RESUMO
Allergic disease originates in early life and polymorphisms in interleukin-33 gene (IL33) and IL1RL1, coding for IL-33R and decoy receptor sST2, confer allergy risk. Early life T helper 2 (Th2) cell skewing and allergy susceptibility are often seen as remnants of feto-maternal symbiosis. Here we report that shortly after birth, innate lymphoid type 2 cells (ILC2s), eosinophils, basophils, and mast cells spontaneously accumulated in developing lungs in an IL-33-dependent manner. During the phase of postnatal lung alveolarization, house dust mite exposure further increased IL-33, which boosted cytokine production in ILC2s and activated CD11b+ dendritic cells (DCs). IL-33 suppressed IL-12p35 and induced OX40L in neonatal DCs, thus promoting Th2 cell skewing. Decoy sST2 had a strong preventive effect on asthma in the neonatal period, less so in adulthood. Thus, enhanced neonatal Th2 cell skewing to inhaled allergens results from postnatal hyperactivity of the IL-33 axis during a period of maximal lung remodeling.
Assuntos
Asma/imunologia , Interleucina-33/imunologia , Pulmão/crescimento & desenvolvimento , Pulmão/imunologia , Células Th2/imunologia , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Hipersensibilidade/imunologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Pyroglyphidae/imunologia , Transdução de Sinais/imunologiaRESUMO
The mortality and morbidity of patients with congenital diaphragmatic hernia (CDH) is primarily caused by treatment-resistant, persistent pulmonary hypertension. Structural vascular changes, exemplified by extensive muscularization, are already present early in gestation, but the origin of these abnormalities is unknown. Understanding the origin of the vascular defects is important to improve treatment modalities. Here, we show that the distribution of pericytes is different and may thereby potentially initiate the vascular pathology in CDH. Transient inhibition of retinoic acid (RA) signaling early during pregnancy, the basis of the CDH mouse model, led to an increase in the number of pericytes, thereby affecting the angiogenic potential of pericytes in the fetuses. Pericytes of CDH lungs showed reduced proliferation and an increased ACTA2 expression, which indicates that these pericytes are more contractile than in control lung pericytes. This resulted in increased pericyte coverage of pulmonary vessels and reduced expansion of the capillary bed, the earliest pathological sign of the structural changes in CDH. Furthermore, the pericytes had reduced and altered collagen IV deposition in CDH, pointing to a loss of basal membrane integrity between pericytes and endothelial cells. Inhibition of RA signaling in vitro resulted in reduced migration of pericytes, reduced angiogenesis, and loss of collagen IV expression. Importantly, we confirmed our findings in lungs of human CDH patient samples. In summary, inhibition of RA signaling affects the lung pericyte population, leading to increased contractility, reduced pulmonary angiogenesis, and aberrant lung development, as observed in CDH.
Assuntos
Diferenciação Celular/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Hérnias Diafragmáticas Congênitas/patologia , Tretinoína/farmacologia , Animais , Modelos Animais de Doenças , Células Endoteliais/patologia , Hérnias Diafragmáticas Congênitas/tratamento farmacológico , Humanos , Hipertensão Pulmonar/tratamento farmacológico , Hipertensão Pulmonar/patologia , Pulmão/efeitos dos fármacos , Pulmão/patologia , Camundongos , Pericitos/efeitos dos fármacos , Pericitos/patologia , Transdução de Sinais/efeitos dos fármacosRESUMO
Background: Carriage of Mycoplasma pneumoniae (Mp) in the nasopharynx is considered a prerequisite for pulmonary infection. It is interesting to note that Mp carriage is also detected after infection. Although B cells are known to be involved in pulmonary Mp clearance, their role in Mp carriage is unknown. Methods: In this study, we show in a mouse model that Mp persists in the nose after pulmonary infection, similar to humans. Results: Infection of mice enhanced Mp-specific immunoglobulin (Ig) M and IgG levels in serum and bronchoalveolar lavage fluid. However, nasal washes only contained elevated Mp-specific IgA. These differences in Ig compartmentalization correlated with differences in Mp-specific B cell responses between nose- and lung-draining lymphoid tissues. Moreover, transferred Mp-specific serum Igs had no effect on nasal carriage in B cell-deficient µMT mice, whereas this enabled µMT mice to clear pulmonary Mp infection. Conclusions: We report the first evidence that humoral immunity is limited in clearing Mp from the upper respiratory tract.
