , Bioensaio , Biópsia , Adesão Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Feminino , Humanos , Camundongos , Proteínas do Leite/metabolismo , Neoplasias de Mama Triplo Negativas/metabolismo , Neoplasias de Mama Triplo Negativas/patologiaRESUMO
PURPOSE: To investigate the activity of SAR3419, a novel humanized anti-CD19 antibody (huB4), conjugated to a cytotoxic maytansine derivative N(2)'-deacetyl-N(2)'-(4-mercapto-4-methyl-1-oxopentyl) maytansine, in preclinical xenograft models for non-Hodgkin's lymphoma. EXPERIMENTAL DESIGN: Antitumor activity of SAR3419 was assessed as a single agent and in comparison with conventional therapies using a subcutaneous model for diffuse large B-cell lymphoma (WSU-DLCL2) and a systemic model for follicular small cleaved cell lymphoma (WSU-FSCCL) in mice with severe combined immune deficiency. RESULTS: Our results showed that in these chemotherapy-resistant models, SAR3419 was more effective than CHOP (cyclophosphamide-Adriamycin-vincristine-prednisone) regimen or rituximab. Only treatment with SAR3419 led to survival of the whole group of animals to the end of the experiment (150-155 days) in both models. Higher doses of SAR3419 (15 and 30 mg/kg) were more effective than lower dose of 7.5 mg/kg. The immunoconjugation was necessary because neither huB4 nor DM4 alone had significant activity. Treatment with rituximab resulted in antitumor activity in both models comparable with the low dose of SAR3419. Cyclophosphamide-Adriamycin-vincristine-prednisone alone showed modest activity in both models. Necropsy and tissue staining in the WSU-FSCCL systemic model revealed that all deaths featured leptomeningeal lymphoma in the control and treated groups. Interestingly, some of the animals that survived to the end of the experiment and seemed healthy at time of euthanasia did show microscopic evidence of lymphoma. CONCLUSIONS: Overall, SAR3419 is a very active immunotoxin in preclinical models for human B-cell lymphoma and holds promise as a novel and well-tolerated therapy in B-cell non-Hodgkin's lymphoma.
Assuntos
Anticorpos Monoclonais/uso terapêutico , Antineoplásicos Fitogênicos/uso terapêutico , Imunoconjugados/uso terapêutico , Linfoma Folicular/tratamento farmacológico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Maitansina/análogos & derivados , Maitansina/uso terapêutico , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais Murinos , Antígenos CD19/metabolismo , Antineoplásicos Fitogênicos/química , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linhagem Celular Tumoral , Ciclofosfamida/uso terapêutico , Doxorrubicina/uso terapêutico , Humanos , Fatores Imunológicos/uso terapêutico , Linfoma Folicular/patologia , Linfoma Difuso de Grandes Células B/patologia , Camundongos , Camundongos SCID , Prednisona/uso terapêutico , Rituximab , Vincristina/uso terapêutico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
The sphingosine 1-phosphate receptor agonist FTY720 is a novel immunomodulator that sequesters lymphocytes in secondary lymphoid organs and thereby prevents their migration to sites of inflammation. However, there is currently no information available on whether this drug affects Th1 or Th2 cell-mediated lung-inflammatory responses. The effect of FTY720 was therefore investigated in a murine airway inflammation model using OVA-specific, in vitro differentiated, and adoptively transferred Th1 and Th2 cells. Both Th1 and Th2 cells express a similar pattern of FTY720-targeted sphingosine 1-phosphate receptors. The OVA-induced Th1-mediated airway inflammation characterized by increased numbers of lymphocytes and neutrophils in bronchoalveolar lavage fluid was significantly inhibited by oral FTY720 treatment. Similarly, FTY720 suppressed the Th2 cell-induced bronchoalveolar lavage fluid eosinophilia and the infiltration of T lymphocytes and eosinophils into the bronchial tissue. Moreover, the Ag-induced bronchial hyperresponsiveness to inhaled metacholine was almost completely blocked. The inhibitory effect of FTY720 on airway inflammation, induction of bronchial hyperresponsiveness, and goblet cell hyperplasia could be confirmed in an actively Ag-sensitized murine asthma model, clearly indicating that Th2 cell-driven allergic diseases such as asthma could benefit from such treatment.
