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1.
J Immunol ; 194(12): 5895-902, 2015 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-25941327

RESUMO

The development of vaccines inducing efficient CD8(+) T cell responses is the focus of intense research. Dendritic cells (DCs) expressing the XCR1 chemokine receptor, also known as CD103(+) or CD8α(+) DCs, excel in the presentation of extracellular Ags to CD8(+) T cells. Because of its high numbers of DCs, including XCR1(+) DCs, the skin dermis is an attractive site for vaccine administration. By creating laser-generated micropores through the epidermis, we targeted a model protein Ag fused to XCL1, the ligand of XCR1, to dermal XCR1(+) DCs and induced Ag-specific CD8(+) and CD4(+) T cell responses. Efficient immunization required the emigration of XCR1(+) dermal DCs to draining lymph nodes and occurred irrespective of TLR signaling. Moreover, a single intradermal immunization protected mice against melanoma tumor growth in prophylactic and therapeutic settings, in the absence of exogenous adjuvant. The mild inflammatory milieu created in the dermis by skin laser microporation itself most likely favored the development of potent T cell responses in the absence of exogenous adjuvants. The existence of functionally equivalent XCR1(+) dermal DCs in humans should permit the translation of laser-assisted intradermal delivery of a tumor-specific vaccine targeting XCR1(+) DCs to human cancer immunotherapy. Moreover, considering that the use of adjuvants in vaccines is often associated with safety issues, the possibility of inducing protective responses against melanoma tumor growth independently of the administration of exogenous adjuvants should facilitate the development of safer vaccines.


Assuntos
Vacinas Anticâncer/imunologia , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Neoplasias/imunologia , Receptores de Quimiocinas/metabolismo , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Vacinas Anticâncer/administração & dosagem , Quimiocinas C/genética , Quimiocinas C/metabolismo , Modelos Animais de Doenças , Injeções Intradérmicas , Melanoma Experimental , Camundongos , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/metabolismo , Neoplasias/patologia , Neoplasias/terapia , Ovalbumina/genética , Ovalbumina/imunologia , Ligação Proteica , Receptores de Quimiocinas/genética , Subpopulações de Linfócitos T/imunologia , Carga Tumoral/imunologia
2.
J Allergy Clin Immunol ; 138(4): 984-1010, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27577879

RESUMO

There have been extensive developments on cellular and molecular mechanisms of immune regulation in allergy, asthma, autoimmune diseases, tumor development, organ transplantation, and chronic infections during the last few years. Better understanding the functions, reciprocal regulation, and counterbalance of subsets of immune and inflammatory cells that interact through interleukins, interferons, TNF-α, and TGF-ß offer opportunities for immune interventions and novel treatment modalities in the era of development of biological immune response modifiers particularly targeting these molecules or their receptors. More than 60 cytokines have been designated as interleukins since the initial discoveries of monocyte and lymphocyte interleukins (called IL-1 and IL-2, respectively). Studies of transgenic or gene-deficient mice with altered expression of these cytokines or their receptors and analyses of mutations and polymorphisms in human genes that encode these products have provided essential information about their functions. Here we review recent developments on IL-1 to IL-38, TNF-α, TGF-ß, and interferons. We highlight recent advances during the last few years in this area and extensively discuss their cellular sources, targets, receptors, signaling pathways, and roles in immune regulation in patients with allergy and asthma and other inflammatory diseases.


Assuntos
Doenças do Sistema Imunitário , Interferons/fisiologia , Interleucinas/fisiologia , Linfócitos T Reguladores/imunologia , Fator de Crescimento Transformador beta/fisiologia , Fator de Necrose Tumoral alfa/fisiologia , Animais , Humanos
3.
Am J Respir Crit Care Med ; 187(6): 621-9, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23306544

