RESUMO
Tissues such as the skin and mucosae are frequently exposed to microbial pathogens. Infectious agents must be quickly and efficiently controlled by our immune system, but the low frequency of naive T cells specific for any one pathogen means dependence on primary responses initiated in draining lymph nodes, often allowing time for serious infection to develop. These responses imprint effectors with the capacity to home to infected tissues; this process, combined with inflammatory signals, ensures the effective targeting of primary immunity. Upon vaccination or previous pathogen exposure, increased pathogen-specific T cell numbers together with altered migratory patterns of memory T cells can greatly improve immune efficacy, ensuring infections are prevented or at least remain subclinical. Until recently, memory T cell populations were considered to comprise central memory T cells (TCM), which are restricted to the secondary lymphoid tissues and blood, and effector memory T cells (TEM), which broadly migrate between peripheral tissues, the blood, and the spleen. Here we review evidence for these two memory populations, highlight a relatively new player, the tissue-resident memory T cell (TRM), and emphasize the potential differences between the migratory patterns of CD4(+) and CD8(+) T cells. This new understanding raises important considerations for vaccine design and for the measurement of immune parameters critical to the control of infectious disease, autoimmunity, and cancer.
Assuntos
Movimento Celular/imunologia , Memória Imunológica , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/patologia , Adaptação Fisiológica/imunologia , Animais , Humanos , Subpopulações de Linfócitos T/classificação , Distribuição Tecidual/imunologiaRESUMO
As an essential modulator of IgG disposition, the neonatal Fc receptor (FcRn) governs the pharmacokinetics and functions many therapeutic modalities. In this review, we thoroughly reexamine the hitherto elucidated biological and thermodynamic properties of FcRn to provide context for our assessment of more recent advances, which covers antigen-binding fragment (Fab) determinants of FcRn affinity, transgenic preclinical models, and FcRn targeting as an immune-complex (IC)-clearing strategy. We further comment on therapeutic antibodies authorized for treating SARS-CoV-2 (bamlanivimab, casirivimab, and imdevimab) and evaluate their potential to saturate FcRn-mediated recycling. Finally, we discuss modeling and simulation studies that probe the quantitative relationship between in vivo IgG persistence and in vitro FcRn binding, emphasizing the importance of endosomal transit parameters.
Assuntos
Antígenos de Histocompatibilidade Classe I/química , Antígenos de Histocompatibilidade Classe I/metabolismo , Receptores Fc/química , Receptores Fc/metabolismo , Animais , Anticorpos Monoclonais/metabolismo , Anticorpos Monoclonais/farmacocinética , Antígenos de Histocompatibilidade Classe I/imunologia , Humanos , Imunoglobulina G/imunologia , Imunoglobulina G/metabolismo , Receptores Fc/imunologia , Distribuição Tecidual/imunologia , Tratamento Farmacológico da COVID-19RESUMO
Non-invasively monitoring allogeneic graft rejection with a specific marker is of great importance for prognosis of patients. Recently, data revealed that IL-27Rα was up-regulated in alloreactive CD4+ T cells and participated in inflammatory diseases. Here, we evaluated whether IL-27Rα could be used in monitoring allogeneic graft rejection both in vitro and in vivo. Allogeneic (C57BL/6 donor to BALB/c recipient) and syngeneic (BALB/c both as donor and recipient) skin grafted mouse models were established. The expression of IL-27Rα in grafts was detected. The radio-probe, 125I-anti-IL-27Rα mAb, was prepared. Dynamic whole-body phosphor-autoradiography, ex vivo biodistribution and immunofluorescence staining were performed. The results showed that the highest expression of IL-27Rα was detected in allogeneic grafts on day 10 post transplantation (top period of allorejection). 125I-anti-IL-27Rα mAb was successfully prepared with higher specificity and affinity. Whole-body phosphor-autoradiography showed higher radioactivity accumulation in allogeneic grafts than syngeneic grafts on day 10. The uptake of 125I-anti-IL-27Rα mAb in allogeneic grafts could be almost totally blocked by pre-injection with excess unlabeled anti-IL-27Rα mAb. Interestingly, we found that 125I-anti-IL-27Rα mAb accumulated in allogeneic grafts, along with weaker inflammation earlier on day 6. The high uptake of 125I-anti-IL-27Rα mAb was correlated with the higher infiltrated IL-27Rα positive cells (CD3+/CD68+) in allogeneic grafts. In conclusion, IL-27Rα may be a novel molecular imaging marker to predict allorejection.
