RESUMO
While some infections elicit germinal centers, others produce only extrafollicular responses. The mechanisms controlling these dichotomous fates are poorly understood. We identify IL-12 as a cytokine switch, acting directly on B cells to promote extrafollicular and suppress germinal center responses. IL-12 initiates a B cell-intrinsic feed-forward loop between IL-12 and IFNγ, amplifying IFNγ production, which promotes proliferation and plasmablast differentiation from mouse and human B cells, in synergy with IL-12. IL-12 sustains the expression of a portion of IFNγ-inducible genes. Together, they also induce unique gene changes, reflecting both IFNγ amplification and cooperative effects between both cytokines. In vivo, cells lacking both IL-12 and IFNγ receptors are more impaired in plasmablast production than those lacking either receptor alone. Further, B cell-derived IL-12 enhances both plasmablast responses and T helper 1 cell commitment. Thus, B cell-derived IL-12, acting on T and B cells, determines the immune response mode, with implications for vaccines, pathogen protection and autoimmunity.
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Linfócitos B , Diferenciação Celular , Centro Germinativo , Interferon gama , Interleucina-12 , Animais , Interleucina-12/imunologia , Interleucina-12/metabolismo , Camundongos , Interferon gama/metabolismo , Interferon gama/imunologia , Centro Germinativo/imunologia , Humanos , Linfócitos B/imunologia , Linfócitos B/metabolismo , Diferenciação Celular/imunologia , Camundongos Knockout , Camundongos Endogâmicos C57BL , Plasmócitos/imunologia , Plasmócitos/metabolismo , Ativação Linfocitária/imunologia , Receptores de Interferon/metabolismo , Receptores de Interferon/genética , Células Cultivadas , Proliferação de CélulasRESUMO
Memory B cells (MBCs) are phenotypically and functionally diverse, but their developmental origins remain undefined. Murine MBCs can be divided into subsets by expression of CD80 and PD-L2. Upon re-immunization, CD80/PD-L2 double-negative (DN) MBCs spawn germinal center B cells (GCBCs), whereas CD80/PD-L2 double-positive (DP) MBCs generate plasmablasts but not GCBCs. Using multiple approaches, including generation of an inducible GCBC-lineage reporter mouse, we demonstrate in a T cell-dependent response that DN cells formed independently of the germinal center (GC), whereas DP cells exhibited either extrafollicular (DPEX) or GCBC (DPGC) origins. Chromatin and transcriptional profiling revealed similarity of DN cells with an early memory precursor. Reciprocally, GCBC-derived DP cells shared distinct genomic features with GCBCs, while DPEX cells had hybrid features. Upon restimulation, DPEX cells were more prone to divide, while DPGC cells differentiated toward IgG1+ plasmablasts. Thus, MBC functional diversity is generated through distinct developmental histories, which imprint characteristic epigenetic patterns onto their progeny, thereby programming them for divergent functional responses.
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Subpopulações de Linfócitos B , Animais , Camundongos , Células B de Memória , Epigenômica , Linfócitos B , Epigênese GenéticaRESUMO
INTRODUCTION: In a randomized clinical study, we investigated the effectiveness of nasal lignocaine spray and swabs in treating postdural puncture headache (PDPH) after spinal anesthesia. MATERIAL AND METHODS: Group S patients received two puffs of lignocaine 10% spray in both nostrils followed by cotton soaked in normal saline, and group B patients received two puffs of saline spray in both nostrils followed by a cotton swab soaked in lignocaine 2%. Patients were assessed before the procedure and 30 minutes, 60 minutes, 2 h, 24 h, 48 h, and 72 h after the procedure for pain relief with the help of a visual analogue scale (VAS). Hemodynamic parameters and adverse effects were also recorded. Normally distributed continuous variables were expressed as mean (95% confidence interval) whereas non-normally distributed variables were expressed as median (IQR). Repeated measures analysis of variance was used to compare the VAS score at different time points between test and control groups. The difference in means between the two groups was compared using the independent sample t -test. The paired t-test was used to compare the changes in clinical and laboratory variables. RESULTS: At each time point, the mean VAS score for pain was substantially different between the two groups. Moreover, until the second hour, the VAS score was significantly lower in group S than in group B. No significant intervention-related adverse effect was observed in either group. CONCLUSIONS: Without any noticeable side effects, lignocaine 10% spray is more successful in treating PDPH after spinal anesthesia, particularly in the first two hours.
