RESUMEN
Type 1 diabetes results from the autoimmune destruction of pancreatic insulin-producing ß-cells, primarily targeted by autoreactive T cells that recognize insulin B9-23 peptides as antigens. Using drift tube ion mobility spectrometry-mass spectrometry, transmission electron microscopy, and two-dimensional infrared spectroscopy, we characterized mouse insulin 1 B9-23 (Ins1 B9-23), insulin 2 B9-23 (Ins2 B9-23), along with two of their mutants, Ins2 B9-23 Y16A and Ins2 B9-23 C19S. Our findings indicate that Ins1 B9-23 and the Ins2 Y16A mutant exhibit rapid fibril formation, whereas Ins2 B9-23 and the Ins2 C19S mutant show slower fibrillization and a structural rearrangement from globular protofibrils to fibrillar aggregates. These differences in aggregation behaviors also manifest in interactions with (-)epigallocatechin gallate (EGCG), a canonical amyloid inhibitor. EGCG effectively disrupts the fibrils formed by Ins1 B9-23 and the Y16A mutant. However, it proves ineffective in preventing fibril formation of Ins2 B9-23 and the C19S mutant. These results establish a strong correlation between the aggregation behaviors of these peptides and their divergent effects on anti-islet autoimmunity.
Asunto(s)
Insulina , Fragmentos de Péptidos , Animales , Ratones , Insulina/química , Insulina/metabolismo , Fragmentos de Péptidos/química , Fragmentos de Péptidos/metabolismo , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/inmunología , Catequina/análogos & derivados , Catequina/química , Catequina/farmacología , Catequina/metabolismo , Amiloide/química , Amiloide/metabolismoRESUMEN
Objective: To analyze the clinical characteristics, treatment, and outcomes of children with complete left bundle branch block (CLBBB) mediated by maternal autoantibodies. Methods: A retrospective analysis was conducted on nine children diagnosed with maternal autoantibody-mediated CLBBB, treated at Beijing Anzhen Hospital and Fujian Provincial Hospital from March 2015 to August 2023. Their clinical characteristics, electrocardiographic and echocardiographic findings before and after treatment were reviewed. Paired sample t-test was used for inter-group comparison. Results: Among the mothers, 6 had positive antinuclear antibodies (ANA), 5 had anti-Sjogren syndrome antigen A antibodies, and 3 had anti-Ro-52 antibodies. The cohort included one female and eight male children, diagnosed with CLBBB at the age of 1 (2, 13) months. The positive autoantibodies in the infants, consisted with maternal antibodies, were detected within the first 3 months of life among 3 cases. Treatments included anti-heart failure therapy, myocardial nutritional support, intravenous immunoglobulin (IVIG) and glucocorticoids. Before treatment, the levels of troponin I (0.175 (0.060, 10.270) µg/L) and N-terminal pro-B-type natriuretic peptide (420 (327, 12 865) ng/L) were elevated, which normalized in most cases after treatment. Post-treatment, the QRS duration significantly shortened compared to pre-treatment ((137±15) vs.(169±25) ms, t=3.76, P<0.001), and the QTc interval significantly decreased ((433±41) vs. (514±27) ms, t=4.95, P=0.001). Before treatment, varying degrees of mitral and tricuspid regurgitation and marked interventricular septal dyskinesia were observed in echocardiography. After treatment, valve regurgitation and ventricular septum motion significantly improved, with a marked increase in left ventricular ejection fraction ((51±13)% vs. (27±6)%, t=-6.66, P<0.001). Conclusions: Maternal autoantibody-mediated CLBBB in children presents with chronic heart failure in infancy. Early treatment with anti-heart failure medications, IVIG and glucocorticoids can improve clinical symptoms.
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Anticuerpos Antinucleares , Autoanticuerpos , Bloqueo de Rama , Electrocardiografía , Humanos , Femenino , Estudios Retrospectivos , Masculino , Autoanticuerpos/sangre , Anticuerpos Antinucleares/sangre , Lactante , Ecocardiografía , Inmunoglobulinas Intravenosas/uso terapéutico , Péptido Natriurético Encefálico/sangre , Troponina I/sangre , Glucocorticoides/uso terapéutico , Fragmentos de Péptidos/inmunología , MadresRESUMEN
Precisely co-delivering antigens and immunosuppressants via nano/microcarriers to antigen-presenting cells (APCs) to induce antigen-specific immune tolerance represents a highly promising strategy for treating or preventing autoimmune diseases. The physicochemical properties of nano/microcarriers play a pivotal role in regulating immune function, with particle size and surface charge emerging as crucial parameters. In particular, very few studies have investigated micron-scale carriers of antigens. Herein, various nanoparticles and microparticles (NPs/MPs) with diverse particle sizes (ranging from 200 nm to 5 µm) and surface charges were prepared. Antigen peptides (MOG35-55) and immunosuppressants were encapsulated in these particles to induce antigen-specific immune tolerance. Two emulsifiers, PVA and PEMA, were employed to confer different surface charges to the NPs/MPs. The in vitro and in vivo studies demonstrated that NP/MP-PEMA could induce immune tolerance earlier than NP/MP-PVA and that NP/MP-PVA could induce immune tolerance more slowly and sustainably, indicating that highly negatively charged particles can induce immune tolerance more rapidly. Among the different sizes and charged particles tested, 200-nm-NP-PVA and 3-µm-MP-PEMA induced the greatest immune tolerance. In addition, the combination of NPs with MPs can further improve the induction of immune tolerance. In particular, combining 200 nm-NP-PVA with 3 µm-MP-PEMA or combining 500 nm-NP-PEMA with 3 µm-MP-PVA had optimal therapeutic efficacy. This study offers a new perspective for treating diseases by combining NPs with MPs and applying different emulsifiers to prepare NPs and MPs.
