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Maturation of the secondary antibody repertoire requires class-switch recombination (CSR), which switches IgM to other immunoglobulins (Igs), and somatic hypermutation, which promotes the production of high-affinity antibodies. Following immune response or infection within the body, activation of T cell-dependent and T cell-independent antigens triggers the activation of activation-induced cytidine deaminase, initiating the CSR process. CSR has the capacity to modify the functional properties of antibodies, thereby contributing to the adaptive immune response in the organism. Ig CSR defects, characterized by an abnormal relative frequency of Ig isotypes, represent a rare form of primary immunodeficiency. Elucidating the molecular basis of Ig diversification is essential for a better understanding of diseases related to Ig CSR defects and could provide clues for clinical diagnosis and therapeutic approaches. Here, we review the most recent insights on the diversification of five Ig isotypes and choose several classic diseases, including hyper-IgM syndrome, Waldenström macroglobulinemia, hyper-IgD syndrome, selective IgA deficiency, hyper-IgE syndrome, multiple myeloma, and Burkitt lymphoma, to illustrate the mechanism of Ig CSR deficiency. The investigation into the underlying mechanism of Ig CSR holds significant potential for the advancement of increasingly precise diagnostic and therapeutic approaches.
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Allergy is a complex array of diseases influenced by innate and adaptive immunity, genetic polymorphisms, and environmental triggers. Atopic dermatitis (AD) is a chronic inflammatory skin disease characterized by barrier defects and immune dysregulation, sometimes leading to asthma and food allergies because of the atopic march. During atopic skin inflammation, Langerhans cells and dendritic cells (DCs) in the skin capture and deliver allergen information to local lymph nodes. DCs are essential immune sensors coordinating immune reactions by capturing and presenting antigens to T cells. In the context of allergic responses, DCs play a crucial role in instructing two types of helper T cells - type 2 helper T (Th2) cells and follicular helper T (TFH) cells - in allergic responses and IgE antibody responses. In skin sensitization, the differentiation and function of Th2 cells and TFH cells are influenced by skin-derived factors, including epithelial cytokines, chemokines, and signaling pathways to modify the function of migratory DCs and conventional DCs. In this review, we aim to understand the specific mechanisms involving DCs in allergic responses to provide insights into the pathogenesis of allergic diseases and potential therapeutic strategies.
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The mechanisms by which the number of memory CD8 T cells is stably maintained remains incompletely understood. It has been postulated that maintaining them requires help from CD4 T cells, because adoptively transferred memory CD8 T cells persist poorly in MHC class II (MHCII)-deficient mice. Here we show that chronic interferon-γ signals, not CD4 T cell-deficiency, are responsible for their attrition in MHCII-deficient environments. Excess IFN-γ is produced primarily by endogenous colonic CD8 T cells in MHCII-deficient mice. IFN-γ neutralization restores the number of memory CD8 T cells in MHCII-deficient mice, whereas repeated IFN-γ administration or transduction of a gain-of-function STAT1 mutant reduces their number in wild-type mice. CD127high memory cells proliferate actively in response to IFN-γ signals, but are more susceptible to attrition than CD127low terminally differentiated effector memory cells. Furthermore, single-cell RNA-sequencing of memory CD8 T cells reveals proliferating cells that resemble short-lived, terminal effector cells and documents global downregulation of gene signatures of long-lived memory cells in MHCII-deficient environments. We propose that chronic IFN-γ signals deplete memory CD8 T cells by compromising their long-term survival and by diverting self-renewing CD127high cells toward terminal differentiation.