Assuntos
Raquianestesia , Cefaleia Pós-Punção Dural , Bloqueio do Gânglio Esfenopalatino , Humanos , Lidocaína/uso terapêutico , Bloqueio do Gânglio Esfenopalatino/métodos , Raquianestesia/efeitos adversos , Cefaleia Pós-Punção Dural/terapia , Dor/etiologia , Punção Espinal/efeitos adversosRESUMO
Intestinal helminth infection promotes a Type 2 inflammatory response in resistant C57BL/6 mice that is essential for worm clearance. The study of inbred mouse strains has revealed factors that are critical for parasite resistance and delineated the role of Type 1 versus Type 2 immune responses in worm clearance. In C57BL/6 mice, basophils are key innate immune cells that promote Type 2 inflammation and are programmed via the Notch signalling pathway during infection with the helminth Trichuris muris. However, how the host genetic background influences basophil responses and basophil expression of Notch receptors remains unclear. Here we use genetically susceptible inbred AKR/J mice that have a Type 1-skewed immune response during T. muris infection to investigate basophil responses in a susceptible host. Basophil population expansion occurred in AKR/J mice even in the absence of fulminant Type 2 inflammation during T. muris infection. However, basophils in AKR/J mice did not robustly upregulate expression of the Notch2 receptor in response to infection as occurred in C57BL/6 mice. Blockade of the Type 1 cytokine interferon-γ in infected AKR/J mice was not sufficient to elicit infection-induced basophil expression of the Notch2 receptor. These data suggest that the host genetic background, outside of the Type 1 skew, is important in regulating basophil responses during T. muris infection in susceptible AKR/J mice.
Assuntos
Parasitos , Tricuríase , Animais , Camundongos , Camundongos Endogâmicos AKR , Trichuris , Basófilos , Receptor Notch2 , Camundongos Endogâmicos C57BL , Suscetibilidade a Doenças , InflamaçãoRESUMO
Age-associated B cells (ABCs) are formed under inflammatory conditions and are considered a type of memory B cell (MBC) expressing the transcription factor T-bet. In SLE, ABC frequency is correlated with disease, and they are thought to be the source of autoantibody-secreting cells. However, in inflammatory conditions, whether autoreactive B cells can become resting MBCs is uncertain. Further, the phenotypic identity of ABCs and their relationship to other B cell subsets, such as plasmablasts, is unclear. Whether ABCs directly promote disease is untested. Here we report, in the MRL/lpr SLE model, unexpected heterogeneity among ABC-like cells for expression of the integrins CD11b and CD11c, T-bet, and memory or plasmablast markers. Transfer and labeling studies demonstrated that ABCs are dynamic, rapidly turning over. scRNA-seq identified B cell clones present in multiple subsets, revealing that ABCs can be plasmablast precursors or undergo cycles of reactivation. Deletion of CD11c-expressing B cells revealed a direct role for ABC-like B cells in lupus pathogenesis.
Assuntos
Subpopulações de Linfócitos B , Lúpus Eritematoso Sistêmico , Camundongos , Animais , Autoimunidade , Linfócitos B , Camundongos Endogâmicos MRL lpr , Lúpus Eritematoso Sistêmico/metabolismoRESUMO
Both B cell receptor (BCR) and CD40 signaling are rewired in germinal center (GC) B cells (GCBCs) to synergistically induce c-MYC and phosphorylated S6 ribosomal protein (p-S6), markers of positive selection. How interleukin-21 (IL-21), a key T follicular helper (TFH)-derived cytokine, affects GCBCs is unclear. Like BCR and CD40 signals, IL-21 receptor (IL-21R) plus CD40 signals also synergize to induce c-MYC and p-S6 in GCBCs. However, IL-21R plus CD40 stimulation differentially affects GCBC fate compared with BCR plus CD40 ligation-engaging unique molecular mechanisms-as revealed by bulk RNA sequencing (RNA-seq), single-cell RNA-seq, and flow cytometry of GCBCs in vitro and in vivo. Whereas both signal pairs induced BLIMP1 in some GCBCs, only the IL-21R/CD40 combination induced IRF4hi/CD138+ cells, indicative of plasma cell differentiation, along with CCR6+/CD38+ memory B cell precursors. These findings reveal a second positive selection pathway in GCBCs, document rewired IL-21R signaling in GCBCs, and link specific TFH- and Ag-derived signals to GCBC differentiation.