Asunto(s)
Tolerancia Inmunológica , Ratones Endogámicos C57BL , Nanopartículas , Tamaño de la Partícula , Animales , Tolerancia Inmunológica/efectos de los fármacos , Nanopartículas/química , Nanopartículas/administración & dosificación , Inmunosupresores/administración & dosificación , Inmunosupresores/química , Inmunosupresores/farmacología , Antígenos/administración & dosificación , Antígenos/inmunología , Femenino , Ratones , Portadores de Fármacos/química , Alcohol Polivinílico/química , Células Presentadoras de Antígenos/inmunología , Fragmentos de Péptidos/inmunología , Fragmentos de Péptidos/administración & dosificación , Fragmentos de Péptidos/químicaRESUMEN
BACKGROUND: Procollagen type III N-terminal peptide (P-III-NP) is a fibrosis biomarker associated with liver and cardiac fibrosis. Despite the value of P-III-NP as a biomarker, its analysis currently relies on enzyme-linked immunosorbent assays (ELISA) and radioimmunoassays (RIA), which require more than 3 h. To facilitate early diagnosis and treatment through rapid biomarker testing, we developed a one-step immunoassay for P-III-NP using a quenchbody, which is a fluorescence-labeled immunosensor for immediate signal generation. RESULTS: To create quenchbodies, the total mRNA of P-III-NP antibodies was extracted from early-developed hybridoma cells, and genes of variable regions were obtained through cDNA synthesis, inverse PCR, and sequencing. A single-chain variable fragment (scFv) with an N-terminal Cys-tag was expressed in E. coli Shuffle T7, resulting in a final yield of 9.8 mg L-1. The fluorescent dye was labeled on the Cys-tag of the anti-P-III-NP scFv using maleimide-thiol click chemistry, and the spacer arm lengths between the maleimide-fluorescent dyes were compared. Consequently, a TAMRA-C6-labeled quenchbody exhibited antigen-dependent fluorescence signals and demonstrated its ability to detect P-III-NP at concentrations as low as 0.46 ng mL-1 for buffer samples, 1.0 ng mL-1 for 2 % human serum samples. SIGNIFICANCE: This one-step P-III-NP detection method provides both qualitative and quantitative outcomes within a concise 5-min timeframe. Furthermore, its application can be expanded using a 96-well platform and human serum, making it a high-throughput and sensitive method for testing fibrotic biomarkers.
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Biomarcadores , Fibrosis , Colorantes Fluorescentes , Fragmentos de Péptidos , Procolágeno , Biomarcadores/sangre , Biomarcadores/análisis , Humanos , Colorantes Fluorescentes/química , Procolágeno/sangre , Procolágeno/química , Fragmentos de Péptidos/química , Fragmentos de Péptidos/inmunología , Anticuerpos de Cadena Única/química , Anticuerpos de Cadena Única/inmunología , Técnicas Biosensibles , Inmunoensayo/métodosRESUMEN
The original etiology of Alzheimer's disease (AD) is the deposition of amyloid-beta (Aß) proteins, which starts from the aggregation of the Aß oligomers. The optimal therapeutic strategy targeting Aß oligomer aggregation is the development of AD vaccines. Despite the fact that positive progress has been made for experimental attempts at AD vaccines, the physicochemical and even structural properties of these AD vaccines remain unclear. In this study, through immunoinformatic and molecular dynamics (MD) simulations, we first designed and simulated an alternative of vaccine TAPAS and found that the structure of the alternative can reproduce the 3D conformation of TAPAS determined experimentally. Meanwhile, immunoinformatic methods were used to analyze the physicochemical properties of TAPAS, including immunogenicity, antigenicity, thermal stability, and solubility, which confirm well the efficacy and safety of the vaccine, and validate the scheme reliability of immunoinformatic and MD simulations in designing and simulating the TAPAS vaccine. Using the same scheme, we predicted the 3D conformation of the optimized ACI-24 peptide vaccine, an Aß peptide with the first 15 residues of Aß42 (Aß1-15). The vaccine was verified once to be effective against both full-length Aß1-42 and truncated Aß4-42 aggregates, but an experimental 3D structure was absent. We have also explored the immune mechanism of the vaccine at the molecular level and found that the optimized ACI-24 and its analogues can block the growth of either full-length Aß1-42 or truncated Aß4-42 pentamer by contacting the hydrophobic residues within the N-terminus and ß1 region on the contact surface of either pentamer. Additionally, residues (D1, D7, S8, H13, and Q15) were identified as the key residues of the vaccine to contact either of the two Aß oligomers. This work provides a feasible implementation scheme of immunoinformatic and MD simulations for the development of AD small peptide vaccines, validating the power of the scheme as a parallel tool to the experimental approaches and injecting molecular-level information into the understanding and design of anti-AD vaccines.