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Linfocitos T CD4-Positivos , Linfocitos T CD8-positivos , Memoria Inmunológica , Interferón gamma , Factor de Transcripción STAT1 , Animales , Linfocitos T CD8-positivos/inmunología , Interferón gamma/metabolismo , Interferón gamma/inmunología , Linfocitos T CD4-Positivos/inmunología , Ratones , Factor de Transcripción STAT1/metabolismo , Factor de Transcripción STAT1/genética , Factor de Transcripción STAT1/deficiencia , Ratones Endogámicos C57BL , Antígenos de Histocompatibilidad Clase II/inmunología , Antígenos de Histocompatibilidad Clase II/genética , Antígenos de Histocompatibilidad Clase II/metabolismo , Transducción de Señal , Ratones Noqueados , Células T de Memoria/inmunología , Células T de Memoria/metabolismo , Subunidad alfa del Receptor de Interleucina-7/metabolismo , Proliferación Celular , Traslado AdoptivoRESUMEN
AIMS: To evaluate the correlation between C-peptide index (CPI) at 2 h post-meal and endogenous insulin secretory capacity and to develop clinical models to predict the possibility of withdrawal from insulin therapy in patients with type 2 diabetes. METHOD: This was a single-centre retrospective study of patients with type 2 diabetes admitted to our hospital. Patients were divided into a withdrawal group (n = 72) and a non-withdrawal group (n = 75) based on whether they were able to withdraw from insulin therapy at discharge, and the correlation between CPI at 2 h after meal and diabetes-related parameters was evaluated. In addition, we created two clinical models to predict the possibility of withdrawal from insulin therapy using machine learning. RESULTS: The glycated haemoglobin values of the study participants were 87.8 ± 22.6 mmol/mo. The CPI at 2 h post-meal was 1.93 ± 1.28 in the non-withdrawal group and 2.97 ± 2.07 in the withdrawal group (p < 0.001). CPI at 2 h post-meal was an independent predictor of withdrawal from insulin therapy. In addition, CPI at 2 h post-meal was a better predictor than fasting CPI. Six factors associated with insulin therapy withdrawal (age, duration of diabetes, creatinine, alanine aminotransferase, insulin therapy until hospitalization, and CPI at 2 h post-meal) were used to generate two clinical models by machine learning. The accuracy of the generated clinical models ranged from 78.3% to 82.6%. CONCLUSION: The CPI at 2 h post-meal is a clinically useful measure of endogenous insulin secretory capacity under non-fasting conditions.
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Péptido C , Diabetes Mellitus Tipo 2 , Hipoglucemiantes , Secreción de Insulina , Insulina , Periodo Posprandial , Humanos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/sangre , Masculino , Femenino , Persona de Mediana Edad , Estudios Retrospectivos , Péptido C/sangre , Insulina/uso terapéutico , Insulina/administración & dosificación , Anciano , Hipoglucemiantes/uso terapéutico , Hemoglobina Glucada/análisis , Hemoglobina Glucada/metabolismo , Privación de Tratamiento/estadística & datos numéricos , Aprendizaje Automático , ComidasRESUMEN
Signal-transducing adaptor protein (STAP)-1 is an adaptor protein that is widely expressed in T cells. In this article, we show that STAP-1 upregulates TCR-mediated T cell activation and T cell-mediated airway inflammation. Using STAP-1 knockout mice and STAP-1-overexpressing Jurkat cells, we found that STAP-1 enhanced TCR signaling, resulting in increased calcium mobilization, NFAT activity, and IL-2 production. Upon TCR engagement, STAP-1 binding to ITK promoted formation of ITK-LCK and ITK-phospholipase Cγ1 complexes to induce downstream signaling. Consistent with the results, STAP-1 deficiency reduced the severity of symptoms in experimental autoimmune encephalomyelitis. Single-cell RNA-sequencing analysis revealed that STAP-1 is essential for accumulation of T cells and Ifng and Il17 expression in spinal cords after experimental autoimmune encephalomyelitis induction. Th1 and Th17 development was also attenuated in STAP-1 knockout naive T cells. Taken together, STAP-1 enhances TCR signaling and plays a role in T cell-mediated immune disorders.