RESUMO

RATIONALE: Cystic fibrosis (CF) is characterized by progressive pulmonary inflammation that is infection-triggered. Pseudomonas aeruginosa represents a risk factor for deterioration of lung function and reduced life expectancy. OBJECTIVES: To assess T-cell cytokine/chemokine production in clinically stable children with CF and evaluate the association between T-cell subtypes and susceptibility for infection with P. aeruginosa. METHODS: T-cell cytokine/chemokine profiles were measured in bronchoalveolar lavage fluid (BALF) from children with CF (n = 57; 6.1 ± 5.9 yr) and non-CF control subjects (n = 18; 5.9 ± 4.3 yr). Memory responses to Aspergillus fumigatus and P. aeruginosa were monitored. High-resolution computed tomography-based Helbich score was assessed. In a prospective observational trial the association between BALF cytokine/chemokine profiles and subsequent infection with P. aeruginosa was studied. MEASUREMENTS AND MAIN RESULTS: Th1- (INF-γ), Th2- (IL-5, IL-13), Th17- (IL-17A), and Th17-related cytokines (IL-1ß, IL-6) were significantly up-regulated in airways of patients with CF. IL-17A, IL-13, and IL-5 were significantly higher in BALF of symptomatic as compared with clinically asymptomatic patients with CF. IL-17A and IL-5 correlated with the percentage of neutrophils in BALF (r = 0.41, P < 0.05 and r = 0.46, P < 0.05, respectively). Th17- (IL-17A, IL-6, IL-1ß, IL-8) and Th2-associated cytokines and chemokines (IL-5, IL-13, TARC/CCL17), but not IFN-γ levels, significantly correlated with high-resolution computed tomography changes (Helbich score; P < 0.05). P. aeruginosa- and A. fumigatus-specific T cells from patients with CF displayed significantly higher IL-5 and IL-17A mRNA expression. IL-17A and TARC/CCL17 were significantly augmented in patients that developed P. aeruginosa infection within 24 months. CONCLUSIONS: We propose a role for Th17 and Th2 T cells in chronic inflammation in lungs of patients with CF. High concentrations of these cytokines/chemokines in CF airways precede infection with P. aeruginosa.


Assuntos
Fibrose Cística/metabolismo , Citocinas/metabolismo , Infecções por Pseudomonas/metabolismo , Pseudomonas aeruginosa , Células Th17/metabolismo , Células Th2/metabolismo , Adolescente , Líquido da Lavagem Broncoalveolar , Criança , Pré-Escolar , Feminino , Humanos , Interferon gama/metabolismo , Masculino , Prognóstico , Estudos Prospectivos
5.
J Allergy Clin Immunol ; 129(5): 1290-6, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22464647

RESUMO

BACKGROUND: Subcutaneous allergen-specific immunotherapy frequently causes allergic side effects and requires 30 to 80 injections over 3 to 5 years. OBJECTIVE: We sought to improve immunotherapy by using intralymphatic allergen administration (intralymphatic immunotherapy [ILIT]) and by targeting allergen to the MHC class II pathway. METHODS: Recombinant major cat dander allergen Fel d 1 was fused to a translocation sequence (TAT) and to part of the human invariant chain, generating a modular antigen transporter (MAT) vaccine (MAT-Fel d 1). In a randomized double-blind trial ILIT with MAT-Fel d 1 in alum was compared with ILIT with placebo (saline in alum) in allergic patients (ClinicalTrials.govNCT00718679). RESULTS: ILIT with MAT-Fel d 1 elicited no adverse events. After 3 placebo injections within 2 months, nasal tolerance increased less than 3-fold, whereas 3 intralymphatic injections with MAT-Fel d 1 increased nasal tolerance 74-fold (P < .001 vs placebo). ILIT with MAT-Fel d 1 stimulated regulatory T-cell responses (P = .026 vs placebo) and increased cat dander-specific IgG(4) levels by 5.66-fold (P = .003). The IgG(4) response positively correlated with IL-10 production (P < .001). CONCLUSION: In a first-in-human clinical study ILIT with MAT-Fel d 1 was safe and induced allergen tolerance after 3 injections.


Assuntos
Alérgenos/administração & dosagem , Dessensibilização Imunológica , Glicoproteínas/administração & dosagem , Hipersensibilidade/tratamento farmacológico , Linfócitos T Reguladores/efeitos dos fármacos , Adulto , Alérgenos/efeitos adversos , Alérgenos/genética , Alérgenos/metabolismo , Animais , Formação de Anticorpos/efeitos dos fármacos , Antígenos de Diferenciação de Linfócitos B/genética , Antígenos de Diferenciação de Linfócitos B/metabolismo , Gatos , Células Cultivadas , Feminino , Glicoproteínas/efeitos adversos , Glicoproteínas/genética , Antígenos de Histocompatibilidade Classe II/genética , Antígenos de Histocompatibilidade Classe II/metabolismo , Humanos , Hipersensibilidade/diagnóstico , Hipersensibilidade/imunologia , Hipersensibilidade/fisiopatologia , Imunoglobulina G/sangue , Injeções Intralinfáticas , Interleucina-10/metabolismo , Masculino , Pessoa de Meia-Idade , Fragmentos de Peptídeos/genética , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/genética , Testes Cutâneos , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Linfócitos T Reguladores/patologia , Adulto Jovem
6.
Eur J Immunol ; 41(4): 1058-69, 2011 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-21337543