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Vacunas contra el Alzheimer , Péptidos beta-Amiloides , Fragmentos de Péptidos , Vacunas de Subunidades Proteicas , Humanos , Enfermedad de Alzheimer/prevención & control , Vacunas contra el Alzheimer/química , Vacunas contra el Alzheimer/inmunología , Péptidos beta-Amiloides/química , Péptidos beta-Amiloides/inmunología , Simulación de Dinámica Molecular , Fragmentos de Péptidos/química , Fragmentos de Péptidos/inmunología , Conformación Proteica , Vacunas de Subunidades Proteicas/química , Vacunas de Subunidades Proteicas/inmunologíaRESUMEN
We have previously performed preclinical studies with the oxidized mannan-conjugated peptide MOG35-55 (OM-MOG35-55) in vivo (EAE mouse model) and in vitro (human peripheral blood) and demonstrated that OM-MOG35-55 suppresses antigen-specific T cell responses associated with autoimmune demyelination. Based on these results, we developed different types of dendritic cells (DCs) from the peripheral blood monocytes of patients with multiple sclerosis (MS) or healthy controls presenting OM-MOG35-55 or MOG-35-55 to autologous T cells to investigate the tolerogenic potential of OM-MOG35-55 for its possible use in MS therapy. To this end, monocytes were differentiated into different DC types in the presence of IL-4+GM-CSF ± dexamethasone (DEXA) ± vitamin D3 (VITD3). At the end of their differentiation, the DCs were loaded with peptides and co-cultured with T cells +IL-2 for 4 antigen presentation cycles. The phenotypes of the DC and T cell populations were analyzed using flow cytometry and the secreted cytokines using flow cytometry or ELISA. On day 8, the monocytes had converted into DCs expressing the typical markers of mature or immature phenotypes. Co-culture of T cells with all DC types for 4 antigen presentation cycles resulted in an increase in memory CD4+ T cells compared to memory CD8+ T cells and a suppressive shift in secreted cytokines, mainly due to increased TGF-ß1 levels. The best tolerogenic effect was obtained when patient CD4+ T cells were co-cultured with VITD3-DCs presenting OM-MOG35-55, resulting in the highest levels of CD4+PD-1+ T cells and CD4+CD25+Foxp3+ Τ cells. In conclusion, the tolerance induction protocols presented in this work demonstrate that OM-MOG35-55 could form the basis for the development of personalized therapeutic vaccines or immunomodulatory treatments for MS.
Asunto(s)
Células Dendríticas , Tolerancia Inmunológica , Esclerosis Múltiple , Glicoproteína Mielina-Oligodendrócito , Humanos , Glicoproteína Mielina-Oligodendrócito/inmunología , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Esclerosis Múltiple/inmunología , Esclerosis Múltiple/terapia , Esclerosis Múltiple/tratamiento farmacológico , Tolerancia Inmunológica/efectos de los fármacos , Fragmentos de Péptidos/inmunología , Fragmentos de Péptidos/farmacología , Adulto , Femenino , Mananos/farmacología , Masculino , Diferenciación Celular/efectos de los fármacos , Monocitos/inmunología , Monocitos/metabolismo , Linfocitos T/inmunología , Linfocitos T/metabolismo , Células Cultivadas , Persona de Mediana Edad , Linfocitos T CD4-Positivos/inmunología , Linfocitos T CD4-Positivos/metabolismo , Citocinas/metabolismoRESUMEN
The conventional inactivated tetanus toxin plays an instrumental role in preventing tetanus. Nevertheless, the challenges associated with its production process, the potential for adverse reactions, and reduced effectiveness in vulnerable populations such as neonates and the elderly rise the need for a novel tetanus toxin vaccine. Recombinant subunit vaccine offer a viable solution, and the tetanus toxin fragment C (TTFC) is emerging as a promising candidate. In this study, through spontaneous isopeptide bond formation we conjugated the recombinant TTFC to self-assembled mi3 nanoparticle, which derived from an optimized KDPG aldolase, and generated the TTFC-mi3 protein nanoparticle vaccine. We found that TTFC-mi3 is stable, uniform spherical nanoparticles. Comparing with the free TTFC alone, TTFC-mi3 enhances the uptake and subsequent activation of dendric cells (DCs). In addition, a single dose of adjuvant-free TTFC-mi3 elicited a more rapid and potent protective immunity in mice. Moreover, TTFC-mi3 is of favorable safety in vitro and in vivo. Our findings indicate that TTFC-mi3 is a rapid-response, non-aluminum-adjuvanted vaccine against tetanus.
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Nanovacunas , Toxina Tetánica , Toxoide Tetánico , Tétanos , Animales , Femenino , Ratones , Anticuerpos Antibacterianos/sangre , Anticuerpos Antibacterianos/inmunología , Ratones Endogámicos BALB C , Nanopartículas/química , Nanovacunas/administración & dosificación , Nanovacunas/inmunología , Fragmentos de Péptidos/inmunología , Fragmentos de Péptidos/administración & dosificación , Tétanos/prevención & control , Tétanos/inmunología , Toxina Tetánica/inmunología , Toxina Tetánica/genética , Toxoide Tetánico/inmunología , Toxoide Tetánico/administración & dosificación , Vacunas de Subunidad/inmunología , Vacunas de Subunidad/administración & dosificación , Vacunas Sintéticas/inmunología , Vacunas Sintéticas/administración & dosificaciónRESUMEN
Infections may affect the course of autoimmune inflammatory diseases of the central nervous system (CNS), such as multiple sclerosis (MS). Infections with lactate dehydrogenase-elevating virus (LDV) protected mice from developing experimental autoimmune encephalomyelitis (EAE), a mouse counterpart of MS. Uninfected C57BL/6 mice immunized with the myelin oligodendrocyte glycoprotein peptide (MOG35-55) experienced paralysis and lost weight at a greater rate than mice who had previously been infected with LDV. LDV infection decreased the presentation of the MOG peptide by CD11b+CD11c+ dendritic cells (DC) to pathogenic T lymphocytes. When comparing non-infected mice to infected mice, the histopathological examination of the CNS showed more areas of demyelination and CD45+ and CD3+, but not Iba1+ cell infiltration. These results suggest that the protective effect of LDV infection against EAE development is mediated by a suppression of myelin antigen presentation by a specific DC subset to autoreactive T lymphocytes. Such a mechanism might contribute to the general suppressive effect of infections on autoimmune diseases known as the hygiene hypothesis.