Assuntos
Biomarcadores/metabolismo , Rejeição de Enxerto/genética , Imagem Molecular , Receptores de Interleucina/genética , Aloenxertos , Animais , Anticorpos Monoclonais/imunologia , Regulação da Expressão Gênica no Desenvolvimento/genética , Rejeição de Enxerto/imunologia , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Receptores de Interleucina/isolamento & purificação , Receptores de Interleucina/metabolismo , Transplante de Pele/efeitos adversos , Linfócitos T/imunologia , Linfócitos T/metabolismo , Distribuição Tecidual/imunologia , Transplante HomólogoRESUMO
BACKGROUND: Epidermal growth factor (EGF) can promote cell proliferation as well as migration, which is feasible in tissue wound healing. Oil bodies have been exploited as an important platform to produce exogenous proteins. The exogenous proteins were expressed in oil bodies from plant seeds. The process can reduce purification steps, thereby significantly reducing the purification cost. Mostly, the diameter of oil body particle ranges between 1.0 and 1.5 µm in the safflower seeds, however, it reduces to 700-1000 nm in the transgenic safflower seeds. The significant reduction of particle size in transgenic seeds is extremely beneficial to skin absorption. RESULTS: The diameter of oil body in the transgenic safflower seeds was recorded in the range of 700-1000 nm. The smaller particle size improved their skin absorption. The expression level of oleosin-hEGF-hEGF in T3 transgenic seeds was highest at 69.32 mg/g of seeds. The oil body expressing oleosin-hEGF-hEGF had significant proliferative activity on NIH/3T3 cells and improved skin regeneration thereby accelerating wound healing in rats. The wound coverage rate exceeded 98% after treatment for 14 days with oil body expressing oleosin-hEGF-hEGF, while the saline without EGF group and wild type oil body group both showed less than 80%. The neonatal fibroblast and collagen were found to be increased in the safflower oil body expressing oleosin-hEGF-hEGF treatment group. TGF-ß1, bFGF and VEGF were noted as important growth factors in the repair of cutaneous wounds. Their expression level increased after 4 and 7 day treatment, but decreased after 14 days. Therefore, it can promote skin regeneration to accelerate wounds healing. CONCLUSIONS: The expression of oleosin-hEGF-hEGF in T3 transgenic seeds was 80.43 ng/µL oil body. It had significant proliferative activity on NIH/3T3 cells and improved skin regeneration to accelerate wound healing in rats. The expression process of TGF-ß1, bFGF and VEGF increased at first and then gradually declined.
Assuntos
Fator de Crescimento Epidérmico/química , Gotículas Lipídicas/química , Proteínas de Plantas/química , Pele/metabolismo , Cicatrização/efeitos dos fármacos , Animais , Proliferação de Células/efeitos dos fármacos , Portadores de Fármacos/química , Portadores de Fármacos/uso terapêutico , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos ICR , Células NIH 3T3 , Tamanho da Partícula , Óleos de Plantas/química , Ratos , Ratos Wistar , Regeneração/efeitos dos fármacos , Sementes/química , Propriedades de Superfície , Distribuição Tecidual/efeitos dos fármacos , Distribuição Tecidual/imunologiaRESUMO
BACKGROUND: Preclinical research implementing fluorescence-based approaches is inevitable for drug discovery and technology. For example, a variety of contrast agents developed for biomedical imaging are usually evaluated in cell systems and animal models based on their conjugation to fluorescent dyes. Biodistribution studies of excised organs are often performed by macroscopic imaging, whereas the subcellular localization though vital, is often neglected or further validated by histological procedures. Available systems used to define the subcellular biodistribution of contrast agents such as intravital microscopes or ex vivo histological analysis are expensive and not affordable by the majority of researchers, or encompass tedious and time consuming steps that may modify the contrast agents and falsify the results. Thus, affordable and more reliable approaches to study the biodistribution of contrast agents are required. We developed fluorescent immunoliposomes specific for human fibroblast activation protein and murine endoglin, and used macroscopic fluorescence imaging and confocal microscopy to determine their biodistribution and subcellular localization in freshly excised mice organs at different time points post intravenous injection. RESULTS: Near infrared fluorescence macroscopic imaging revealed key differences in the biodistribution of the respective immunoliposomes at different time points post injection, which correlated to the first-pass effect as well as the binding of the probes to molecular targets within the mice organs. Thus, a higher accumulation and longer retention of the murine endoglin immunoliposomes was seen in the lungs, liver and kidneys than the FAP specific immunoliposomes. Confocal microscopy showed that tissue autofluorescence enables detection of organ morphology and cellular components within freshly excised, non-processed organs, and that fluorescent probes with absorption and emission maxima beyond the tissue autofluorescence range can be easily distinguished. Hence, the endoglin targeting immunoliposomes retained in some organs could be detected in the vascular endothelia cells of the organs. CONCLUSIONS: The underlying work represents a quick, effective and more reliable setup to validate the macroscopic and subcellular biodistribution of contrast agents in freshly excised animal organs. The approach will be highly beneficial to many researchers involved in nanodrug design or in fluorescence-based studies on disease pathogenesis.