Assuntos
Linfócitos B/imunologia , Portador Sadio/imunologia , Mycoplasma pneumoniae/imunologia , Nasofaringe/imunologia , Nasofaringe/microbiologia , Pneumonia por Mycoplasma/imunologia , Animais , Anticorpos Antibacterianos/sangue , Imunoglobulina A/análise , Imunoglobulina G/sangue , Camundongos Endogâmicos C57BL , Mucosa Nasal/imunologiaRESUMO
Progressive lung disease with early onset is the main cause of mortality and morbidity in cystic fibrosis patients. Here we report a reduction of sphingosine-1-phosphate (S1P) in the lung of unchallenged Cftrtm1EUR F508del CFTR mutant mice. This correlates with enhanced infiltration by inducible nitric oxide synthase (iNOS)-expressing granulocytes, B cells, and T cells. Furthermore, the ratio of macrophage-derived dendritic cells (MoDC) to conventional dendritic cells (cDC) is higher in mutant mouse lung, consistent with unprovoked inflammation. Oral application of a S1P lyase inhibitor (LX2931) increases S1P levels in mutant mouse tissues. This normalizes the lung MoDC/cDC ratio and reduces B and T cell counts. Lung granulocytes are enhanced, but iNOS expression is reduced in this population. Although lung LyC6+ monocytes are enhanced by LX2931, they apparently do not differentiate to MoDC and macrophages. After challenge with bacterial toxins (LPS-fMLP) we observe enhanced levels of proinflammatory cytokines TNF-α, KC, IFNγ, and IL-12 and the inducible mucin MUC5AC in mutant mouse lung, evidence of deficient resolution of inflammation. LX2931 does not prevent transient inflammation or goblet cell hyperplasia after challenge, but it reduces MUC5AC and proinflammatory cytokine levels toward normal values. We conclude that lung pathology in homozygous mice expressing murine F508del CFTR, which represents the most frequent mutation in CF patients, is characterized by abnormal behavior of infiltrating myeloid cells and delayed resolution of induced inflammation. This phenotype can be partially corrected by a S1P lyase inhibitor, providing a rationale for therapeutic targeting of the S1P signaling pathway in CF patients.
Assuntos
Aldeído Liases/antagonistas & inibidores , Fibrose Cística/tratamento farmacológico , Inibidores Enzimáticos/uso terapêutico , Imidazóis/uso terapêutico , Oximas/uso terapêutico , Pneumonia/tratamento farmacológico , Aldeído Liases/metabolismo , Animais , Transporte Biológico/efeitos dos fármacos , Peso Corporal/efeitos dos fármacos , Fibrose Cística/diagnóstico por imagem , Fibrose Cística/patologia , Regulador de Condutância Transmembrana em Fibrose Cística , Citocinas/metabolismo , Células Dendríticas/efeitos dos fármacos , Células Dendríticas/metabolismo , Modelos Animais de Doenças , Inibidores Enzimáticos/farmacologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Imidazóis/farmacologia , Lipopolissacarídeos/farmacologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Lisofosfolipídeos/metabolismo , Camundongos Endogâmicos C57BL , Mucina-5AC/metabolismo , Mutação/genética , Células Mieloides/efeitos dos fármacos , Células Mieloides/metabolismo , N-Formilmetionina Leucil-Fenilalanina/farmacologia , Oximas/farmacologia , Pneumonia/diagnóstico por imagem , Pneumonia/patologia , Glândulas Salivares/efeitos dos fármacos , Glândulas Salivares/metabolismo , Esfingosina/análogos & derivados , Esfingosina/metabolismo , Microtomografia por Raio-XRESUMO
In October 2016, a severe infection with swine influenza A(H1N1) virus of the Eurasian avian lineage occurred in a child with a previous history of eczema in the Netherlands, following contact to pigs. The patient's condition deteriorated rapidly and required life support through extracorporeal membrane oxygenation. After start of oseltamivir treatment and removal of mucus plugs, the patient fully recovered. Monitoring of more than 80 close unprotected contacts revealed no secondary cases.