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Proteínas Adaptadoras Transductoras de Señales , Encefalomielitis Autoinmune Experimental , Inflamación , Animales , Ratones , Proteínas Adaptadoras Transductoras de Señales/genética , Inflamación/metabolismo , Inflamación/patología , Activación de Linfocitos , Receptores de Antígenos de Linfocitos T , Transducción de SeñalRESUMEN
Invariant natural killer T (iNKT) cells are innate-like T lymphocytes that express an invariant T cell receptor α chain and contribute to bridging innate and acquired immunity with rapid production of large amounts of cytokines after stimulation. Among effecter subsets of iNKT cells, follicular helper NKT (NKTFH) cells are specialized to help B cells. However, the mechanisms of NKTFH cell differentiation remain to be elucidated. In this report, we studied the mechanism of NKTFH cell differentiation induced by pneumococcal surface protein A and α-galactosylceramide (P/A) vaccination. We found that Gr-1+ cells helped iNKT cell proliferation and NKTFH cell differentiation in the spleen by producing interleukin-27 (IL-27) in the early phase after vaccination. The neutralization of IL-27 impaired NKTFH cell differentiation, which resulted in compromised antibody production and diminished protection against Streptococcus pneumoniae infection by the P/A vaccine. Our data indicated that Gr-1+ cell-derived IL-27 stimulated mitochondrial metabolism, meeting the energic demand required for iNKT cells to differentiate into NKTFH cells. Interestingly, Gr-1+ cell-derived IL-27 was induced by iNKT cells via interferon-γ production. Collectively, our findings suggest that optimizing the metabolism of iNKT cells was essential for acquiring specific effector functions, and they provide beneficial knowledge on iNKT cell-mediated vaccination-mediated therapeutic strategies.
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Interleucina-27 , Células T Asesinas Naturales , Animales , Ratones , Interleucina-27/metabolismo , Linfocitos T Colaboradores-Inductores , Citocinas/metabolismo , Diferenciación Celular , Ratones Endogámicos C57BLRESUMEN
Recently, the development of once-weekly incretin-based injections dulaglutide and semaglutide has drawn a great deal of attention. This study is aimed at comparing the efficacy of once-weekly GLP-1 receptor activator (GLP-1RA) dulaglutide and semaglutide on glycemic control and several metabolic parameters in patients with type 2 diabetes mellitus. We compared various clinical parameters between before and after switching from dulaglutide to semaglutide in "study 1" (pre-post comparison) and set the control group using propensity score matching method in "study 2." In "study 1," six months after the switching, HbA1c was significantly reduced from 8.2% to 7.6% and body mass index was also decreased from 30.4 kg/m2 to 30.0 kg/m2. Such effects were more pronounced in subjects whose glycemic control was poor. In "study 2," after 1 : 1 propensity score matching, glycemic control and body weight management were improved in the switching group compared with the dulaglutide continuation group. In this study including obese subjects with poor glycemic control, switching dulaglutide to semaglutide showed more beneficial effects on both glycemic and weight control irrespective of age, body weight, and diabetes duration. Therefore, we should bear in mind that it would be better to start using a relatively new once-weekly GLP-1RA semaglutide in clinical practice, especially in obese subjects with poor glycemic control with other GLP-1RAs.
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Diabetes Mellitus Tipo 2 , Péptidos Similares al Glucagón/análogos & derivados , Fragmentos Fc de Inmunoglobulinas , Proteínas Recombinantes de Fusión , Humanos , Diabetes Mellitus Tipo 2/tratamiento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Hipoglucemiantes/uso terapéutico , Agonistas Receptor de Péptidos Similares al Glucagón , Control Glucémico , Peso Corporal , Obesidad , Receptor del Péptido 1 Similar al Glucagón/agonistasRESUMEN
BACKGROUND: Basophils are rare but important effector cells in many allergic disorders. Contrary to their early progenitors, the terminal developmental processes of basophils in which they gain their unique functional properties are unknown. OBJECTIVE: We sought to identify a novel late-stage basophil precursor and a transcription factor regulating the terminal maturation of basophils. METHODS: Using flow cytometry, transcriptome analysis, and functional assays, we investigated the identification and functionality of the basophil precursors as well as basophil development. We generated mice with basophil-specific deletion of nuclear factor IL-3 (NFIL3)/E4BP4 and analyzed the functional impairment of NFIL3/E4BP4-deficient basophils in vitro and in vivo using an oxazolone-induced murine model of allergic dermatitis. RESULTS: We report a new mitotic transitional basophil precursor population (referred to as transitional basophils) that expresses the FcεRIα chain at higher levels than mature basophils. Transitional basophils are less responsive to IgE-linked degranulation but produce more cytokines in response to IL-3, IL-33, or IgE cross-linking than mature basophils. In particular, we found that the expression of NFIL3/E4BP4 gradually rises as cells mature from the basophil progenitor stage. Basophil-specific deletion of NFIL3/E4BP4 reduces the expression of genes necessary for basophil function and impairs IgE receptor signaling, cytokine secretion, and degranulation in the context of murine atopic dermatitis. CONCLUSIONS: We discovered transitional basophils, a novel late-stage mitotic basophil precursor cell population that exists between basophil progenitors and postmitotic mature basophils. We demonstrated that NFIL3/E4BP4 augments the IgE-mediated functions of basophils, pointing to a potential therapeutic regulator for allergic diseases.