RESUMO

HIV infection is characterized by sustained immune activation, which is reflected by activated T cells and, in particular, by increased levels of phosphorylated STAT proteins. Here, we hypothesized that T-cell activation in HIV infection is partially due to the inability of SOCS-1 and SOCS-3 to control the JAK/STAT pathway. We found higher levels of SOCS-1/3 mRNA levels in CD4(+) T cells of HIV-infected patients than in healthy controls. However, SOCS protein levels were lower, explaining the lack of attenuation of the JAK/STAT pathway. Infection of CD4(+) T cells alone did not activate STATs, while ex vivo infection of PBMC did, indicating that non-T cells critical for shaping the immune response, e.g. DC were responsible for the STAT-1 activation. Supernatants from ex vivo-infected PBMC transferred to CD4(+) T cells induced JAK/STAT activation, pointing to a central role of soluble factors. Notably, over-expression of SOCS-1/3 in CD4(+) T cells prevented JAK/STAT activation. Thus, HIV infection interferes with SOCS-1/3 expression driving immune activation. Sustained immune activation disrupts the lymphoid system and favors HIV replication since HIV preferentially infects activated cells. We speculate that regulating SOCS may be a potential way to counteract immune activation in HIV disease.


Assuntos
Infecções por HIV/imunologia , Proteínas Supressoras da Sinalização de Citocina/imunologia , Adulto , Células Cultivadas , Regulação da Expressão Gênica , Infecções por HIV/metabolismo , Humanos , Janus Quinases/metabolismo , Pessoa de Meia-Idade , RNA Mensageiro/genética , Fatores de Transcrição STAT/metabolismo , Transdução de Sinais , Proteína 1 Supressora da Sinalização de Citocina , Proteína 3 Supressora da Sinalização de Citocinas , Proteínas Supressoras da Sinalização de Citocina/genética , Linfócitos T/imunologia
7.
J Allergy Clin Immunol ; 128(1): 92-99.e4, 2011 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-21489611

RESUMO

BACKGROUND: IgE-mediated cross-reactivity between fungal antigens and human proteins has been described in patients with atopic dermatitis (AD), but it remains to be elucidated whether there is also cross-reactivity at the T-cell level. OBJECTIVE: We sought to explore cross-reactivity at the T-cell level between the fungal thioredoxin (Mala s 13) of the skin-colonizing yeast Malassezia sympodialis and its homologous human thioredoxin (hTrx). METHODS: T-cell lines (TCLs) were generated in the presence of rMala s 13 from the peripheral blood and from skin biopsy specimens of positive patch test reactions of patients with AD sensitized to Mala s 13 and hTrx. Patients with AD not sensitized to Malassezia species, healthy subjects, and patients with psoriasis served as control subjects. Mala s 13-specific T-cell clones (TCCs) were generated from TCLs. TCCs were characterized by antigen specificity, phenotype, and cytokine secretion pattern. Human keratinocytes were stimulated with IFN-γ, TNF-α, and IL-4, and the release of hTrx was determined by means of ELISA. RESULTS: Mala s 13-specific TCLs and TCCs from the blood and skin of patients with AD sensitized to Mala s 13 and hTrx were fully cross-reactive with hTrx. Mala s 13- and hTrx-specific TCCs could not be generated from control subjects. The majority of cross-reactive TCCs were CD4(+) and coexpressed cutaneous lymphocyte antigen. In addition to T(H)1 and T(H)2 TCCs, we could also identify TCCs secreting IL-17 and IL-22. After stimulation with IFN-γ and TNF-α, keratinocytes released substantial amounts of thioredoxin. CONCLUSION: In patients with AD sensitized to Malassezia species, cross-reactivity at the T-cell level to Mala s 13 and the homologous hTrx is detectable. hTrx autoreactive skin-homing T cells might be relevant for cutaneous inflammation in patients with AD.