Assuntos
Oxigenação por Membrana Extracorpórea , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Influenza Humana/diagnóstico , Infecções Respiratórias/virologia , Síndrome Respiratória Aguda Grave/terapia , Animais , Antivirais/uso terapêutico , Humanos , Influenza Humana/tratamento farmacológico , Influenza Humana/virologia , Unidades de Terapia Intensiva Pediátrica , Países Baixos , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/veterinária , Infecções por Orthomyxoviridae/virologia , Oseltamivir/uso terapêutico , Reação em Cadeia da Polimerase em Tempo Real , Infecções Respiratórias/diagnóstico , Infecções Respiratórias/tratamento farmacológico , Síndrome Respiratória Aguda Grave/complicações , Suínos , Doenças dos Suínos/transmissão , Doenças dos Suínos/virologia , Resultado do TratamentoRESUMO
In many animal models, the manifestations of inflammatory diseases can be prevented by the adoptive transfer of CD4(+)FOXP3(+) regulatory T cells (Tregs). CD4(+)FOXP3(+) Tregs can be obtained by isolation and expansion of polyclonal naturally occurring Tregs or by Ag-specific activation of CD4(+)CD25(-)FOXP3(-) T cells. Two major obstacles are hampering the translation of this latter protocol into therapeutic application. First, there is a lack of knowledge on relevant autoantigens. Second, the resulting population is contaminated with activated CD4(+) T cells that transiently express Forkhead box P3 but gain no regulatory function. Therefore, these cells may not be safe for clinical application. In this study, we demonstrate that highly suppressive FOXP3(+) Tregs can be induced in vitro by the activation of CD4(+)CD25(-) T cells with the self-Ag human 60-kDa heat shock protein (HSP60). The activation induced suppressive FOXP3(+) Tregs can be distinguished by surface expression of CD30 from nonsuppressive FOXP3(+) effector cells. We confirm that the induced CD30(+)FOXP3(+) Tregs recognize HSP60 epitopes and that the induction of Tregs by HSP60 is enhanced by signaling via TLR4 on APCs. These findings have implications for the generation and isolation of pure populations of Ag-specific Tregs, with the potential to prevent and treat human inflammatory diseases.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Chaperonina 60/farmacologia , Fatores de Transcrição Forkhead/imunologia , Antígeno Ki-1/imunologia , Linfócitos T Reguladores/imunologia , Células Apresentadoras de Antígenos/citologia , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/metabolismo , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/metabolismo , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Chaperonina 60/imunologia , Citocinas/metabolismo , Citometria de Fluxo , Fatores de Transcrição Forkhead/genética , Fatores de Transcrição Forkhead/metabolismo , Expressão Gênica/efeitos dos fármacos , Humanos , Imunofenotipagem , Antígeno Ki-1/genética , Antígeno Ki-1/metabolismo , Ativação Linfocitária/efeitos dos fármacos , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/imunologia , Linfócitos T Reguladores/citologia , Linfócitos T Reguladores/metabolismo , Receptor 4 Toll-Like/genética , Receptor 4 Toll-Like/imunologia , Receptor 4 Toll-Like/metabolismoAssuntos
Asma/sangue , Quimiocinas/sangue , Sons Respiratórios/fisiologia , Fatores Etários , Asma/fisiopatologia , Biomarcadores/sangue , Quimiocinas/fisiologia , Criança , Pré-Escolar , Feminino , Humanos , Hipersensibilidade/sangue , Hipersensibilidade/fisiopatologia , Masculino , Valor Preditivo dos TestesAssuntos
Antígenos de Dermatophagoides/imunologia , Proteínas de Artrópodes/imunologia , Cisteína Endopeptidases/imunologia , Fatores de Transcrição Forkhead/metabolismo , Fator de Transcrição GATA3/metabolismo , Hipersensibilidade/imunologia , Linfócitos T Reguladores/imunologia , Adolescente , Animais , Antígenos CD4/metabolismo , Diferenciação Celular , Células Cultivadas , Criança , Citocinas/imunologia , Feminino , Fatores de Transcrição Forkhead/genética , Fator de Transcrição GATA3/genética , Humanos , Terapia de Imunossupressão , Masculino , Pyroglyphidae , Equilíbrio Th1-Th2Assuntos
Sangue Fetal/imunologia , Receptor de Morte Celular Programada 1/imunologia , Proteínas Proto-Oncogênicas c-akt/imunologia , Tolerância a Antígenos Próprios/imunologia , Transdução de Sinais/imunologia , Linfócitos T Reguladores/imunologia , Diferenciação Celular/imunologia , Humanos , Recém-Nascido , Ativação Linfocitária/imunologia , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/imunologia , Linfócitos T Reguladores/citologiaRESUMO