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Factores de Transcripción con Cremalleras de Leucina de Carácter Básico , Basófilos , Animales , Ratones , Basófilos/citología , Basófilos/metabolismo , Dermatitis Atópica/metabolismo , Hipersensibilidad/metabolismo , Inmunoglobulina E/metabolismo , Interleucina-3/metabolismo , Factores de Transcripción/metabolismo , Factores de Transcripción con Cremalleras de Leucina de Carácter Básico/metabolismoRESUMEN
IL-31 receptor blockade suppresses pruritus of atopic dermatitis. However, cell-type-specific contributions of IL-31 receptor to itch, its expression mechanism, and the downstream signaling pathway to induce itch remain unknown. Here, using conditional knockout mice, we demonstrate that IL-31-induced itch requires sensory neuronal IL-31 receptor and STAT3. We find that IL-31 receptor expression is dependent on STAT3 in sensory neurons. In addition, pharmacological experiments suggest that STAT3 activation is important for the itch-inducing signaling downstream of the IL-31 receptor. A cutaneous IL-31 injection induces the nuclear accumulation of activated STAT3 first in sensory neurons that abundantly express IL-31 receptor and then in other itch-transmitting neurons. IL-31 enhances itch induced by various pruritogens including even chloroquine. Finally, pruritus associated with dermatitis is partially dependent on sensory neuronal IL-31 receptor and strongly on sensory neuronal STAT3. Thus, sensory neuronal STAT3 is essential for IL-31-induced itch and further contributes to IL-31-independent inflammatory itch.
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Dermatitis Atópica , Prurito , Animales , Ratones , Dermatitis Atópica/metabolismo , Expresión Génica , Ratones Noqueados , Prurito/inducido químicamente , Prurito/genética , Prurito/metabolismo , Células Receptoras Sensoriales/metabolismo , Piel/metabolismoRESUMEN
Circadian clocks temporally orchestrate biological processes critical for cellular/organ function. For example, the cardiomyocyte circadian clock modulates cardiac metabolism, signaling, and electrophysiology over the course of the day, such that, disruption of the clock leads to age-onset cardiomyopathy (through unknown mechanisms). Here, we report that genetic disruption of the cardiomyocyte clock results in chronic induction of the transcriptional repressor E4BP4. Importantly, E4BP4 deletion prevents age-onset cardiomyopathy following clock disruption. These studies also indicate that E4BP4 regulates both cardiac metabolism (eg, fatty acid oxidation) and electrophysiology (eg, QT interval). Collectively, these studies reveal that E4BP4 is a novel regulator of both cardiac physiology and pathophysiology.
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Sun et al. provide comprehensive evidence that the transcription factor BCL6 functions as a gatekeeper for CD8+ progenitor cell function in tumors and prevents their excessive terminal differentiation, thereby preserving this stem-like population for long-term tumor control.