Asunto(s)
Células Dendríticas , Encefalomielitis Autoinmune Experimental , Virus Elevador de Lactato Deshidrogenasa , Esclerosis Múltiple , Glicoproteína Mielina-Oligodendrócito , Animales , Femenino , Ratones , Presentación de Antígeno/inmunología , Infecciones por Cardiovirus/inmunología , Antígeno CD11b/metabolismo , Antígeno CD11b/inmunología , Antígeno CD11c/metabolismo , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Modelos Animales de Enfermedad , Encefalomielitis Autoinmune Experimental/inmunología , Encefalomielitis Autoinmune Experimental/patología , Encefalomielitis Autoinmune Experimental/virología , Virus Elevador de Lactato Deshidrogenasa/inmunología , Ratones Endogámicos C57BL , Esclerosis Múltiple/inmunología , Esclerosis Múltiple/virología , Esclerosis Múltiple/patología , Glicoproteína Mielina-Oligodendrócito/inmunología , Fragmentos de Péptidos/inmunología , Linfocitos T/inmunología , Linfocitos T/metabolismoRESUMEN
Sensitive, accurate, and straightforward biosensors are pivotal in the battle against Alzheimer's disease, particularly in light of the escalating patient population. These biosensors enable early adjunctive diagnosis, thereby facilitating prompt intervention, alleviating socioeconomic burdens, and preserving individual well-being. In this study, we introduce the development of a highly sensitive add-drop dual-microring resonant microfluidic sensing chip boasting a sensitivity of 188.11 nm/RIU, marking a significant 20.7% enhancement over single microring systems. Leveraging ultra-thin Parylene C for streamlined antibody immobilization and non-destructive removal, this platform facilitates the precise quantification of the Alzheimer's disease biomarker Aß42. Employing an immune sensing strategy that amplifies and captures antigen signals using Au-labeled antibodies, we achieve an exceptional limit of detection of 9.02 pg/mL. The designed microring-based microfluidic biosensor chip exhibits outstanding specificity and sensitivity for Aß42 in serum samples, offering a promising avenue for the early adjunctive diagnosis of Alzheimer's disease.
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Péptidos beta-Amiloides , Técnicas Biosensibles , Fragmentos de Péptidos , Péptidos beta-Amiloides/análisis , Péptidos beta-Amiloides/sangre , Técnicas Biosensibles/métodos , Humanos , Fragmentos de Péptidos/sangre , Fragmentos de Péptidos/análisis , Fragmentos de Péptidos/inmunología , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/sangre , Límite de Detección , Dispositivos Laboratorio en un Chip , Técnicas Analíticas Microfluídicas/instrumentación , Técnicas Analíticas Microfluídicas/métodos , Anticuerpos Inmovilizados/inmunología , Anticuerpos Inmovilizados/química , Oro/químicaRESUMEN
Microbial organisms have key roles in numerous physiological processes in the human body and have recently been shown to modify the response to immune checkpoint inhibitors1,2. Here we aim to address the role of microbial organisms and their potential role in immune reactivity against glioblastoma. We demonstrate that HLA molecules of both glioblastoma tissues and tumour cell lines present bacteria-specific peptides. This finding prompted us to examine whether tumour-infiltrating lymphocytes (TILs) recognize tumour-derived bacterial peptides. Bacterial peptides eluted from HLA class II molecules are recognized by TILs, albeit very weakly. Using an unbiased antigen discovery approach to probe the specificity of a TIL CD4+ T cell clone, we show that it recognizes a broad spectrum of peptides from pathogenic bacteria, commensal gut microbiota and also glioblastoma-related tumour antigens. These peptides were also strongly stimulatory for bulk TILs and peripheral blood memory cells, which then respond to tumour-derived target peptides. Our data hint at how bacterial pathogens and bacterial gut microbiota can be involved in specific immune recognition of tumour antigens. The unbiased identification of microbial target antigens for TILs holds promise for future personalized tumour vaccination approaches.