Assuntos
Anti-Inflamatórios não Esteroides/administração & dosagem , Imunossupressores/administração & dosagem , Pulmão/patologia , Propilenoglicóis/administração & dosagem , Receptores Acoplados a Proteínas G/agonistas , Esfingosina/metabolismo , Células Th1/transplante , Células Th2/transplante , Animais , Asma/tratamento farmacológico , Asma/imunologia , Asma/patologia , Hiper-Reatividade Brônquica/imunologia , Hiper-Reatividade Brônquica/prevenção & controle , Efeito Espectador/efeitos dos fármacos , Efeito Espectador/imunologia , Movimento Celular/efeitos dos fármacos , Movimento Celular/imunologia , Modelos Animais de Doenças , Epitopos de Linfócito T/imunologia , Cloridrato de Fingolimode , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/prevenção & controle , Pulmão/efeitos dos fármacos , Pulmão/imunologia , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Receptores Acoplados a Proteínas G/biossíntese , Receptores de Lisofosfolipídeos , Células Th1/efeitos dos fármacos , Células Th1/metabolismo , Células Th2/efeitos dos fármacos , Células Th2/metabolismoRESUMO
BACKGROUND: Cytokines play an integral role in the coordination and persistence of allergic inflammatory processes and therefore represent prime targets for novel therapies in diseases such as asthma. Multiple attempts to generate low-molecular-weight cytokine inhibitors have failed, and the main attention has focused on the development of biological agents such as neutralizing antibodies. The present work describes a simple and effective method to induce the production of therapeutic anti-cytokine autoantibodies by active immunization against a modified endogenous cytokine. METHODS: Balb/c mice were subcutaneously injected with AutoVac TNF106, a recombinant murine TNF-alpha molecule containing a foreign immunogenic T helper epitope, and the induction of neutralizing anti-TNF-alpha autoantibodies was analysed. These mice were then sensitized with ovalbumin (OVA), and the effect of neutralizing anti-TNF-alpha autoantibodies on the allergen-induced airway inflammation was analysed. RESULTS: AutoVac TNF106-immunized mice developed high titres of neutralizing anti-TNF-alpha autoantibodies, which were maintained for at least 4 weeks after the last booster injection. Mice vaccinated with AutoVac TNF106 and further immunized against OVA showed diminished TNF-alpha levels in the bronchoalveolar lavage (BAL) fluid after OVA challenge. Moreover, pretreatment with AutoVac TNF106 resulted in significantly reduced numbers of eosinophils and neutrophils in BAL fluid in response to single or multiple allergen exposure. CONCLUSION: The induction of anti-TNF-alpha autoantibody production by the AutoVac TNF106 technology not only confirmed the role of TNF-alpha in the induction of allergic inflammation but also offers a novel approach to block the activity of cytokines in order to treat allergic inflammatory conditions.
Assuntos
Autoanticorpos/biossíntese , Hiper-Reatividade Brônquica/imunologia , Hiper-Reatividade Brônquica/terapia , Imunoterapia/métodos , Fator de Necrose Tumoral alfa/imunologia , Animais , Autoanticorpos/sangue , Autoanticorpos/imunologia , Testes de Provocação Brônquica , Líquido da Lavagem Broncoalveolar/citologia , Broncoconstritores/farmacologia , Contagem de Células , Citocinas/imunologia , Citocinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Feminino , Imunização , Imunoglobulina E/imunologia , Imunoglobulina E/metabolismo , Cloreto de Metacolina/farmacologia , Camundongos , Camundongos Endogâmicos BALB C , Ovalbumina/imunologia , Eosinofilia Pulmonar/imunologia , Eosinofilia Pulmonar/terapia , Proteínas Recombinantes/imunologia , Proteínas Recombinantes/farmacologia , Fator de Necrose Tumoral alfa/farmacologiaRESUMO
This report examines the effect of heat-killed Mycobacterium vaccae in a mouse model of allergic pulmonary inflammation. The s.c. administration of M. vaccae 3 wk before the immunization significantly reduced Ag-induced airway hyperreactivity and the increase in the numbers of eosinophils observed in the bronchoalveolar lavage fluid, blood, and bone marrow, even though no detectable changes in either cytokine (IL-4, IL-13, IL-5, and IFN-gamma) or total IgE levels were observed. Furthermore, transfer of splenocytes from OVA-immunized and M. vaccae-treated mice into recipient, OVA-immunized mice significantly reduced the allergen-induced eosinophilia by an IFN-gamma-independent mechanism, clearly indicating that the mechanism by which M. vaccae induces its inhibitory effect is not due to a redirection from a predominantly Th2 to a Th1-dominated immune response. The protective effect of M. vaccae on the allergen-induced eosinophilia lasted for at least 12 wk after its administration, and the treatment was also effective in presensitized mice. Moreover, the allergen specificity of the inhibitory effect could be demonstrated using a double-immunization protocol, where M. vaccae treatment before OVA immunization had no effect on the eosinophilic inflammation induced by later immunization and challenge with cockroach extract Ag. Taken together, these results clearly demonstrate that M. vaccae is effective in blocking allergic inflammation by a mechanism independent of IFN-gamma, induces long term and Ag-specific protection, and therefore has both prophylactic and therapeutic potential for the treatment of allergic diseases.
Assuntos
Antígenos/imunologia , Vacinas Bacterianas/imunologia , Hiper-Reatividade Brônquica/prevenção & controle , Hipersensibilidade/prevenção & controle , Inflamação/prevenção & controle , Transferência Adotiva , Animais , Quimiocinas/biossíntese , Citocinas/biossíntese , Eosinofilia/prevenção & controle , Eosinófilos/fisiologia , Feminino , Imunização , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Imunoglobulina G/classificação , Camundongos , Camundongos Endogâmicos BALB C , Oligodesoxirribonucleotídeos/farmacologia , Ovalbumina/imunologia , Vacinas de Produtos Inativados/imunologiaRESUMO
Over the last few years, we examined the anti-allergic properties of interleukin (IL)-10 in different models of inflammation in the mouse, as well as against IgE-dependent activation of mouse bone marrow-derived mast cells (BMMC). We showed that IL-10, concurrently administered with ovalbumin, inhibited inflammatory cell accumulation in the airways and in the peritoneal cavity of sensitized mice, as well as the accompanying cytokine release. IL-10 also blocked antigen-induced cytokine generation by IgE-stimulated BMMC. Together, these results identify a novel biological property of IL-10, as a cytokine with potent anti-allergic activities.