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Neoplasias , Factores de Transcripción , Humanos , Proteínas Proto-Oncogénicas c-bcl-6/genética , Proteínas Proto-Oncogénicas c-bcl-6/metabolismo , Factores de Transcripción/genética , Regulación de la Expresión GénicaRESUMEN
Raptor, a key component of mTORC1, is required for recruiting substrates to mTORC1 and contributing to its subcellular localization. Raptor has a highly conserved N-terminus domain and seven WD40 repeats, which interact with mTOR and other mTORC1-related proteins. mTORC1 participates in various cellular events and mediates differentiation and metabolism. Directly or indirectly, many factors mediate the differentiation and function of lymphocytes that is essential for immunity. In this review, we summarize the role of Raptor in lymphocytes differentiation and function, whereby Raptor mediates the secretion of cytokines to induce early lymphocyte metabolism, development, proliferation and migration. Additionally, Raptor regulates the function of lymphocytes by regulating their steady-state maintenance and activation.
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Citocinas , Transducción de Señal , Proteína Reguladora Asociada a mTOR/genética , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Citocinas/metabolismoRESUMEN
Immunoglobulin A (IgA) is the most abundant isotype of antibodies and provides a first line of defense at the mucosa against pathogens invading the host. It has been widely accepted that the mucosal IgA response provided by vaccination requires mucosal inoculation, and intranasal inoculation has been proposed for vaccines against influenza virus. Considering the difficulty of intranasal vaccination in infants or elderly people, however, parenteral vaccination that provides the mucosal IgA response is desirable. Here, we demonstrate that subcutaneous immunisation with zymosan, a yeast cell wall constituent known to be recognised by Dectin-1 and TLR2, potentiates the production of antigen-specific IgA antibodies in the sera and airway mucosa upon intranasal antigen challenge. We confirmed that the antigen-specific IgA-secreting cells accumulated in the lung and nasal-associated lymphoid tissues after the antigen challenge. Such an adjuvant effect of zymosan in the primary immunisation for the IgA response depended on Dectin-1 signalling, but not on TLR2. The IgA response to the antigen challenge required both antigen-specific memory B and T cells, and the generation of memory T cells, but not memory B cells, depended on zymosan as an adjuvant. Finally, we demonstrated that subcutaneous inoculation of inactivated influenza virus with zymosan, but not with alum, mostly protected the mice from infection with a lethal dose of a heterologous virus strain. These data suggest that zymosan is a possible adjuvant for parenteral immunisation that generates memory IgA responses to respiratory viruses such as influenza virus.
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Enfermedades Transmisibles , Vacunas contra la Influenza , Gripe Humana , Infecciones por Orthomyxoviridae , Orthomyxoviridae , Ratones , Animales , Humanos , Inmunoglobulina A , Zimosan/farmacología , Receptor Toll-Like 2 , Anticuerpos Antivirales , Inmunización , Vacunación , Administración Intranasal , Adyuvantes Inmunológicos/farmacología , Membrana Mucosa , Antígenos , Inmunidad MucosaRESUMEN
Group 2 innate lymphoid cells (ILC2s) expressing IL-5 and IL-13 are localized at various mucosal tissues and play critical roles in the induction of type 2 inflammation, response to helminth infection, and tissue repair. Here, we reveal a unique ILC2 subset in the mouse intestine that constitutively expresses IL-4 together with GATA3, ST2, KLRG1, IL-17RB, and IL-5. In this subset, IL-4 expression is regulated by mechanisms similar to but distinct from those observed in T cells and is partly affected by IL-25 signaling. Although the absence of the microbiota had marginal effects, feeding mice with a vitamin B1-deficient diet compromised the number of intestinal IL-4+ ILC2s. The decrease in the number of IL-4+ ILC2s caused by the vitamin B1 deficiency was accompanied by a reduction in IL-25-producing tuft cells. Our findings reveal that dietary vitamin B1 plays a critical role in maintaining interaction between tuft cells and IL-4+ ILC2s, a previously uncharacterized immune cell population that may contribute to maintaining intestinal homeostasis.