Assuntos
Linfócitos B , Centro Germinativo , Receptores de Interleucina-21 , Linfócitos B/metabolismo , Antígenos CD40 , Centro Germinativo/metabolismo , Receptores de Antígenos de Linfócitos B/metabolismo , Transdução de Sinais , Receptores de Interleucina-21/metabolismoRESUMO
Dendritic cell (DC) fine-tunes inflammatory versus tolerogenic responses to protect from immune-pathology. However, the role of co-regulators in maintaining this balance is unexplored. NCoR1-mediated repression of DC immune-tolerance has been recently reported. Here we found that depletion of NCoR1 paralog SMRT (NCoR2) enhanced cDC1 activation and expression of IL-6, IL-12 and IL-23 while concomitantly decreasing IL-10 expression/secretion. Consequently, co-cultured CD4+ and CD8+ T-cells depicted enhanced Th1/Th17 frequency and cytotoxicity, respectively. Comparative genomic and transcriptomic analysis demonstrated differential regulation of IL-10 by SMRT and NCoR1. SMRT depletion represses mTOR-STAT3-IL10 signaling in cDC1 by down-regulating NR4A1. Besides, Nfkbia and Socs3 were down-regulated in Ncor2 (Smrt) depleted cDC1, supporting increased production of inflammatory cytokines. Moreover, studies in mice showed, adoptive transfer of SMRT depleted cDC1 in OVA-DTH induced footpad inflammation led to increased Th1/Th17 and reduced tumor burden after B16 melanoma injection by enhancing oncolytic CD8+ T-cell frequency, respectively. We also depicted decreased Ncor2 expression in Rheumatoid Arthritis, a Th1/Th17 disease.
Assuntos
Interleucina-10 , Interleucina-6 , Animais , Linfócitos T CD8-Positivos/metabolismo , Citocinas/metabolismo , Células Dendríticas/metabolismo , Interleucina-10/metabolismo , Interleucina-12/metabolismo , Interleucina-23/metabolismo , Interleucina-6/metabolismo , Camundongos , Correpressor 1 de Receptor Nuclear/genética , Correpressor 1 de Receptor Nuclear/metabolismo , Correpressor 2 de Receptor Nuclear , Fator de Transcrição STAT3 , Serina-Treonina Quinases TOR/metabolismoRESUMO
In lupus, Toll-like receptor 7 (TLR7) and TLR9 mediate loss of tolerance to RNA and DNA, respectively. Yet, TLR7 promotes disease, while TLR9 protects from disease, implying differences in signaling. To dissect this 'TLR paradox', we generated two TLR9 point mutants (lacking either ligand (TLR9K51E) or MyD88 (TLR9P915H) binding) in lupus-prone MRL/lpr mice. Ameliorated disease of Tlr9K51E mice compared to Tlr9-/- controls revealed a TLR9 'scaffold' protective function that is ligand and MyD88 independent. Unexpectedly, Tlr9P915H mice were more protected than both Tlr9K51E and Tlr9WT mice, suggesting that TLR9 also possesses ligand-dependent, but MyD88-independent, regulatory signaling and MyD88-mediated proinflammatory signaling. Triple-mixed bone marrow chimeras showed that TLR9-MyD88-independent regulatory roles were B cell intrinsic and restrained differentiation into pathogenic age-associated B cells and plasmablasts. These studies reveal MyD88-independent regulatory roles of TLR9, shedding light on the biology of endosomal TLRs.