Asunto(s)
Antígenos de Neoplasias , Bacterias , Proteínas Bacterianas , Glioblastoma , Linfocitos Infiltrantes de Tumor , Fragmentos de Péptidos , Humanos , Antígenos de Neoplasias/inmunología , Proteínas Bacterianas/inmunología , Vacunas contra el Cáncer/inmunología , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/inmunología , Línea Celular Tumoral , Microbioma Gastrointestinal/inmunología , Glioblastoma/inmunología , Glioblastoma/patología , Antígenos de Histocompatibilidad Clase II/inmunología , Antígenos HLA/inmunología , Linfocitos Infiltrantes de Tumor/citología , Linfocitos Infiltrantes de Tumor/inmunología , Fragmentos de Péptidos/inmunología , Simbiosis , Bacterias/inmunología , Bacterias/patogenicidadRESUMEN
Numerous publications have underlined the link between complement C5a and the clinical course of COVID-19. We previously reported that levels of C5a remain high in the group of severely ill patients up to 90 days after hospital discharge. We have now evaluated which complement pathway fuels the elevated levels of C5a during hospitalization and follow-up. The alternative pathway (AP) activation marker C3bBbP and the soluble fraction of C4d, a footprint of the classical/lectin (CP/LP) pathway, were assessed by immunoenzymatic assay in a total of 188 serial samples from 49 patients infected with SARS-CoV-2. Unlike C5a, neither C3bBbP nor C4d readouts rose proportionally to the severity of the disease. Detailed correlation analyses in hospitalization and follow-up samples collected from patients of different disease severity showed significant positive correlations of AP and CP/LP markers with C5a in certain groups, except for the follow-up samples of the patients who suffered from highly severe COVID-19 and presented the highest C5a readouts. In conclusion, there is not a clear link between persistently high levels of C5a after hospital discharge and markers of upstream complement activation, suggesting the existence of a non-canonical source of C5a in patients with a severe course of COVID-19.
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COVID-19 , Activación de Complemento , Complemento C3b , Complemento C4b , Complemento C5a , Factor B del Complemento , Fragmentos de Péptidos , Biomarcadores/sangre , COVID-19/sangre , COVID-19/inmunología , Activación de Complemento/inmunología , Complemento C3b/inmunología , Complemento C4b/inmunología , Complemento C5a/análisis , Complemento C5a/inmunología , Factor B del Complemento/inmunología , Proteínas del Sistema Complemento/inmunología , Humanos , Fragmentos de Péptidos/inmunología , SARS-CoV-2RESUMEN
Indoleamine 2,3-dioxygenase 1 (IDO1) and tryptophan 2,3-dioxygenase (TDO) are key enzymes for tryptophan degradation, regulating immune tolerance during pregnancy. The intrauterine renin-angiotensin system is also involved in the progression of a healthy pregnancy. Angiotensin(1-7) maintains the integrity of fetal membranes via counteracting the pro-inflammatory actions of Angiotensin II. No data are available on placental Angiotensin(1-7) co-expression with TDO. We aimed to characterize TDO mRNA expression and its localization in different areas of the placenta of physiological pregnancies delivered at term; its co-expression with Angiotensin(1-7) and its correlation with the plasma kynurenine/tryptophan (Kyn/Trp) ratio was investigated. This prospective observational study included a nonconsecutive series of 20 singleton uncomplicated pregnancies delivered vaginally. TDO mRNA was expressed in both maternal and fetal sides of the placentas and TDO protein also in the villi and it was co-expressed with IDO1 in almost half of the placental cells at these sites. The percentage of TDO+ and IDO1+ cells appeared to be influenced by maternal pre-gestational smoking and newborn weight. A strong correlation was found between the percentage of TDO+ and IDO1+ cells in the villi. TDO+ cells also expressed Angiotensin(1-7), with a higher percentage on the fetal side and in the villi compared to the maternal one. Kyn/Trp plasma ratio was not correlated with IDO and TDO expression nor with the patient's characteristics. Collectively, our data indicate that TDO is detectable in placental tissue and is co-expressed with IDO and with Angiotensin(1-7)+ on the fetal side and in the villi.
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Angiotensina I , Tolerancia Inmunológica , Indolamina-Pirrol 2,3,-Dioxigenasa , Fragmentos de Péptidos , Placenta , Triptófano Hidroxilasa , Angiotensina I/genética , Angiotensina I/inmunología , Angiotensina II/inmunología , Femenino , Humanos , Tolerancia Inmunológica/genética , Tolerancia Inmunológica/inmunología , Indolamina-Pirrol 2,3,-Dioxigenasa/biosíntesis , Indolamina-Pirrol 2,3,-Dioxigenasa/genética , Indolamina-Pirrol 2,3,-Dioxigenasa/inmunología , Recién Nacido , Quinurenina/análisis , Quinurenina/genética , Quinurenina/inmunología , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/inmunología , Placenta/enzimología , Placenta/inmunología , Embarazo , ARN Mensajero , Triptófano/análisis , Triptófano/genética , Triptófano/inmunología , Triptófano Hidroxilasa/genética , Triptófano Hidroxilasa/inmunología , Triptófano Oxigenasa/genética , Triptófano Oxigenasa/inmunologíaRESUMEN
Gastrointestinal health depends on the adaptive immune system tolerating the foreign proteins in food1,2. This tolerance is paradoxical because the immune system normally attacks foreign substances by generating inflammation. Here we addressed this conundrum by using a sensitive cell enrichment method to show that polyclonal CD4+ T cells responded to food peptides, including a natural one from gliadin, by proliferating weakly in secondary lymphoid organs of the gut-liver axis owing to the action of regulatory T cells. A few food-specific T cells then differentiated into T follicular helper cells that promoted a weak antibody response. Most cells in the expanded population, however, lacked canonical T helper lineage markers and fell into five subsets dominated by naive-like or T follicular helper-like anergic cells with limited capacity to form inflammatory T helper 1 cells. Eventually, many of the T helper lineage-negative cells became regulatory T cells themselves through an interleukin-2-dependent mechanism. Our results indicate that exposure to food antigens causes cognate CD4+ naive T cells to form a complex set of noncanonical hyporesponsive T helper cell subsets that lack the inflammatory functions needed to cause gut pathology and yet have the potential to produce regulatory T cells that may suppress it.