Assuntos
Autoimunidade/imunologia , Dermatite Atópica/imunologia , Malassezia/imunologia , Linfócitos T/imunologia , Tiorredoxinas/imunologia , Adulto , Idoso , Antígenos de Fungos/imunologia , Autoantígenos/imunologia , Reações Cruzadas , Dermatite Atópica/microbiologia , Dermatomicoses/imunologia , Ensaio de Imunoadsorção Enzimática , Humanos , Adulto Jovem
8.
J Allergy Clin Immunol ; 127(3): 701-21.e1-70, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21377040

RESUMO

Advancing our understanding of mechanisms of immune regulation in allergy, asthma, autoimmune diseases, tumor development, organ transplantation, and chronic infections could lead to effective and targeted therapies. Subsets of immune and inflammatory cells interact via ILs and IFNs; reciprocal regulation and counter balance among T(h) and regulatory T cells, as well as subsets of B cells, offer opportunities for immune interventions. Here, we review current knowledge about ILs 1 to 37 and IFN-γ. Our understanding of the effects of ILs has greatly increased since the discoveries of monocyte IL (called IL-1) and lymphocyte IL (called IL-2); more than 40 cytokines are now designated as ILs. Studies of transgenic or knockout mice with altered expression of these cytokines or their receptors and analyses of mutations and polymorphisms in human genes that encode these products have provided important information about IL and IFN functions. We discuss their signaling pathways, cellular sources, targets, roles in immune regulation and cellular networks, roles in allergy and asthma, and roles in defense against infections.


Assuntos
Doenças do Sistema Imunitário , Interferon gama/fisiologia , Interleucinas/imunologia , Receptores de Interferon/imunologia , Receptores de Interleucina/imunologia , Animais , Humanos , Doenças do Sistema Imunitário/etiologia , Doenças do Sistema Imunitário/imunologia , Interleucinas/classificação , Camundongos
9.
Eur J Immunol ; 40(11): 3161-72, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20865787

RESUMO

HAX1 was originally described as HS1-associated protein with a suggested function in receptor-mediated apoptotic and proliferative responses of lymphoid cells. Recent publications refer to a complex and multifunctional role of this protein. To investigate the in vivo function of HAX1 (HS1-associated protein X1) in B cells, we generated a Hax1-deficient mouse strain. Targeted deletion of Hax1 resulted in premature death around the age of 12 wk accompanied by a severe reduction of lymphocytes in spleen, thymus and bone marrow. In the bone marrow, all B-cell populations were lost comparably. In the spleen, B220(+) cells were reduced by almost 70%. However, as investigated by adoptive transfer experiments, this impairment is not exclusively B-cell intrinsic and we hypothesize that a HAX1-deficient environment cannot sufficiently provide the essential factors for proper lymphocyte development, trafficking and survival. Hax1(-/-) B cells show a significantly reduced expression of CXCR4, which might have an influence on the observed defects in B-cell development.


Assuntos
Linfócitos B/imunologia , Movimento Celular/imunologia , Linfopoese/imunologia , Proteínas/imunologia , Animais , Linfócitos B/metabolismo , Medula Óssea/imunologia , Medula Óssea/metabolismo , Movimento Celular/genética , Sobrevivência Celular/genética , Sobrevivência Celular/imunologia , Regulação da Expressão Gênica/genética , Regulação da Expressão Gênica/imunologia , Peptídeos e Proteínas de Sinalização Intracelular , Antígenos Comuns de Leucócito/genética , Antígenos Comuns de Leucócito/imunologia , Antígenos Comuns de Leucócito/metabolismo , Linfopoese/genética , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Proteínas/genética , Proteínas/metabolismo , Receptores CXCR4/biossíntese , Receptores CXCR4/genética , Receptores CXCR4/imunologia , Baço/imunologia , Baço/metabolismo , Timo/imunologia , Timo/metabolismo
10.
Proc Natl Acad Sci U S A ; 105(46): 17908-12, 2008 Nov 18.
Artigo em Inglês | MEDLINE | ID: mdl-19001265

RESUMO

The only causative treatment for IgE-mediated allergies is allergen-specific immunotherapy. However, fewer than 5% of allergy patients receive immunotherapy because of its long duration and risk of allergic side effects. We aimed at enhancing s.c. immunotherapy by direct administration of allergen into s.c. lymph nodes. The objective was to evaluate safety and efficacy compared with conventional s.c. immunotherapy. In a monocentric open-label trial, 165 patients with grass pollen-induced rhinoconjunctivitis were randomized to receive either 54 s.c. injections with pollen extract over 3 years [cumulative allergen dose 4,031,540 standardized quality units (SQ-U)] or 3 intralymphatic injections over 2 months (cumulative allergen dose 3,000 SQ-U). Patients were evaluated after 4 months, 1 year, and 3 years by nasal provocation, skin prick testing, IgE measurements, and symptom scores. Three low-dose intralymphatic allergen administrations increased tolerance to nasal provocation with pollen already within 4 months (P < 0.001). Tolerance was long lasting and equivalent to that achievable after standard s.c. immunotherapy (P = 0.291 after 3 years). Intralymphatic immunotherapy ameliorated hay fever symptoms (P < 0.001), reduced skin prick test reactivity (P < 0.001), decreased specific serum IgE (P < 0.001), caused fewer adverse events than s.c. immunotherapy (P = 0.001), enhanced compliance (P < 0.001), and was less painful than venous puncture (P = 0.018). In conclusion, intralymphatic allergen administration enhanced safety and efficacy of immunotherapy and reduced treatment time from 3 years to 8 weeks.