Assuntos
Anticorpos Monoclonais/imunologia , Lipossomos/imunologia , Microscopia de Fluorescência/métodos , Imagem Molecular/métodos , Frações Subcelulares/imunologia , Vísceras/imunologia , Animais , Feminino , Técnicas In Vitro , Taxa de Depuração Metabólica/imunologia , Camundongos , Camundongos Nus , Microscopia Confocal/métodos , Especificidade de Órgãos/imunologia , Distribuição Tecidual/imunologiaRESUMO
PURPOSE: A double-mutant E224A/E262A full-length botulinum neurotoxin (BoNT) Type A with structural similarity to native BoNT/A but lacking the endopeptidase activity provides an ideal surrogate for testing pharmacokinetics and immunochemical characteristics of BoNT. METHODS: We determined lethality (LD50) of deactivated recombinant botulinum neurotoxin (drBoNT/A) to be 24.0 µg by intraperitoneal route (i.p). The polypeptide drBoNT/A labeled with near infra-red dye 800 (NIR 800) was used to examine its distribution to different organs using whole body imaging when administered to mice via intravenous (i.v) or i.p route. Also, drBoNT/A was used to evaluate its immunogenicity in Balb/C mice model. RESULTS: drBoNT/A was found to be highly immunogenic when tested under various in vivo conditions in Balb/C mice model. For the first time we have demonstrated that a full length 150 kDa drBoNT/A, by administering via inhalation route in mice model, has evoked both circulating immunoglobulin levels of IgG and secretory IgA at the mucosal surface. The immunoglobulin levels were sufficient enough to protect against the challenge dose of native BoNT toxin in mice model. Tissue distribution of drBoNT/A seems to be similar to that of native toxin. CONCLUSIONS: Based on the characteristics described in this report this nontoxic holotoxin protein will assist us to explore the window of opportunity available for therapeutic treatment in case of unnatural poisoning, and also it can be an effective vaccine candidate.
Assuntos
Formação de Anticorpos/imunologia , Toxinas Botulínicas Tipo A/imunologia , Proteínas Recombinantes/imunologia , Animais , Linhagem Celular Tumoral , Feminino , Imunoglobulina A Secretora/imunologia , Imunoglobulina G/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Distribuição Tecidual/imunologiaRESUMO
The autoimmune regulator is a critical transcription factor for generating central tolerance in the thymus. Recent studies have revealed how the autoimmune regulator targets many otherwise tissue-restricted Ag genes to enable negative selection of autoreactive T cells.
Assuntos
Antígenos/genética , Regulação da Expressão Gênica/imunologia , Fatores de Transcrição/fisiologia , Motivos de Aminoácidos/genética , Animais , Antígenos/biossíntese , Antígenos/química , Sequência Conservada/imunologia , Humanos , Tolerância Imunológica/genética , Camundongos , Camundongos Knockout , Poliendocrinopatias Autoimunes/genética , Poliendocrinopatias Autoimunes/imunologia , Poliendocrinopatias Autoimunes/metabolismo , Mapeamento de Interação de Proteínas/métodos , Distribuição Tecidual/genética , Distribuição Tecidual/imunologia , Fatores de Transcrição/química , Proteína AIRERESUMO
Genome-wide association studies of complex immune-mediated diseases have indicated that many genetic factors, each with individual low risk, contribute to overall disease. It is therefore timely and important to characterize how immune responses may be subtly modified by tissue context. In this article, we explore the role of tissue-derived molecules in influencing the function of T cells, which, owing to their migratory nature, come into contact with many different microenvironments through their lifespan. Hedgehog (Hh) proteins act as secreted morphogens, providing concentration-dependent positional and temporal cell-fate specification in solid tissues. Hh signaling is required for embryogenesis and is important in postnatal tissue renewal and in malignancy. However, the function of Hh in dynamic, fluid systems, such as in mammalian immunity, is largely unknown. In this article, we show that Hh-dependent transcription in T cells promoted Th2 transcriptional programs and differentiation, exacerbating allergic disease. Of interest, expression of Sonic Hh increased in lung epithelial cells following the induction of allergic disease, and lung T cells upregulated Hh target gene expression, indicating that T cells respond to locally secreted Hh ligands in vivo. We show that Il4, the key Th2 cytokine, is a novel transcriptional target of Hh signals in T cells, providing one mechanism for the role of Hh in Th differentiation. We propose that Hh, secreted from inflamed, remodeling, or malignant tissue, can modulate local T cell function. Our data present an unexpected and novel role for tissue-derived morphogens in the regulation of fluid immune responses, with implications for allergy and tumor responses, suggesting new uses for anti-Hh therapeutics.