Yearly more than 15 million babies are born premature (<37 weeks gestational age), accounting for more than 1 in 10 births worldwide. Lung injury caused by maternal chorioamnionitis or preeclampsia, postnatal ventilation, hyperoxia, or inflammation can lead to the development of bronchopulmonary dysplasia (BPD), one of the most common adverse outcomes in these preterm neonates. BPD patients have an arrest in alveolar and microvascular development and more frequently develop asthma and early-onset emphysema as they age. Understanding how the alveoli develop, and repair, and regenerate after injury is critical for the development of therapies, as unfortunately there is still no cure for BPD. In this review, we aim to provide an overview of emerging new concepts in the understanding of perinatal lung development and injury from a molecular and cellular point of view and how this is paving the way for new therapeutic options to prevent or treat BPD, as well as a reflection on current treatment procedures.
RESUMO
Cellular immune therapy for severe autoimmune diseases can now be considered when such patients are refractory to conventional treatment. The use of autologous stem cell transplantation (ASCT) to treat human autoimmune diseases has been initiated following promising results in a variety of animal models. Anecdotal observations have been made of autoimmune disease remission in patients who have undergone allogeneic bone marrow transplantation as a result of coincidental haematological malignancies. The possibility of inducing immunological self-tolerance by ASCT is particularly attractive as a means for treating juvenile idiopathic arthritis (JIA). In this disease, ASCT restores self-tolerance both through a cell-intrinsic mechanism, involving the reprogramming of autoreactive T cells, and through a cell-extrinsic mechanism, involving a renewal of the immune balance between CD4+CD25+ regulatory T cells and other T cells. This review describes the clinical results of ASCT performed for this disease and the possible underlying immunological mechanisms.
Assuntos
Artrite Juvenil/cirurgia , Transplante de Células-Tronco , Animais , Artrite Juvenil/imunologia , Humanos , Remissão Espontânea , Transplante Autólogo , Resultado do TratamentoRESUMO
Immunization with microbial or mammalian stress proteins or heat-shock proteins in models of experimental autoimmunity has been observed to lead to increased disease resistance. Furthermore, such immunization has been proposed to result in the induction and expansion of T cells that suppress disease upon transfer. Comparisons of microbial heat-shock proteins with other conserved immunogenic proteins of bacterial origin have indicated a unique capacity for heat-shock proteins to induce a regulatory phenotype in T cells, such as reflected by the production of IL10. Also, studies in children with chronic arthritis have indicated that T-cell responses to heat-shock proteins are associated with a benign course of the disease and with remission. Furthermore, in patients, heat-shock-protein-(HSP-) activated T cells were shown to display regulatory phenotypes consistent with CD4+ CD25+ T regulatory cells.
Assuntos
Artrite Experimental/imunologia , Proteínas de Choque Térmico/fisiologia , Linfócitos T/imunologia , Animais , Interleucina-10/biossíntese , Linfócitos T/metabolismoRESUMO
Granulocytes, monocytes, macrophages, and dendritic cells (DCs) represent a subgroup of leukocytes, collectively called myeloid cells. During the embryonic development of mammalians, myelopoiesis occurs in a stepwise fashion that begins in the yolk sac and ends up in the bone marrow (BM). During this process, these early monocyte progenitors colonize various organs such as the brain, liver, skin, and lungs and differentiate into resident macrophages that will self-maintain throughout life. DCs are constantly replenished from BM precursors but can also arise from monocytes in inflammatory conditions. In this review, we summarize the different types of myeloid cells and discuss new insights into their early origin and development in mice and humans from fetal to adult life. We specifically focus on the function of monocytes, macrophages, and DCs at these different developmental stages and on the intrinsic and environmental influences that may drive these adaptations.