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Linfocitos T CD4-Positivos , Alimentos , Tolerancia Inmunológica , Alérgenos/inmunología , Formación de Anticuerpos , Linfocitos T CD4-Positivos/citología , Linfocitos T CD4-Positivos/inmunología , Proteínas en la Dieta/inmunología , Tracto Gastrointestinal/citología , Tracto Gastrointestinal/inmunología , Gliadina/inmunología , Tolerancia Inmunológica/inmunología , Inflamación , Interleucina-2/inmunología , Hígado/citología , Hígado/inmunología , Tejido Linfoide/citología , Tejido Linfoide/inmunología , Fragmentos de Péptidos/inmunología , Células T Auxiliares Foliculares/citología , Células T Auxiliares Foliculares/inmunología , Linfocitos T Reguladores/citología , Linfocitos T Reguladores/inmunología , Células TH1/citología , Células TH1/inmunologíaRESUMEN
BACKGROUND: Plasmodium vivax is emerging as the dominant and prevalent species causing malaria in near-elimination settings outside of Africa. Hypnozoites, the dormant liver stage parasite of P. vivax, are undetectable to any currently available diagnostic test, yet are a major reservoir for transmission. Advances have been made to harness the naturally acquired immune response to identify recent exposure to P. vivax blood-stage parasites and, therefore, infer the presence of hypnozoites. This in-development diagnostic is currently able to detect infections within the last 9-months with 80% sensitivity and 80% specificity. Further work is required to optimize protein expression and protein constructs used for antibody detection. METHODS: The antibody response against the top performing predictor of recent infection, P. vivax reticulocyte binding protein 2b (PvRBP2b), was tested against multiple fragments of different sizes and from different expression systems. The IgG induced against the recombinant PvRBP2b fragments in P. vivax infected individuals was measured at the time of infection and in a year-long observational cohort; both conducted in Thailand. RESULTS: The antibody responses to some but not all different sized fragments of PvRBP2b protein are highly correlated with each other, significantly higher 1-week post-P. vivax infection, and show potential for use as predictors of recent P. vivax infection. CONCLUSIONS: To achieve P. vivax elimination goals, novel diagnostics are required to aid in detection of hidden parasite reservoirs. PvRBP2b was previously shown to be the top candidate for single-antigen classification of recent P. vivax exposure and here, it is concluded that several alternative recombinant PvRBP2b fragments can achieve equal sensitivity and specificity at predicting recent P. vivax exposure.
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Inmunoglobulina G , Malaria Vivax , Proteínas de la Membrana , Plasmodium vivax , Proteínas Protozoarias , Anticuerpos Antiprotozoarios/metabolismo , Formación de Anticuerpos , Humanos , Inmunoglobulina G/metabolismo , Malaria Vivax/parasitología , Proteínas de la Membrana/inmunología , Fragmentos de Péptidos/inmunología , Proteínas Protozoarias/inmunología , Proteínas Protozoarias/metabolismo , Reticulocitos/metabolismoRESUMEN
Immune evasion is indispensable for cancer initiation and progression, although its underlying mechanisms in pancreatic ductal adenocarcinoma (PDAC) are not fully known. Here, we characterize the function of tumor-derived PGRN in promoting immune evasion in primary PDAC. Tumor- but not macrophage-derived PGRN is associated with poor overall survival in PDAC. Multiplex immunohistochemistry shows low MHC class I (MHCI) expression and lack of CD8+ T cell infiltration in PGRN-high tumors. Inhibition of PGRN abrogates autophagy-dependent MHCI degradation and restores MHCI expression on PDAC cells. Antibody-based blockade of PGRN in a PDAC mouse model remarkably decelerates tumor initiation and progression. Notably, tumors expressing LCMV-gp33 as a model antigen are sensitized to gp33-TCR transgenic T cell-mediated cytotoxicity upon PGRN blockade. Overall, our study shows a crucial function of tumor-derived PGRN in regulating immunogenicity of primary PDAC.