Assuntos
Asma/imunologia , Asma/metabolismo , Diferenciação Celular/imunologia , Proteínas Hedgehog/fisiologia , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Auxiliares-Indutores/metabolismo , Animais , Asma/patologia , Células Cultivadas , Proteínas Hedgehog/antagonistas & inibidores , Proteínas Hedgehog/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/imunologia , Linfócitos T Auxiliares-Indutores/patologia , Distribuição Tecidual/imunologia , Transcrição Gênica/imunologiaRESUMO
TLRs are essential for sensing the invading pathogens and initiating protective immune responses. However, aberrant activation of TLR-triggered inflammatory innate responses leads to the inflammatory disorders and autoimmune diseases. The molecular mechanisms that fine-tune TLR responses remain to be fully elucidated. Protein tyrosine phosphatase with proline-glutamine-serine-threonine-rich motifs (PTP-PEST) has been shown to be important in cell adhesion, migration, and also T cell and B cell activation. However, the roles of PTP-PEST in TLR-triggered immune response remain unclear. In this study, we report that PTP-PEST expression was upregulated in macrophages by TLR ligands. PTP-PEST inhibited TNF-α, IL-6, and IFN-ß production in macrophages triggered by TLR3, TLR4, and TLR9. Overexpression of catalytically inactive mutants of PTP-PEST abolished the inhibitory effects, indicating that PTP-PEST inhibits TLR response in a phosphatase-dependent manner. Accordingly, PTP-PEST knockdown increased TLR3, -4, and -9-triggered proinflammatory cytokine and type I IFN production. PTP-PEST selectively inhibited TLR-induced NF-κB activation, whereas it had no substantial effect on MAPK and IFN regulatory factor 3 activation. Moreover, PTP-PEST directly interacted with IκB kinase ß (IKKß) then inhibited IKKß phosphorylation at Ser(177/181) and Tyr(188/199), and subsequently suppressed IKKß activation and kinase activity as well as downstream NF-κB activation, resulting in suppression of the TLR-triggered innate immune response. Thus, PTP-PEST functions as a feedback-negative regulator of TLR-triggered innate immune responses by selectively impairing IKKß/NF-κB activation.
Assuntos
Regulação para Baixo/imunologia , Quinase I-kappa B/antagonistas & inibidores , Imunidade Inata , NF-kappa B/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 12/química , Proteína Tirosina Fosfatase não Receptora Tipo 12/fisiologia , Receptores Toll-Like/fisiologia , Motivos de Aminoácidos/genética , Motivos de Aminoácidos/imunologia , Animais , Linhagem Celular , Células Cultivadas , Regulação para Baixo/genética , Glutamina/metabolismo , Células HEK293 , Humanos , Quinase I-kappa B/genética , Quinase I-kappa B/metabolismo , Imunidade Inata/genética , Macrófagos Peritoneais/enzimologia , Macrófagos Peritoneais/imunologia , Macrófagos Peritoneais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , NF-kappa B/genética , NF-kappa B/metabolismo , Prolina/metabolismo , Mapeamento de Interação de Proteínas/métodos , Proteína Tirosina Fosfatase não Receptora Tipo 12/biossíntese , Serina/metabolismo , Treonina/metabolismo , Distribuição Tecidual/genética , Distribuição Tecidual/imunologia , Receptores Toll-Like/antagonistas & inibidores , Receptores Toll-Like/genéticaRESUMO
Radioimmunotherapy (RIT) of solid tumors is hampered by low tumor-to-nontumor (T/NT) ratios of the radiolabeled monoclonal antibodies resulting in low tumor doses in patients. Pretargeting technologies can improve the effectiveness of RIT in cancer therapy by increasing this ratio. We showed that a pretargeting strategy employing in vivo chemistry in combination with clearing agents, proceeds efficiently in tumor-bearing mice resulting in high T/NT ratios. A dosimetry study indicated that the chemical pretargeting technology, which centered on the bioorthogonal Diels-Alder click reaction between a radiolabeled tetrazine probe and a trans-cyclooctene-oxymethylbenzamide-tagged CC49 antibody (CC49-TCO(1)), can match the performance of clinically validated high-affinity biological pretargeting approaches in mice ( Rossin J Nucl Med. 2013 , 54 , 1989 - 1995 ). Nevertheless, the increased protein surface hydrophobicity of CC49-TCO(1) led to a relatively rapid blood clearance and concomitant reduced tumor uptake compared to native CC49 antibody. Here, we present the in vivo evaluation of a TCO-oxymethylacetamide-tagged CC49 antibody (CC49-TCO(2)), which is highly reactive toward tetrazines and less hydrophobic than CC49-TCO(1). CC49-TCO(2) was administered to healthy mice to determine its blood clearance and the in vivo stability of the TCO. Next, pretargeting biodistribution and SPECT studies with CC49-TCO(2), tetrazine-functionalized clearing agent, and radiolabeled tetrazine were carried out in nude mice bearing colon carcinoma xenografts (LS174T). CC49-TCO(2) had an increased circulation half-life, a 1.5-fold higher tumor uptake, and a 2.6-fold improved in vivo TCO stability compared to the more hydrophobic TCO-benzamide-CC49. As a consequence, and despite the 2-fold lower reactivity of CC49-TCO(2) toward tetrazines compared with CC49-TCO(1), administration of radiolabeled tetrazine afforded a significantly increased tumor accumulation and improved T/NT ratios in mice pretargeted with CC49-TCO(2). In conclusion, the TCO-acetamide derivative represents a large improvement in in vivo Diels-Alder pretargeting, possibly enabling application in larger animals and eventually humans.