Assuntos
Alérgenos/administração & dosagem , Alérgenos/uso terapêutico , Dessensibilização Imunológica , Adolescente , Adulto , Idoso , Alérgenos/efeitos adversos , Antialérgicos/uso terapêutico , Dessensibilização Imunológica/efeitos adversos , Feminino , Humanos , Hipersensibilidade/tratamento farmacológico , Tolerância Imunológica/imunologia , Imunoglobulina E/sangue , Injeções Intralinfáticas/efeitos adversos , Injeções Subcutâneas/efeitos adversos , Masculino , Pessoa de Meia-Idade , Dor/imunologia , Testes Cutâneos , Fatores de Tempo , Resultado do Tratamento
12.
J Exp Med ; 199(11): 1567-75, 2004 Jun 07.
Artigo em Inglês | MEDLINE | ID: mdl-15173208

RESUMO

The mechanisms by which immune responses to nonpathogenic environmental antigens lead to either allergy or nonharmful immunity are unknown. Single allergen-specific T cells constitute a very small fraction of the whole CD4+ T cell repertoire and can be isolated from the peripheral blood of humans according to their cytokine profile. Freshly purified interferon-gamma-, interleukin (IL)-4-, and IL-10-producing allergen-specific CD4+ T cells display characteristics of T helper cell (Th)1-, Th2-, and T regulatory (Tr)1-like cells, respectively. Tr1 cells consistently represent the dominant subset specific for common environmental allergens in healthy individuals; in contrast, there is a high frequency of allergen-specific IL-4-secreting T cells in allergic individuals. Tr1 cells use multiple suppressive mechanisms, IL-10 and TGF-beta as secreted cytokines, and cytotoxic T lymphocyte antigen 4 and programmed death 1 as surface molecules. Healthy and allergic individuals exhibit all three allergen-specific subsets in different proportions, indicating that a change in the dominant subset may lead to allergy development or recovery. Accordingly, blocking the suppressor activity of Tr1 cells or increasing Th2 cell frequency enhances allergen-specific Th2 cell activation ex vivo. These results indicate that the balance between allergen-specific Tr1 cells and Th2 cells may be decisive in the development of allergy.


Assuntos
Alérgenos/imunologia , Hipersensibilidade/imunologia , Linfócitos T/imunologia , Células Th2/imunologia , Adulto , Antígenos CD , Antígenos de Diferenciação/fisiologia , Antígeno CTLA-4 , Humanos , Hipersensibilidade/etiologia , Interferon gama/biossíntese , Interleucina-10/biossíntese , Interleucina-4/biossíntese , Fator de Crescimento Transformador beta/biossíntese
13.
PLoS Biol ; 5(12): e329, 2007 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18162042

RESUMO

Transcription factors act in concert to induce lineage commitment towards Th1, Th2, or T regulatory (Treg) cells, and their counter-regulatory mechanisms were shown to be critical for polarization between Th1 and Th2 phenotypes. FOXP3 is an essential transcription factor for natural, thymus-derived (nTreg) and inducible Treg (iTreg) commitment; however, the mechanisms regulating its expression are as yet unknown. We describe a mechanism controlling iTreg polarization, which is overruled by the Th2 differentiation pathway. We demonstrated that interleukin 4 (IL-4) present at the time of T cell priming inhibits FOXP3. This inhibitory mechanism was also confirmed in Th2 cells and in T cells of transgenic mice overexpressing GATA-3 in T cells, which are shown to be deficient in transforming growth factor (TGF)-beta-mediated FOXP3 induction. This inhibition is mediated by direct binding of GATA3 to the FOXP3 promoter, which represses its transactivation process. Therefore, this study provides a new understanding of tolerance development, controlled by a type 2 immune response. IL-4 treatment in mice reduces iTreg cell frequency, highlighting that therapeutic approaches that target IL-4 or GATA3 might provide new preventive strategies facilitating tolerance induction particularly in Th2-mediated diseases, such as allergy.