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Adenocarcinoma/genética , Carcinoma Ductal Pancreático/genética , Antígenos de Histocompatibilidad Clase I/genética , Neoplasias Pancreáticas/genética , Progranulinas/genética , Escape del Tumor/genética , Adenocarcinoma/inmunología , Adenocarcinoma/mortalidad , Adenocarcinoma/terapia , Animales , Anticuerpos Neutralizantes/farmacología , Antígenos Virales/genética , Antígenos Virales/inmunología , Autofagia/efectos de los fármacos , Autofagia/genética , Autofagia/inmunología , Linfocitos T CD8-positivos/efectos de los fármacos , Linfocitos T CD8-positivos/inmunología , Linfocitos T CD8-positivos/patología , Carcinoma Ductal Pancreático/inmunología , Carcinoma Ductal Pancreático/mortalidad , Carcinoma Ductal Pancreático/terapia , Línea Celular Tumoral , Movimiento Celular/efectos de los fármacos , Estudios de Cohortes , Citotoxicidad Inmunológica , Expresión Génica , Glicoproteínas/genética , Glicoproteínas/inmunología , Antígenos de Histocompatibilidad Clase I/inmunología , Humanos , Virus de la Coriomeningitis Linfocítica/genética , Virus de la Coriomeningitis Linfocítica/inmunología , Ratones , Neoplasias Pancreáticas/inmunología , Neoplasias Pancreáticas/mortalidad , Neoplasias Pancreáticas/terapia , Fragmentos de Péptidos/genética , Fragmentos de Péptidos/inmunología , Progranulinas/antagonistas & inhibidores , Progranulinas/inmunología , Proteolisis , Análisis de Supervivencia , Microambiente Tumoral/genética , Microambiente Tumoral/inmunología , Proteínas Virales/genética , Proteínas Virales/inmunología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
BACKGROUND: The GMZ2.6c malaria vaccine candidate is a multi-stage Plasmodium falciparum chimeric protein which contains a fragment of the sexual-stage Pfs48/45-6C protein genetically fused to GMZ2, a fusion protein of GLURP and MSP-3, that has been shown to be well tolerated, safe and immunogenic in clinical trials performed in a malaria-endemic area of Africa. However, there is no data available on the antigenicity or immunogenicity of GMZ2.6c in humans. Considering that circulating parasites can be genetically distinct in different malaria-endemic areas and that host genetic factors can influence the immune response to vaccine antigens, it is important to verify the antigenicity, immunogenicity and the possibility of associated protection in individuals living in malaria-endemic areas with different epidemiological scenarios. Herein, the profile of antibody response against GMZ2.6c and its components (MSP-3, GLURP and Pfs48/45) in residents of the Brazilian Amazon naturally exposed to malaria, in areas with different levels of transmission, was evaluated. METHODS: This study was performed using serum samples from 352 individuals from Cruzeiro do Sul and Mâncio Lima, in the state of Acre, and Guajará, in the state of Amazonas. Specific IgG, IgM, IgA and IgE antibodies and IgG subclasses were detected by Enzyme-Linked Immunosorbent Assay. RESULTS: The results showed that GMZ2.6c protein was widely recognized by naturally acquired antibodies from individuals of the Brazilian endemic areas with different levels of transmission. The higher prevalence of individuals with antibodies against GMZ2.6c when compared to its individual components may suggest an additive effect of GLURP, MSP-3, and Pfs48/45 when inserted in a same construct. Furthermore, naturally malaria-exposed individuals predominantly had IgG1 and IgG3 cytophilic anti-GMZ2.6c antibodies, an important fact considering that the acquisition of anti-malaria protective immunity results from a delicate balance between cytophilic/non-cytophilic antibodies. Interestingly, anti-GMZ2.6c antibodies seem to increase with exposure to malaria infection and may contribute to parasite immunity. CONCLUSIONS: The data showed that GMZ2.6c protein is widely recognized by naturally acquired antibodies from individuals living in malaria-endemic areas in Brazil and that these may contribute to parasite immunity. These data highlight the importance of GMZ2.6c as a candidate for an anti-malarial vaccine.
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Formación de Anticuerpos , Antígenos de Protozoos/inmunología , Vacunas contra la Malaria/inmunología , Glicoproteínas de Membrana/inmunología , Fragmentos de Péptidos/inmunología , Plasmodium falciparum/inmunología , Proteínas Protozoarias/inmunología , Adolescente , Adulto , Brasil , Femenino , Humanos , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
Aging is associated with functional deficits in the naive T cell compartment, which compromise the generation of de novo immune responses against previously unencountered Ags. The mechanisms that underlie this phenomenon have nonetheless remained unclear. We found that naive CD8+ T cells in elderly humans were prone to apoptosis and proliferated suboptimally in response to stimulation via the TCR. These abnormalities were associated with dysregulated lipid metabolism under homeostatic conditions and enhanced levels of basal activation. Importantly, reversal of the bioenergetic anomalies with lipid-altering drugs, such as rosiglitazone, almost completely restored the Ag responsiveness of naive CD8+ T cells. Interventions that favor lipid catabolism may therefore find utility as adjunctive therapies in the elderly to promote vaccine-induced immunity against targetable cancers and emerging pathogens, such as seasonal influenza viruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2).
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Envejecimiento/inmunología , Linfocitos T CD8-positivos/inmunología , Inmunocompetencia/efectos de los fármacos , Metabolismo de los Lípidos , Adulto , Anciano , Anciano de 80 o más Años , Apoptosis , Linfocitos T CD8-positivos/metabolismo , COVID-19/inmunología , Vacunas contra el Cáncer/inmunología , División Celular , Femenino , Fenofibrato/farmacología , Glucosa/metabolismo , Antígeno HLA-A2/inmunología , Humanos , Hipolipemiantes/farmacología , Hipolipemiantes/uso terapéutico , Gripe Humana/inmunología , Metabolismo de los Lípidos/efectos de los fármacos , Activación de Linfocitos , Antígeno MART-1/química , Antígeno MART-1/inmunología , Masculino , Persona de Mediana Edad , Neoplasias/inmunología , Fragmentos de Péptidos/inmunología , Rosiglitazona/farmacología , Método Simple Ciego , Vacunación , Vacunas Virales/inmunología , Adulto JovenRESUMEN
Safe and effective vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants are the best approach to successfully combat the COVID-19 pandemic. The receptor-binding domain (RBD) of the viral spike protein is a major target to develop candidate vaccines. α-Galactosylceramide (αGalCer), a potent invariant natural killer T cell (iNKT) agonist, was site-specifically conjugated to the N-terminus of the RBD to form an adjuvant-protein conjugate, which was anchored on the liposome surface. This is the first time that an iNKT cell agonist was conjugated to the protein antigen. Compared to the unconjugated RBD/αGalCer mixture, the αGalCer-RBD conjugate induced significantly stronger humoral and cellular responses. The conjugate vaccine also showed effective cross-neutralization to all variants of concern (B.1.1.7/alpha, B.1.351/beta, P.1/gamma, B.1.617.2/delta, and B.1.1.529/omicron). These results suggest that the self-adjuvanting αGalCer-RBD has great potential to be an effective COVID-19 vaccine candidate, and this strategy might be useful for designing various subunit vaccines.