Assuntos
Neoplasias do Colo/tratamento farmacológico , Neoplasias do Colo/radioterapia , Ciclo-Octanos/química , Ciclo-Octanos/uso terapêutico , Imunoconjugados/química , Imunoconjugados/farmacologia , Animais , Anticorpos Monoclonais/química , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/farmacologia , Carcinoma/tratamento farmacológico , Carcinoma/imunologia , Carcinoma/radioterapia , Linhagem Celular Tumoral , Neoplasias do Colo/imunologia , Reação de Cicloadição/métodos , Ciclo-Octanos/imunologia , Feminino , Meia-Vida , Humanos , Imunoconjugados/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Radioimunoterapia/métodos , Radiometria/métodos , Compostos Radiofarmacêuticos/química , Compostos Radiofarmacêuticos/imunologia , Compostos Radiofarmacêuticos/farmacologia , Distribuição Tecidual/imunologiaRESUMO
PURPOSE: To monitor the biodistribution of IgG1 aggregates upon subcutaneous (SC) and intravenous (IV) administration in mice and measure their propensity to stimulate an early immune response. METHODS: A human mAb (IgG1) was fluorescently labeled, aggregated by agitation stress and injected in SKH1 mice through SC and IV routes. The biodistribution of monomeric and aggregated formulations was monitored over 47 days by fluorescence imaging and the early immune response was measured by quantifying the level of relevant cytokines in serum using a Bio-plex assay. RESULTS: The aggregates remained at the SC injection site for a longer time than monomers but after entry into the systemic circulation disappeared faster than monomers. Upon IV administration, both monomers and aggregates spread rapidly throughout the circulation, and a strong accumulation in the liver was observed for both species. Subsequent removal from the circulation was faster for aggregates than monomers. No accumulation in lymph nodes was observed after SC or IV administration. Administration of monomers and aggregates induced similar cytokine levels, but SC injection resulted in higher cytokine levels than IV administration. CONCLUSION: These results show differences in biodistribution and residence time between IgG1 aggregates and monomers. The long residence time of aggregates at the SC injection site, in conjunction with elevated cytokine levels, may contribute to an enhanced immunogenicity risk of SC injected aggregates compared to that of monomers.
Assuntos
Imunoglobulina G/imunologia , Distribuição Tecidual/imunologia , Animais , Anticorpos Monoclonais/imunologia , Citocinas/imunologia , Feminino , Fluorescência , Humanos , Injeções Intravenosas/métodos , Injeções Subcutâneas/métodos , Linfonodos/imunologia , Camundongos , Imagem Óptica/métodosRESUMO
The closely linked human IL-3 and GM-CSF genes are tightly regulated and are expressed in activated T cells and mast cells. In this study, we used transgenic mice to study the developmental regulation of this locus and to identify DNA elements required for its correct activity in vivo. Because these two genes are separated by a CTCF-dependent insulator, and the GM-CSF gene is regulated primarily by its own upstream enhancer, the main objective in this study was to identify regions of the locus required for correct IL-3 gene expression. We initially found that the previously identified proximal upstream IL-3 enhancers were insufficient to account for the in vivo activity of the IL-3 gene. However, an extended analysis of DNase I-hypersensitive sites (DHSs) spanning the entire upstream IL-3 intergenic region revealed the existence of a complex cluster of both constitutive and inducible DHSs spanning the -34- to -40-kb region. The tissue specificity of these DHSs mirrored the activity of the IL-3 gene, and included a highly inducible cyclosporin A-sensitive enhancer at -37 kb that increased IL-3 promoter activity 40-fold. Significantly, inclusion of this region enabled correct in vivo regulation of IL-3 gene expression in T cells, mast cells, and myeloid progenitor cells.