RESUMO
Tissue-resident macrophages can develop from circulating adult monocytes or from primitive yolk sac-derived macrophages. The precise ontogeny of alveolar macrophages (AMFs) is unknown. By performing BrdU labeling and parabiosis experiments in adult mice, we found that circulating monocytes contributed minimally to the steady-state AMF pool. Mature AMFs were undetectable before birth and only fully colonized the alveolar space by 3 d after birth. Before birth, F4/80(hi)CD11b(lo) primitive macrophages and Ly6C(hi)CD11b(hi) fetal monocytes sequentially colonized the developing lung around E12.5 and E16.5, respectively. The first signs of AMF differentiation appeared around the saccular stage of lung development (E18.5). Adoptive transfer identified fetal monocytes, and not primitive macrophages, as the main precursors of AMFs. Fetal monocytes transferred to the lung of neonatal mice acquired an AMF phenotype via defined developmental stages over the course of one week, and persisted for at least three months. Early AMF commitment from fetal monocytes was absent in GM-CSF-deficient mice, whereas short-term perinatal intrapulmonary GM-CSF therapy rescued AMF development for weeks, although the resulting AMFs displayed an immature phenotype. This demonstrates that tissue-resident macrophages can also develop from fetal monocytes that adopt a stable phenotype shortly after birth in response to instructive cytokines, and then self-maintain throughout life.
Assuntos
Diferenciação Celular/fisiologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/metabolismo , Macrófagos Alveolares/citologia , Macrófagos Alveolares/metabolismo , Monócitos/citologia , Monócitos/metabolismo , Animais , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Células-Tronco Hematopoéticas/citologia , Células-Tronco Hematopoéticas/metabolismo , Homeostase/imunologia , Homeostase/efeitos da radiação , Imunofenotipagem , Pulmão/citologia , Pulmão/metabolismo , Camundongos , Camundongos Knockout , Fenótipo , Irradiação Corporal TotalRESUMO
BACKGROUND & AIMS: Probiotic bacteria are used as food supplement in many different disease settings. The immune modulating capacity of different strains is not always properly tested which might result in a suboptimal choice of strains for clinical use. METHODS: The CD4 T cell responses to 19 different gut derived lactic acid bacteria were tested with different methods to show their diversity in immune modulation and to make a well-founded choice on which strains to use in future clinical trials. After co-culture of PBMC with bacteria, the induction of CD4(+) T cell subsets (regulatory T cells, T helper type (TH)1, TH2 and TH17) was analysed by rtPCR of transcription factor mRNA, intracellular FACS staining of transcription factors and cytokine production. RESULTS: Bacterial strains all have diverse, unique immune modulatory properties. Strains can induce Treg, TH1, TH2 and TH17 cells which can be shown at different levels of T cell activation, and is consistent for most strains tested. For TH1, TH17 and Treg, a positive correlation between the different methods was found. For TH2 cells the correlation was less consistent. CONCLUSIONS: Probiotic bacteria have very different immune modulating capacities. Analysis of transcription factor mRNA is a suitable method for in vitro characterization of strains prior to clinical application.
Assuntos
Linfócitos T CD4-Positivos/imunologia , Lactobacillus/imunologia , Leucócitos Mononucleares/imunologia , Probióticos/farmacologia , Subpopulações de Linfócitos T/imunologia , Adulto , Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/microbiologia , Citometria de Fluxo , Humanos , Imunidade Inata/imunologia , Lactobacillus/genética , Leucócitos Mononucleares/citologia , Leucócitos Mononucleares/microbiologia , RNA Mensageiro/química , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Subpopulações de Linfócitos T/citologia , Subpopulações de Linfócitos T/microbiologiaRESUMO
Juvenile idiopathic arthritis (JIA) is a disease characterized by chronic joint inflammation, caused by a deregulated immune response. In patients with JIA, heat shock proteins (HSPs) are highly expressed in the synovial lining tissues of inflamed joints. HSPs are endogenous proteins that are expressed upon cellular stress and are able to modulate immune responses. In this review, we concentrate on the role of HSPs, especially HSP60, in modulating immune responses in both experimental and human arthritis, with a focus on JIA. We will mainly discuss the tolerogenic immune responses induced by HSPs, which could have a beneficial effect in JIA. Overall, we will discuss the immune modulatory capacity of HSPs, and the underlying mechanisms of HSP60-mediated immune regulation in JIA, and how this can be translated into therapy.