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Vacunas contra la COVID-19/uso terapéutico , COVID-19/terapia , Galactosilceramidas/uso terapéutico , Fragmentos de Péptidos/uso terapéutico , SARS-CoV-2/inmunología , Vacunas Conjugadas/uso terapéutico , Adyuvantes Inmunológicos/química , Adyuvantes Inmunológicos/uso terapéutico , Animales , Anticuerpos Neutralizantes/inmunología , Anticuerpos Antivirales/inmunología , Vacunas contra la COVID-19/química , Vacunas contra la COVID-19/inmunología , Femenino , Galactosilceramidas/química , Galactosilceramidas/inmunología , Inmunidad Humoral/efectos de los fármacos , Inmunidad Innata/efectos de los fármacos , Interferón gamma/metabolismo , Liposomas/química , Liposomas/inmunología , Liposomas/uso terapéutico , Ratones Endogámicos BALB C , Fragmentos de Péptidos/química , Fragmentos de Péptidos/inmunología , Dominios Proteicos , Glicoproteína de la Espiga del Coronavirus/química , Glicoproteína de la Espiga del Coronavirus/inmunología , Glicoproteína de la Espiga del Coronavirus/uso terapéutico , Vacunas Conjugadas/química , Vacunas Conjugadas/inmunologíaRESUMEN
BACKGROUND: Complement activation plays an important pathogenic role in numerous diseases. The ratio between an activation product and its parent protein is suggested to be more sensitive to detect complement activation than the activation product itself. In the present study we explored whether the ratio between the activation product and the parent protein for C3 (C3bc/C3) and for C5 (sC5b-9/C5) increased the sensitivity to detect complement activation in acute clinical settings compared to the activation product alone. MATERIALS AND METHODS: Samples from patients with acute heart failure following ST-elevated myocardial infarction (STEMI) and from patients with out-of-hospital cardiac arrest (OHCA) were used. C3, C3bc and C5, sC5b-9 were analysed in 629 and 672 patient samples, respectively. Healthy controls (n = 20) served to determine reference cut-off values for activation products and ratios, defined as two SD above the mean. RESULTS: Increased C3bc/C3- and sC5b-9/C5 ratios were vastly dependent on C3bc and sC5b-9. Thus, 99.5 % and 98.1 % of the increased C3bc/C3- and sC5b-9/C5 ratios were solely dependent on increased C3bc and sC5b-9, respectively. Significantly decreased C3 and C5 caused increased ratios in only 3/600 (0.5 %) and 4/319 (1.3 %) samples, respectively. Strong correlations between C3bc and C3bc/C3-ratio and between sC5b-9 and sC5b-9/C5-ratio were found in the STEMI- (r = 0.926 and r = 0.786, respectively) and the OHCA-population (r = 0.908 and r = 0.843, respectively; p < 0.0001 for all). Importantly, sC5b-9 identified worse outcome groups better than sC5b-9/C5-ratio. CONCLUSION: C3bc and sC5b-9 were sensitive markers of complement activation. The ratios of C3bc/C3 and sC5b-9/C5 did not improve detection of complement activation systemically.
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Activación de Complemento/inmunología , Complemento C3/inmunología , Complemento C3b/inmunología , Complemento C5/inmunología , Complejo de Ataque a Membrana del Sistema Complemento/inmunología , Fragmentos de Péptidos/inmunología , Adulto , Estudios de Casos y Controles , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
OBJECTIVE: To evaluate the role of autoantibodies to N-terminally truncated glutamic acid decarboxylase GAD65(96-585) (t-GADA) as a marker for type 1 diabetes (T1D) and to assess the potential human leukocyte antigen (HLA) associations with such autoantibodies. DESIGN: In this cross-sectional study combining data from the Finnish Pediatric Diabetes Register, the Type 1 Diabetes Prediction and Prevention study, the DIABIMMUNE study, and the Early Dietary Intervention and Later Signs of Beta-Cell Autoimmunity study, venous blood samples from 760 individuals (53.7% males) were analyzed for t-GADA, autoantibodies to full-length GAD65 (f-GADA), and islet cell antibodies. Epitope-specific GAD autoantibodies were analyzed from 189 study participants. RESULTS: T1D had been diagnosed in 174 (23%) participants. Altogether 631 (83%) individuals tested positive for f-GADA and 451 (59%) for t-GADA at a median age of 9.0 (range 0.2-61.5) years. t-GADA demonstrated higher specificity (46%) and positive predictive value (30%) for T1D than positivity for f-GADA alone (15% and 21%, respectively). Among participants positive for f-GADA, those who tested positive for t-GADA carried more frequently HLA genotypes conferring increased risk for T1D than those who tested negative for t-GADA (77% vs 53%; P < 0.001). CONCLUSIONS: Autoantibodies to N-terminally truncated GAD improve the screening for T1D compared to f-GADA and may facilitate the selection of participants for clinical trials. HLA class II-mediated antigen presentation of GAD(96-585)-derived or structurally similar peptides might comprise an important pathomechanism in T1D.