Assuntos
Elementos Facilitadores Genéticos/imunologia , Regulação da Expressão Gênica no Desenvolvimento/imunologia , Fator Estimulador de Colônias de Granulócitos e Macrófagos/biossíntese , Fator Estimulador de Colônias de Granulócitos e Macrófagos/genética , Interleucina-3/biossíntese , Interleucina-3/genética , Animais , Linhagem Celular , Linhagem Celular Tumoral , Células Cultivadas , Desoxirribonuclease I/genética , Elementos Facilitadores Genéticos/genética , Loci Gênicos/imunologia , Humanos , Células Jurkat , Camundongos , Camundongos Transgênicos , Distribuição Tecidual/genética , Distribuição Tecidual/imunologiaRESUMO
The development of chronic allergic dermatitis in early life has been associated with increased onset and severity of allergic asthma later in life. However, the mechanisms linking these two diseases are poorly understood. In this study, we report that the development of oxazolone-induced chronic allergic dermatitis, in a mouse model, caused enhanced OVA-induced allergic asthma after the resolution of the former disease. Our findings show that oxazolone-induced dermatitis caused a marked increase in tissue mast cells, which persisted long after the resolution of this disease. Subsequent OVA sensitization and airway challenge of mice that had recovered from dermatitis resulted in increased allergic airway hyperreactivity. The findings demonstrate that the accumulation of mast cells during dermatitis has the detrimental effect of increasing allergic airway hypersensitivity. Importantly, our findings also show that exposure to a given allergen can modify the immune response to an unrelated allergen.
Assuntos
Dermatite Atópica/imunologia , Dermatite Atópica/patologia , Mastócitos/imunologia , Mastócitos/patologia , Hipersensibilidade Respiratória/imunologia , Hipersensibilidade Respiratória/patologia , Animais , Hiper-Reatividade Brônquica/imunologia , Hiper-Reatividade Brônquica/patologia , Contagem de Células , Doença Crônica , Dermatite Atópica/induzido quimicamente , Modelos Animais de Doenças , Progressão da Doença , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Ovalbumina/administração & dosagem , Oxazolona/administração & dosagem , Distribuição Tecidual/genética , Distribuição Tecidual/imunologiaRESUMO
Differentiation and maintenance of recirculating effector memory CD8 T cells (T(EM)) depends on prolonged cognate Ag stimulation. Whether similar pathways of differentiation exist for recently identified tissue-resident effector memory T cells (T(RM)), which contribute to rapid local protection upon pathogen re-exposure, is unknown. Memory CD8αß(+) T cells within small intestine epithelium are well-characterized examples of T(RM), and they maintain a long-lived effector-like phenotype that is highly suggestive of persistent Ag stimulation. This study sought to define the sources and requirements for prolonged Ag stimulation in programming this differentiation state, including local stimulation via cognate or cross-reactive Ags derived from pathogens, microbial flora, or dietary proteins. Contrary to expectations, we found that prolonged cognate Ag stimulation was dispensable for intestinal T(RM) ontogeny. In fact, chronic antigenic stimulation skewed differentiation away from the canonical intestinal T cell phenotype. Resident memory signatures, CD69 and CD103, were expressed in many nonlymphoid tissues including intestine, stomach, kidney, reproductive tract, pancreas, brain, heart, and salivary gland and could be driven by cytokines. Moreover, TGF-ß-driven CD103 expression was required for T(RM) maintenance within intestinal epithelium in vivo. Thus, induction and maintenance of long-lived effector-like intestinal T(RM) differed from classic models of T(EM) ontogeny and were programmed through a novel location-dependent pathway that was required for the persistence of local immunological memory.
Assuntos
Diferenciação Celular/imunologia , Epitopos de Linfócito T/fisiologia , Memória Imunológica/imunologia , Subpopulações de Linfócitos T/imunologia , Animais , Linhagem Celular , Feminino , Imunofenotipagem , Mucosa Intestinal/imunologia , Mucosa Intestinal/patologia , Mucosa Intestinal/virologia , Vírus da Coriomeningite Linfocítica/imunologia , Vírus da Coriomeningite Linfocítica/patogenicidade , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Camundongos Transgênicos , Especificidade de Órgãos/imunologia , Transdução de Sinais/imunologia , Subpopulações de Linfócitos T/patologia , Subpopulações de Linfócitos T/virologia , Fatores de Tempo , Distribuição Tecidual/imunologiaRESUMO
B7x (B7-H4 or B7S1), a member of the B7 family, inhibits in vitro T cell proliferation and cytokine production by binding to an unidentified receptor on activated T cells, but its in vivo function remains largely unclear. We show that B7x protein was expressed in epithelial cells of the lung, but not in lymphoid tissues. To investigate the role of B7x in the lung, we determined the susceptibility of B7x-deficient (B7x(-/-)) mice to a lethal pulmonary infection with Streptococcus pneumoniae. B7x(-/-), but not B7-H3-deficient, mice were significantly more resistant to S. pneumoniae pulmonary infection than their wild-type (Wt) counterparts. B7x(-/-) mice had significantly lower bacterial burdens and levels of inflammatory cytokines in lungs as early as 12 h postinfection. They also had milder immunopathology that was localized in alveolar spaces, whereas Wt mice had severe inflammation that was perivascular. Control of infection in B7x(-/-) mice was associated with a marked increase in activated CD4 and CD8 T cells and fewer neutrophils in lungs, whereas the susceptible Wt mice had the opposite cellular profile. In B7x(-/-)Rag1(-/-) mice that lack T cells, reduction in bacterial burden was no longer observed. Control of S. pneumoniae and the increased survival observed was specific to the lung, because systemically infected B7x(-/-) mice were not resistant to infection. These data indicate that lung-expressed B7x negatively regulates T cells, and that in its absence, in B7x(-/-) mice, an enhanced T cell response contributed to reduced lethality in a pulmonary infection model with S. pneumoniae.