Assuntos
Fatores de Transcrição Forkhead/metabolismo , Fator de Transcrição GATA3/metabolismo , Linfócitos T Reguladores/metabolismo , Células Th2/imunologia , Células Th2/metabolismo , Fator de Crescimento Transformador beta1/farmacologia , Animais , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/imunologia , Células Cultivadas , Fatores de Transcrição Forkhead/genética , Regulação da Expressão Gênica , Humanos , Interleucina-4/biossíntese , Interleucina-4/farmacologia , Cinética , Camundongos , Regiões Promotoras Genéticas/genética , Linfócitos T Reguladores/química , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/imunologia , Células Th2/efeitos dos fármacos
14.
J Allergy Clin Immunol ; 124(2): 278-85, 285.e1-7, 2009 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-19541355

RESUMO

BACKGROUND: Atopic eczema (AE) is the most common chronic inflammatory skin disease. Recent data demonstrate the presence of autoreactive serum IgE antibodies correlating with the severity of the disease. OBJECTIVE: Although several IgE-binding self-antigens have been reported, the whole repertoire of IgE-binding self-antigens is unknown. We aimed to estimate the repertoire size of autoreactive proteins related to AE and clone, produce, and characterize humoral and T-cell responses against novel self-antigens. METHODS: Phage surface-displayed human cDNA libraries were enriched for clones binding to serum IgE from patients with AE and screened by using high-throughput technology. Selected clones were used to produce the encoded proteins, to test their IgE-binding ability in Western blots and ELISAs, and their ability to induce mediator release from basophils of sensitized individuals. RESULTS: One hundred forty sequences encoding potential IgE-binding self-antigens associated with AE were identified. Sixteen sequences encoded already described self-antigens. Three new sequences showed homology with environmental allergens, 86 encoded known human proteins, 7 predicted proteins, and 28 showed sequence identity with genomic contigs. Immunoblotting and ELISA experiments demonstrated the presence of IgE antibodies in sera from patients with AE to 5 selected recombinant self-antigens and their ability to induce mediator release from basophils of patients with AE who have self-antigen-specific IgE antibodies. CONCLUSION: These data demonstrate a broad spectrum of at least 140 IgE-binding self-antigens associated with AE. By binding IgE antibodies or activating specific T cells, they might promote, perpetuate, or both existing skin inflammation.


Assuntos
Reações Antígeno-Anticorpo , Autoantígenos/imunologia , Basófilos/imunologia , Dermatite Atópica/imunologia , Imunoglobulina E/imunologia , Adulto , Dermatite Atópica/sangue , Feminino , Biblioteca Gênica , Humanos , Imunoglobulina E/sangue , Imunoglobulina G/sangue , Masculino , Proteínas Recombinantes/imunologia
15.
Curr Opin Immunol ; 18(6): 761-8, 2006 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-17010585

RESUMO

Advances in genetic engineering and biotechnology, in parallel to increased understanding of disease processes and mechanisms of protective immunity, have facilitated the development of novel rational vaccination concepts for allergy. The spectrum ranges from utilizing recombinant proteins, peptides, new adjuvants, immunomodulatory therapy and DNA vaccines, to use of new application routes for both prophylaxis and treatment of allergic disease. New therapeutic concepts based on patient-tailored immunotherapy using recombinant allergens, anti-IgE and sublingual immunotherapies are slowly moving from the bench to the clinics. The additive value of new treatments above existing therapies must be, however, focused on the improvement of efficacy for long-term cure and increased patient compliance to warrant a broad applicability that has to compete with the symptomatic control of allergic and asthmatic diseases of currently available drugs.


Assuntos
Adjuvantes Imunológicos/uso terapêutico , Hipersensibilidade/prevenção & controle , Imunoterapia/métodos , Vacinas/imunologia , Alérgenos/imunologia , Animais , Humanos , Vacinas/química , Vacinas Sintéticas/química , Vacinas Sintéticas/imunologia
16.
Int Arch Allergy Immunol ; 150(1): 59-65, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19339803

RESUMO

BACKGROUND: IgE-mediated allergy can be treated by subcutaneous allergen-specific immunotherapy (SIT). However, the percentage of allergic patients undergoing SIT is low, mainly due to the long duration of the therapy and the risk of severe systemic allergic reactions associated with the allergen administration. To improve the safety and attractiveness of SIT for patients, alternative routes of allergen administration are being explored, such as sub-lingual or oral administration. METHODS: The present study evaluated direct intralymphatic allergen administration as a means to enhance SIT with bee venom and cat fur allergens in mice. Allergen-specific antibody and T-cell responses were analysed by ELISA and flow cytometry. The therapeutic potential of intralymphatic immunisation in sensitised mice was analysed using an anaphylaxis model. RESULTS: Direct injection of the major bee venom allergen phospholipase A(2) or the major cat fur allergen Fel d 1 into inguinal lymph nodes enhanced allergen-specific IgG and T-cell responses when compared with subcutaneous injections. Moreover, only intralymphatic immunisation stimulated the production of the Th1-dependent subclass IgG2a, which is associated with improved protection against allergen-induced anaphylaxis. Biodistribution studies showed that injection into the lymph node delivered antigen more efficiently to subcutaneous lymph nodes than subcutaneous injection. CONCLUSIONS: As intralymphatic immunisation induced more than 10-fold higher IgG2a responses with 100-fold lower allergen doses than subcutaneous immunisation, this approach should allow to reduce both the number of allergen injections as well as the allergen dose, improving both efficacy and safety of SIT.