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Dieta , Mucosa Intestinal , Tiamina , Animales , Ratones , Mucosa Intestinal/citología , Mucosa Intestinal/inmunología , Tiamina/metabolismo , Organismos Libres de Patógenos Específicos , Ratones Endogámicos C57BL , Interleucina-4/metabolismo , Microbioma Gastrointestinal , Organoides/citología , Organoides/inmunología , Ácido TrinitrobencenosulfónicoRESUMEN
Posttranslational modification, such as phosphorylation, is an important biological event that modulates and diversifies protein function. Bcl11b protein is a zinc-finger transcription factor that plays a crucial role in early T cell development and the segregation of T cell subsets. Bcl11b possesses at least 25 serine/threonine (S/T) residues that can be phosphorylated upon TCR stimulation. To understand the physiological relevance of the phosphorylation on Bcl11b protein, we replaced S/T residues with alanine (A) by targeting murine Bcl11b gene in embryonic stem cells. By combinational targeting of exons 2 and 4 in the Bcl11b gene, we generated a mouse strain, Bcl11b-phosphorylation site mutation mice, in which 23 S/T residues were replaced with A residues. Such extensive manipulation left only five putative phosphorylated residues, two of which were specific for mutant protein, and resulted in reduced amounts of Bcl11b protein. However, primary T cell development in the thymus, as well as the maintenance of peripheral T cells, remained intact even after loss of major physiological phosphorylation. In addition, in vitro differentiation of CD4+ naive T cells into effector Th cell subsets-Th1, Th2, Th17, and regulatory T-was comparable between wild-type and Bcl11b-phosphorylation site mutation mice. These findings indicate that the physiological phosphorylation on major 23 S/T residues in Bcl11b is dispensable for Bcl11b functions in early T cell development and effector Th cell differentiation.
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Proteínas Represoras , Proteínas Supresoras de Tumor , Animales , Ratones , Fosforilación , Proteínas Represoras/genética , Proteínas Supresoras de Tumor/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Diferenciación Celular , Procesamiento Proteico-Postraduccional , Serina/genética , Serina/metabolismo , Treonina/genética , Treonina/metabolismoRESUMEN
Asthma is airway inflammatory diseases caused by the activation of group 2 innate lymphoid cells (ILC2s) and type 2 helper T (TH2) cells. Cysteine proteases allergen cause tissue damage to airway epithelial cells and activate ILC2-mediated type 2 airway inflammation. FK506 is an immunosuppressive agent against calcium-dependent NFAT activation that is also effective against asthmatic inflammation. However, the effects of FK506 on cysteine protease allergen-mediated airway inflammation remain unclear. In this study, we investigated the suppressive effects of FK506 on airway inflammation. FK506 had a partial inhibitory effect on ILC2-dependent eosinophil inflammation and a robust inhibitory effect on T cell-dependent eosinophil inflammation in a cysteine protease-induced mouse asthma model. The infiltration of T1/ST2+ CD4 T cells in the lungs contributed to the persistence of eosinophil infiltration in the airway; FK506 completely inhibited the infiltration of T1/ST2+ CD4 T cells. In the initial phase, FK506 treatment targeted lung ILC2 activation induced by leukotriene B4 (LTB4)-mediated calcium signaling, but not IL-33 signaling. FK506 also inhibited the IL-13-dependent accumulation of T1/ST2+ CD4 T cells in the lungs of the later responses. These results indicated that FK506 potently suppressed airway inflammation by targeting ILC2 activation and T1/ST2+ CD4 T cell accumulation.