Assuntos
Pneumonia Pneumocócica/imunologia , Inibidor 1 da Ativação de Células T com Domínio V-Set/fisiologia , Animais , Resistência à Doença/genética , Resistência à Doença/imunologia , Pulmão/imunologia , Pulmão/microbiologia , Pulmão/patologia , Tecido Linfoide/imunologia , Tecido Linfoide/microbiologia , Tecido Linfoide/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Avaliação de Resultados em Cuidados de Saúde , Pneumonia Pneumocócica/mortalidade , Pneumonia Pneumocócica/patologia , Análise de Sobrevida , Linfócitos T/imunologia , Linfócitos T/microbiologia , Linfócitos T/patologia , Distribuição Tecidual/genética , Distribuição Tecidual/imunologia , Inibidor 1 da Ativação de Células T com Domínio V-Set/deficiência , Inibidor 1 da Ativação de Células T com Domínio V-Set/genéticaRESUMO
Ectoenzymes expressed on the surface of vascular cells and leukocytes modulate the ambient nucleotide milieu. CD73 is an ecto-5' nucleotidase that catalyzes the terminal phosphohydrolysis of AMP and resides in the brain on glial cells, cells of the choroid plexus, and leukocytes. Though CD73 tightens epithelial barriers, its role in the ischemic brain remains undefined. When subjected to photothrombotic arterial occlusion, CD73(-/-) mice exhibited significantly larger (49%) cerebral infarct volumes than wild-type mice, with concordant increases in local accumulation of leukocyte subsets (neutrophils, T lymphocytes, macrophages, and microglia). CD73(-/-) mice were rescued from ischemic neurologic injury by soluble 5'-nucleotidase. In situ, CD73(-/-) macrophages upregulated expression of costimulatory molecules far more than wild-type macrophages, with a sharp increase of the CD80/CD86 ratio. To define the CD73-bearing cells responsible for ischemic cerebroprotection, mice were subjected to irradiative myeloablation, marrow reconstitution, and then stroke following engraftment. Chimeric mice lacking CD73 in tissue had larger cerebral infarct volumes and more tissue leukosequestration than did mice lacking CD73 on circulating cells. These data show a cardinal role for CD73 in suppressing ischemic tissue leukosequestration. This underscores a critical role for CD73 as a modulator of brain inflammation and immune function.
Assuntos
5'-Nucleotidase/fisiologia , Isquemia Encefálica/imunologia , Isquemia Encefálica/patologia , Movimento Celular/genética , Movimento Celular/imunologia , Leucócitos/imunologia , Leucócitos/patologia , 5'-Nucleotidase/deficiência , 5'-Nucleotidase/genética , Adenosina/biossíntese , Adenosina/fisiologia , Animais , Transplante de Medula Óssea/imunologia , Transplante de Medula Óssea/patologia , Edema Encefálico/enzimologia , Edema Encefálico/imunologia , Edema Encefálico/patologia , Isquemia Encefálica/enzimologia , Líquido Extracelular/enzimologia , Líquido Extracelular/imunologia , Infarto da Artéria Cerebral Média/enzimologia , Infarto da Artéria Cerebral Média/imunologia , Infarto da Artéria Cerebral Média/patologia , Inflamação/enzimologia , Inflamação/imunologia , Inflamação/prevenção & controle , Leucócitos/enzimologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/genética , Transdução de Sinais/imunologia , Distribuição Tecidual/genética , Distribuição Tecidual/imunologiaRESUMO
Memory T cells (T(M)s) have been detected in many tissues but their quantitative distribution remains largely undefined. We show that in mice there is a remarkably biased accumulation of long-term CD4 T(M)s into mucosal sites (mainly gut, especially Peyer patches), and CD8 T(M)s into lymph nodes and spleen (in particular, peripheral lymph nodes [PLNs]). This distinction correlates with their differentiated expression of PLN- and gut-homing markers. CD8 and CD4 T(M)s selectively require the expression of PLN-homing marker CCR7 or gut-homing marker α4ß7 for maintenance. PLNs and gut supply CD8 and CD4 T(M)s with their individually favored homeostatic cytokine, IL-15, or IL-7. Cytokine stimulation in turn regulates the different gut-homing marker expression on CD4 and CD8 T(M)s. IL-15 plays a major role in vivo regulating CD8 T(M)s homing to PLNs. Thus, the reservoir segregation of CD4 and CD8 T(M)s meets their individual needs for homeostatic cytokines and is under feedback control of cytokine stimulation.