Assuntos
Artrite Juvenil/imunologia , Artrite Juvenil/patologia , Chaperonina 60/fisiologia , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/patologia , Animais , Artrite Juvenil/metabolismo , Doença Crônica , Humanos , Transdução de Sinais/imunologia , Subpopulações de Linfócitos T/metabolismoRESUMO
Despite a rapidly accumulating clinical experience with autologous stem cell transplantation (ASCT) as a treatment for severe refractory autoimmune disease, data on the mechanisms by which ASCT induces immune tolerance are still very scarce. In this study it is shown that ASCT restores immunologic self-tolerance in juvenile idiopathic arthritis (JIA) via 2 mechanisms. First, ASCT induces a restoration of the frequency of FoxP3 expressing CD4+CD25bright regulatory T cells (Tregs) from severely reduced numbers before ASCT to normal levels after ASCT. This recovery is due to a preferential homeostatic expansion of CD4+CD25+ Tregs during the lymphopenic phase of immunereconstitution, as measured by Ki67 and CD44 expression, and to a renewed thymopoiesis of naive mRNA FoxP3 expressing CD4+CD25+ Tregs after ASCT. Second, using artificial antigen-presenting cells to specifically isolate self-reactive T cells, we demonstrate that ASCT induces autoimmune cells to deviate from a proinflammatory phenotype (mRNA interferon-gamma [IFN-gamma] and T-bet high) to a tolerant phenotype (mRNA interleukin-10 [IL-10] and GATA-3 high). These data are the first to demonstrate the qualitative immunologic changes that are responsible for the induction of immune tolerance by ASCT for JIA: the restoration of the CD4+CD25+ immune regulatory network and reprogramming of autoreactive T cells.
Assuntos
Doenças Autoimunes/imunologia , Doenças Autoimunes/terapia , Antígenos CD4/sangue , Receptores de Interleucina-2/sangue , Transplante de Células-Tronco/métodos , Linfócitos T/imunologia , Transplante Autólogo , Células Apresentadoras de Antígenos/imunologia , Antígenos CD/sangue , Regulação da Expressão Gênica/imunologia , Humanos , Inflamação/imunologia , Interferon gama/genética , Interleucina-10/genética , RNA Mensageiro/genética , Tolerância a Antígenos Próprios , Transplante de Células-Tronco/efeitos adversosRESUMO
OBJECTIVE: To identify self T cell epitopes associated with proinflammatory immune responses and clinically active juvenile dermatomyositis (juvenile DM). The target of our search for relevant epitopes was represented by amino acid sequences shared between human skeletal myosin and Streptococcus pyogenes M5 protein. The long-term objective of the project is to identify suitable targets for immunotherapy of the disease. METHODS: We used computerized algorithms to identify putative agretopes on both the human myosin and Streptococcus M5 proteins. Direct binding assays for homolog peptides were used to confirm such predictions. Antigenicity and functional cross-reactivity were evaluated by cytotoxicity assays and by measurement of cytokine levels. Specific T cells were isolated by T cell capture, and T cell receptor (TCR) V(beta) gene usage was identified by reverse transcriptase-polymerase chain reaction. RESULTS: We identified peptides that are targets of disease-specific cytotoxic T cell responses. T cell reactivity against the self peptides correlates with clinical signs of early, active myositis. Such reactivity is accompanied by production of proinflammatory cytokines, which may contribute to the damage. T cell cross-recognition of bacterial and human homologs was shown functionally as well as by sorting peptide-specific T cells and identifying oligoclonal and largely overlapping TCR V(beta) gene usage. CONCLUSION: These findings represent the first identification of a self epitope in juvenile DM, providing a potential candidate for antigen-specific immune therapy.