Assuntos
Alérgenos/administração & dosagem , Dessensibilização Imunológica/métodos , Hipersensibilidade/prevenção & controle , Alérgenos/imunologia , Animais , Venenos de Abelha/imunologia , Citocinas/biossíntese , Citocinas/metabolismo , Ensaio de Imunoadsorção Enzimática , Citometria de Fluxo , Glicoproteínas/imunologia , Imunoglobulina G/sangue , Injeções Intralinfáticas , Masculino , Camundongos , Fosfolipases A2/imunologia , Linfócitos T/imunologia
17.
Mycoses ; 52(2): 99-106, 2009 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-18983424

RESUMO

Atopic patients suffering from allergic asthma, allergic rhinitis, or atopic eczema often have detectable levels of serum IgE antibodies to fungi. Although the association between fungal sensitisation and different forms of allergic diseases, including allergic asthma and life-threatening allergic bronchopulmonary aspergillosis, is well established, the clinical relevance of cross-reactivity among different fungal species remains largely unknown. Recent progress in molecular cloning of fungal allergens and the availability of more than 40 completely sequenced fungal genomes facilitates characterisation, cloning, and production of highly pure recombinant allergens, identification of homologous and orthologous allergens widespread among the fungal kingdom, in silico prediction, and experimental in vitro and in vivo verification of cross-reactivity between homologous pan-allergens. These studies indicate that cross-reactivity is an important component of fungal sensitisation.


Assuntos
Alérgenos/imunologia , Antígenos de Fungos/imunologia , Reações Cruzadas , Fungos/imunologia , Hipersensibilidade/imunologia , Asma/imunologia , Fungos/classificação , Humanos , Hipersensibilidade/etiologia , Imunoglobulina E/sangue
18.
Mol Immunol ; 46(2): 294-303, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-18922581

RESUMO

The yeast Malassezia sympodialis, which is an integral part of the normal cutaneous flora, has been shown to elicit specific IgE- and T-cell reactivity in atopic eczema (AE) patients. The M. sympodialis allergen Mala s 11 has a high degree of amino acid sequence homology to manganese superoxide dismutase (MnSOD) from Homo sapiens (50%) and Aspergillus fumigatus (56%). Humoral and cell-mediated cross-reactivity between MnSOD from H. sapiens and A. fumigatus has been demonstrated. Taken together with the recent finding that human MnSOD (hMnSOD) can act as an autoallergen in AE patients sensitised to M. sympodialis, we hypothesized that cross-reactivity could also occur between hMnSOD and Mala s 11, endogenous hMnSOD thus being capable of stimulating an immune response through molecular mimicry. Herein we demonstrate that recombinant Mala s 11 (rMala s 11) is able to inhibit IgE-binding to recombinant hMnSOD and vice versa, indicating that these two homologues share common IgE-binding epitopes and providing an explanation at a molecular level for the autoreactivity to hMnSOD observed in AE patients sensitised to Mala s 11. Using molecular modelling and mapping of identical amino acids exposed on the surface of both Mala s 11 and hMnSOD we identified four regions each composed of 4-5 residues which are potentially involved in IgE-mediated cross-reactivity. Mutated rMala s 11 molecules were produced in which these residues were altered. Native-like folding was verified by enzymatic activity tests and circular dichroism. The rMala s 11 mutants displayed lower IgE-binding in comparison to wild-type rMala s 11 using plasma from AE patients. In particular, mutation of the residues E29, P30, E122 and K125 lowered the IgE-binding to Mala s 11. The results of this study provide new insights in the molecular basis underlying the cross-reactivity between Mala s 11 and hMnSOD.