Assuntos
Linfócitos T CD4-Positivos/fisiologia , Linfócitos T CD8-Positivos/fisiologia , Quimiotaxia de Leucócito/fisiologia , Citocinas/fisiologia , Animais , Biomarcadores/análise , Biomarcadores/metabolismo , Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/metabolismo , Células Cultivadas , Quimiotaxia de Leucócito/imunologia , Citocinas/metabolismo , Feminino , Homeostase/imunologia , Humanos , Linfonodos/citologia , Linfonodos/imunologia , Linfonodos/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Nicho de Células-Tronco/imunologia , Distribuição Tecidual/imunologiaRESUMO
Overproduction of periostin, an IL-13-inducible matricellular protein, despite corticosteroid treatment is thought to be involved in the chronicity of allergic inflammation seen in corticosteroid-refractory tissue fibrosis. Therefore, we hypothesized that some tissue cells must produce periostin in a corticosteroid-insensitive manner. Here, we show that IL-4 and IL-13 each induced comparable levels of periostin production by primary normal human fibroblasts and microvascular endothelial cells derived from lung and skin. Dexamethasone, a corticosteroid, completely inhibited IL-4/13-induced, but did not affect TGF-ß-induced, periostin production by fibroblasts. In contrast, dexamethasone synergistically enhanced IL-4/13-induced periostin production by microvascular endothelial cells. TGF-ß did not induce periostin production by microvascular endothelial cells. Our novel findings suggest that IL-4/13-induced microvascular endothelium-derived and/or TGF-ß-induced fibroblast-derived periostin might play a pivotal role in corticosteroid-refractory tissue fibrosis, leading to chronic allergic inflammation in the lung and/or skin.
Assuntos
Moléculas de Adesão Celular/biossíntese , Dexametasona/farmacologia , Moléculas de Adesão Celular/antagonistas & inibidores , Sistema Livre de Células , Fibroblastos/imunologia , Fibroblastos/patologia , Fibrose/imunologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Mediadores da Inflamação/fisiologia , Interleucina-13/fisiologia , Interleucina-4/fisiologia , Pulmão/imunologia , Pulmão/patologia , Pele/imunologia , Pele/patologia , Distribuição Tecidual/imunologia , Fator de Crescimento Transformador beta1/fisiologiaRESUMO
Accumulating evidence suggests that overexpression of the tyrosine kinase receptor EphB4, a mediator of vascular development, is a novel target for tumor diagnosis, prognosis and therapy. Noninvasive imaging of EphB4 expression could therefore be valuable for evaluating disease course and therapeutic efficacy at the earliest stages of anti-EphB4 treatment. In this study, we systematically investigated the use of anti-EphB4 antibody h131 (150 kDa) and its fragments (h131-F(ab')2, 110 kDa; h131-Fab, 50 kDa) for near-infrared fluorescence (NIRF) imaging of EphB4 expression in vivo. h131-F(ab')2 and h131-Fab were produced through pepsin and papain digestion of h131 respectively, whose purity was confirmed by FPLC and SDS-PAGE. After conjugation with Cy5.5, in vivo characteristics of h131, h131-F(ab')2 and h131-Fab were evaluated in EphB4-positive HT29 tumor model. Although h131-Cy5.5 demonstrated highest tumor uptake among these probes, its optimal tumor uptake level was obtained at 2 days post injection (p.i.). For h131-Fab-Cy5.5, maximum tumor uptake was achieved at 4 h p.i. However, no significant difference was observed between h131-Fab-Cy5.5 and hIgG-Fab-Cy5.5, indicating the tumor accumulation was mainly caused by passive targeting. In contrast, h131-F(ab')2-Cy5.5 demonstrated prominent tumor uptake at 6 h p.i. The target specificity was confirmed by hIgG-F(ab')2-Cy5.5 control and immunofluorescent staining. Collectively, h131-F(ab')2 exhibited prominent and specific tumor uptake at early time points, which suggests it is a promising agent for EphB4-targeted imaging.
Assuntos
Anticorpos Monoclonais/imunologia , Neoplasias/diagnóstico , Neoplasias/imunologia , Receptor EphB4/imunologia , Linhagem Celular Tumoral , Diagnóstico por Imagem/métodos , Células HT29 , Humanos , Distribuição Tecidual/imunologiaRESUMO
IL-9 was first described in the late 1980s as a member of a growing number of cytokines that had pleiotropic functions in the immune system. Although many biological functions have been attributed to IL-9, it remains an understudied cytokine. A resurgence of interest in IL-9 has been spurred by recent work demonstrating a role for IL-9 in regulating inflammatory immunity and defining the transcription factors that activate the Il9 gene in cells that most efficiently produce IL-9. In this review, we summarize the characterization of IL-9 biological activities, highlight roles for the cytokine that are clearly defined, and outline questions regarding IL-9 functions that still require further exploration.