Assuntos
Proteínas de Bactérias/imunologia , Dermatomiosite/imunologia , Epitopos/imunologia , Miosinas/imunologia , Streptococcus pyogenes/imunologia , Criança , Reações Cruzadas , Dermatomiosite/terapia , Humanos , Imunoterapia/métodos , Linfócitos T CitotóxicosRESUMO
Modulation of epitope-specific immune responses would represent a major addition to available therapeutic options for many autoimmune diseases. The objective of this work was to induce immune deviation by mucosal peptide-specific immunotherapy in rheumatoid arthritis (RA) patients, and to dissect the related immunological mechanisms by using a technology for the detection of low-affinity class II-restricted peptide-specific T cells. A group of patients with early RA was treated for 6 months orally with dnaJP1, a peptide that induces proinflammatory T cell responses in naive RA patients. Immunological analysis at initial, intermediate and end treatment points showed an intriguing change from proinflammatory to regulatory T cell function. In fact, dnaJP1-induced T cell production of IL-4 and IL-10 increased significantly when initial and end treatment points were compared, whereas dnaJP1-induced T cell proliferation and production of IL-2, IFN-gamma, and tumor necrosis factor-alpha decreased significantly. The total number of dnaJP1-specific cells did not change over time, whereas expression of foxP3 by CD4+CD25(bright) cells increased, suggesting that the treatment affected regulatory T cell function. Thus, rather than clonal deletion, the observed change in immune reactivity to dnaJP1 was the outcome of treatment-induced emergence of T cells with a different functional phenotype. This study contributes to our knowledge of mechanisms and tools needed for antigen-specific immune modulation in humans, thus laying the foundation for exploitation of this approach for therapeutic purposes.
Assuntos
Artrite Reumatoide/terapia , Epitopos/imunologia , Imunoterapia , Linfócitos T/imunologia , Adjuvantes Imunológicos/farmacologia , Artrite Reumatoide/imunologia , Linfócitos T CD4-Positivos/efeitos dos fármacos , Linfócitos T CD4-Positivos/imunologia , Proteínas de Ligação a DNA/efeitos dos fármacos , Feminino , Fatores de Transcrição Forkhead , Proteínas de Choque Térmico/farmacologia , Humanos , Imunidade nas Mucosas/efeitos dos fármacos , Imunidade nas Mucosas/imunologia , Masculino , Pessoa de Meia-Idade , Receptores de Interleucina-2/efeitos dos fármacos , Linfócitos T/efeitos dos fármacosRESUMO
This study investigates the role of CD4(+)CD25(+) regulatory T cells during the clinical course of juvenile idiopathic arthritis (JIA). Persistent oligoarticular JIA (pers-OA JIA) is a subtype of JIA with a relatively benign, self-remitting course while extended oligoarticular JIA (ext-OA JIA) is a subtype with a much less favorable prognosis. Our data show that patients with pers-OA JIA display a significantly higher frequency of CD4(+)CD25(bright) T cells with concomitant higher levels of mRNA FoxP3 in the peripheral blood than ext-OA JIA patients. Furthermore, while numbers of synovial fluid (SF) CD4(+)CD25(bright) T cells were equal in both patient groups, pers-OA JIA patients displayed a higher frequency of CD4(+)CD25(int) T cells and therefore of CD4(+)CD25(total) in the SF than ext-OA JIA patients. Analysis of FoxP3 mRNA levels revealed a high expression in SF CD4(+)CD25(bright) T cells of both patient groups and also significant expression of FoxP3 mRNA in the CD4(+)CD25(int) T cell population. The CD4(+)CD25(bright) cells of both patient groups and the CD4(+)CD25(int) cells of pers-OA JIA patients were able to suppress responses of CD25(neg) cells in vitro. A markedly higher expression of CTLA-4, glucocorticoid-induced TNFR, and HLA-DR on SF CD4(+)CD25(bright) T regulatory (Treg) cells compared with their peripheral counterparts suggests that the CD4(+)CD25(+) Treg cells may undergo maturation in the joint. In correlation with this mature phenotype, the SF CD4(+)CD25(bright) T cells showed an increased regulatory capacity in vitro compared with peripheral blood CD4(+)CD25(bright) T cells. These data suggest that CD4(+)CD25(bright) Treg cells play a role in determining the patient's fate toward either a favorable or unfavorable clinical course of disease.