Assuntos
Alérgenos/imunologia , Proteínas Fúngicas/imunologia , Imunoglobulina E/imunologia , Malassezia/imunologia , Adulto , Alérgenos/genética , Aspergillus fumigatus/genética , Aspergillus fumigatus/imunologia , Sítios de Ligação/genética , Sítios de Ligação/imunologia , Dermatite Atópica/genética , Dermatite Atópica/imunologia , Dermatite Atópica/microbiologia , Epitopos/genética , Epitopos/imunologia , Feminino , Proteínas Fúngicas/genética , Humanos , Imunoglobulina E/genética , Malassezia/genética , Masculino , Mimetismo Molecular/genética , Mimetismo Molecular/imunologia , Mapeamento de Peptídeos/métodos , Ligação Proteica/genética , Ligação Proteica/imunologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/imunologia , Homologia de Sequência de Aminoácidos , Superóxido Dismutase/genética , Superóxido Dismutase/imunologia
19.
J Mol Biol ; 369(4): 1079-86, 2007 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-17481656

RESUMO

Atopic eczema (AE) is a chronic inflammatory disease in which genetic predisposition and environmental factors such as microorganisms contribute to the symptoms. The yeast Malassezia Sympodialis, part of the normal human cutaneous flora, can act as an allergen eliciting specific IgE and T-cell reactivity in patients with AE. The major M. sympodialis allergen Mala s 1 is localized mainly in the yeast cell wall and exposed on the cell surface. Interestingly, Mala s 1 does not exhibit any significant sequence homology to known proteins. Here we present the crystal structure of Mala s 1 determined by single-wavelength anomalous dispersion techniques using selenomethionine-substituted Mala s 1. Mala s 1 folds into a 6-fold beta-propeller, a novel fold among allergens. The putative active site of Mala s 1 overlaps structurally to putative active sites in potential homologues, Q4P4P8 and Tri 14, from the plant parasites Ustilago maydis and Gibberella zeae, respectively. This resemblance suggests that Mala s 1 and the parasite proteins may have similar functions. In addition, we show that Mala s 1 binds to the phosphoinositides (PI) PI(3)P, PI(4)P, and PI(5)P, lipids possibly playing a role in the localization of Mala s 1 to the cell surface. The crystal structure of Mala s 1 will provide insights into the role of this major allergen in the host-microbe interactions and induction of an allergic response in AE.


Assuntos
Alérgenos/química , Proteínas Fúngicas/química , Malassezia/química , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Alérgenos/genética , Alérgenos/imunologia , Sequência de Aminoácidos , Animais , Sítios de Ligação , Cristalografia por Raios X , Dermatite Atópica/imunologia , Dermatite Atópica/microbiologia , Proteínas Fúngicas/genética , Proteínas Fúngicas/imunologia , Humanos , Dados de Sequência Molecular , Dobramento de Proteína , Alinhamento de Sequência
20.
Int Arch Allergy Immunol ; 145(2): 87-93, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17823538

RESUMO

Immunoglobulin E (IgE) reactivity to self antigens is well established in vitro by ELISA, inhibition ELISA, Western blot analyses and T cell proliferation experiments. In vivo, IgE-binding self antigens are able to elicit strong type I reactions in sensitized individuals and, in the case of human manganese superoxide dismutase, to elicit eczematous reactions on healthy skin areas of patients suffering from atopic eczema. The reactions against self antigens sharing structural homology with environmental allergens can be plausibly explained by molecular mimicry between common B cell epitopes. For the second class of IgE-binding self antigens without sequence homology to known allergens, it is still unclear if the structures are able to induce a B cell switch to IgE production, or if the reactivity is due to sequence similarity shared with not yet detected environmental allergens. However, in all cases, cross-reactivity is never complete, indicating either a lower affinity of IgE antibodies to self allergens than to the homologous environmental allergens or the presence of additional B cell epitopes on the surface of the environmental allergens, or both. Increasing evidence shows that self allergens could play a decisive role in the exacerbation of long-lasting atopic diseases. However, the only observation supporting a clinical role of IgE-mediated autoreactivity is confined to the fact that IgE levels against self antigens correlate with disease severity.


Assuntos
Autoantígenos/imunologia , Imunoglobulina E/imunologia , Alérgenos/química , Alérgenos/imunologia , Especificidade de Anticorpos , Autoanticorpos/imunologia , Linfócitos B/imunologia , Reações Cruzadas , Ciclofilinas/química , Ciclofilinas/imunologia , Dermatite Atópica/imunologia , Epitopos/imunologia , Humanos , Hipersensibilidade Imediata/imunologia , Fragmentos Fab das Imunoglobulinas/imunologia , Modelos Moleculares , Mimetismo Molecular/imunologia , Conformação Proteica
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