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Asma , Proteasas de Cisteína , Eosinofilia , Neumonía , Ratones , Animales , Inmunidad Innata , Tacrolimus/farmacología , Tacrolimus/uso terapéutico , Proteína 1 Similar al Receptor de Interleucina-1 , Linfocitos , Asma/tratamiento farmacológico , Neumonía/tratamiento farmacológico , Alérgenos , Inflamación/tratamiento farmacológicoRESUMEN
Decreased pancreatic volume, increased pancreatic fat mass, and serrated pancreatic margins are characteristic morphological changes of the pancreas in subjects with type 2 diabetes mellitus. This retrospective study aimed to clarify the clinical significance of pancreatic morphological changes in subjects with type 2 diabetes mellitus who underwent abdominal magnetic resonance imaging. The mean age and HbA1c value were 59.1 ± 16.3 years old and 8.9 ± 2.3%, respectively. Pancreatic body mass corrected for body surface area (BSA) in subjects with diabetes mellitus was lower compared to those in normal glucose tolerance (49.4 ± 15.3 cm3 vs. 60.9 ± 7.8 cm3), although it did not reach a statistic significance. There was a negative correlation between BSA-corrected pancreatic volume and age, duration of diabetes, glycoalbumin, mean and max IMT, and there was a positive correlation between BSA-corrected pancreatic volume and HOMA2-ß. Serration of the pancreatic limbus was more often observed in subjects with diabetes mellitus compared to those in normal glucose tolerance (74.1% vs. 14.3%). Subjects with serrated changes were older and had higher HbA1c, and visceral fat area was significantly larger in subjects with serrated changes. BSA-corrected pancreatic volume in subjects with serrated changes was significantly smaller, and mean IMT was significantly thicker in subjects with serrulation. Furthermore, advanced diabetic retinopathy and diabetic nephropathy were more often observed in subjects with serrated changes. Taken together, decreased BSA-corrected pancreatic volume and serrated changes were associated with the progression of vascular complications in subjects with type 2 diabetes mellitus.
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Enfermedades Cardiovasculares , Diabetes Mellitus Tipo 2 , Adulto , Anciano , Enfermedades Cardiovasculares/patología , Diabetes Mellitus Tipo 2/complicaciones , Diabetes Mellitus Tipo 2/patología , Glucosa , Hemoglobina Glucada , Humanos , Persona de Mediana Edad , Páncreas/diagnóstico por imagen , Páncreas/patología , Estudios RetrospectivosRESUMEN
Invariant natural killer T (iNKT) cells are a group of innate-like T lymphocytes that recognize lipid antigens. They are supposed to be tissue resident and important for systemic and local immune regulation. To investigate the heterogeneity of iNKT cells, we recharacterized iNKT cells in the thymus and peripheral tissues. iNKT cells in the thymus were divided into three subpopulations by the expression of the natural killer cell receptor CD244 and the chemokine receptor CXCR6 and designated as C0 (CD244-CXCR6-), C1 (CD244-CXCR6+), or C2 (CD244+CXCR6+) iNKT cells. The development and maturation of C2 iNKT cells from C0 iNKT cells strictly depended on IL-15 produced by thymic epithelial cells. C2 iNKT cells expressed high levels of IFN-γ and granzymes and exhibited more NK cell-like features, whereas C1 iNKT cells showed more T cell-like characteristics. C2 iNKT cells were influenced by the microbiome and aging and suppressed the expression of the autoimmune regulator AIRE in the thymus. In peripheral tissues, C2 iNKT cells were circulating that were distinct from conventional tissue-resident C1 iNKT cells. Functionally, C2 iNKT cells protected mice from the tumor metastasis of melanoma cells by enhancing antitumor immunity and promoted antiviral immune responses against influenza virus infection. Furthermore, we identified human CD244+CXCR6+ iNKT cells with high cytotoxic properties as a counterpart of mouse C2 iNKT cells. Thus, this study reveals a circulating subset of iNKT cells with NK cell-like properties distinct from conventional tissue-resident iNKT cells.
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Células T Asesinas Naturales , Ratones , Humanos , Animales , Células T Asesinas Naturales/metabolismo , Células T Asesinas Naturales/patología , Interleucina-15 , Antivirales , Granzimas , Receptores de Células Asesinas Naturales , Receptores de Quimiocina/metabolismo , LípidosRESUMEN
B cells secrete antibodies and mediate the humoral immune response, making them extremely important in protective immunity against SARS-CoV-2, which caused the coronavirus disease 2019 (COVID-19) pandemic. In this review, we summarize the positive function and pathological response of B cells in SARS-CoV-2 infection and re-infection. Then, we structure the immunity responses that B cells mediated in peripheral tissues. Furthermore, we discuss the role of B cells during vaccination including the effectiveness of antibodies and memory B cells, viral evolution mechanisms, and future vaccine development. This review might help medical workers and researchers to have a better understanding of the interaction between B cells and SARS-CoV-2 and broaden their vision for future investigations.