Assuntos
Receptor 7 Toll-Like , Receptor Toll-Like 9 , Animais , DNA , Ligantes , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos MRL lpr , Camundongos Knockout , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , RNA , Receptor 7 Toll-Like/genética , Receptor 7 Toll-Like/metabolismo , Receptor Toll-Like 9/genética , Receptor Toll-Like 9/metabolismoRESUMO
We previously found that kidney-infiltrating T cells (KITs) in murine lupus nephritis (LN) resembled dysfunctional T cells that infiltrate tumors. This unexpected finding raised the question of how to reconcile the "exhausted" phenotype of KITs with ongoing tissue destruction in LN. To address this, we performed single-cell RNA-Seq and TCR-Seq of KITs in murine lupus models. We found that CD8+ KITs existed first in a transitional state, before clonally expanding and evolving toward exhaustion. On the other hand, CD4+ KITs did not fit into current differentiation paradigms but included both hypoxic and cytotoxic subsets with a pervasive exhaustion signature. Thus, autoimmune nephritis is unlike acute pathogen immunity; rather, the kidney microenvironment suppresses T cells by progressively inducing exhausted states. Our findings suggest that LN, a chronic condition, results from slow evolution of damage caused by dysfunctional T cells and their precursors on the way to exhaustion. These findings have implications for both autoimmunity and tumor immunology.
Assuntos
Nefrite Lúpica , Animais , Autoimunidade , Linfócitos T CD8-Positivos , Feminino , Humanos , Rim/patologia , Contagem de Linfócitos , Masculino , CamundongosRESUMO
Memory B cells (MBCs) protect the body from recurring infections. MBCs differ from their naive counterparts (NBCs) in many ways, but functional and surface marker differences are poorly characterized. In addition, although mice are the prevalent model for human immunology, information is limited concerning the nature of homology in B cell compartments. To address this, we undertook an unbiased, large-scale screening of both human and mouse MBCs for their differential expression of surface markers. By correlating the expression of such markers with extensive panels of known markers in high-dimensional flow cytometry, we comprehensively identified numerous surface proteins that are differentially expressed between MBCs and NBCs. The combination of these markers allows for the identification of MBCs in humans and mice and provides insight into their functional differences. These results will greatly enhance understanding of humoral immunity and can be used to improve immune monitoring.
Assuntos
Linfócitos B/imunologia , Memória Imunológica/imunologia , Células B de Memória/imunologia , Animais , Linfócitos B/metabolismo , Biomarcadores/metabolismo , Feminino , Citometria de Fluxo/métodos , Humanos , Imunidade Humoral/imunologia , Masculino , Células B de Memória/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , FenótipoRESUMO
Type 2 inflammation is associated with epithelial cell responses, including goblet cell hyperplasia, that promote worm expulsion during intestinal helminth infection. How these epithelial responses are regulated remains incompletely understood. Here, we show that mice deficient in the prostaglandin D2 (PGD2) receptor CRTH2 and mice with CRTH2 deficiency only in nonhematopoietic cells exhibited enhanced worm clearance and intestinal goblet cell hyperplasia following infection with the helminth Nippostrongylus brasiliensis. Small intestinal stem, goblet, and tuft cells expressed CRTH2. CRTH2-deficient small intestinal organoids showed enhanced budding and terminal differentiation to the goblet cell lineage. During helminth infection or in organoids, PGD2 and CRTH2 down-regulated intestinal epithelial Il13ra1 expression and reversed Type 2 cytokine-mediated suppression of epithelial cell proliferation and promotion of goblet cell accumulation. These data show that the PGD2-CRTH2 pathway negatively regulates the Type 2 cytokine-driven epithelial program, revealing a mechanism that can temper the highly inflammatory effects of the anti-helminth response.
Assuntos
Citocinas/metabolismo , Mucosa Intestinal/parasitologia , Prostaglandina D2/metabolismo , Receptores Imunológicos/metabolismo , Receptores de Prostaglandina/metabolismo , Infecções por Strongylida/parasitologia , Animais , Feminino , Gastroenterite/parasitologia , Gastroenterite/patologia , Células Caliciformes/patologia , Interações Hospedeiro-Parasita/fisiologia , Mucosa Intestinal/patologia , Masculino , Camundongos Endogâmicos C57BL , Nippostrongylus/patogenicidade , Organoides , Receptores Imunológicos/genética , Receptores de Prostaglandina/genética , Infecções por Strongylida/patologiaRESUMO
Transition of grapevine buds from paradormancy to endodormancy is coordinated by changes in gene expression, phytohormones, transcription factors, and other molecular regulators, but the mechanisms involved in transcriptional and post-transcriptional regulation of dormancy stages are not well delineated. To identify potential regulatory targets, an integrative analysis of differential gene expression profiles and their inverse relationships with miRNA abundance was performed in paradormant (long day (LD) 15 h) or endodormant (short day (SD), 13 h) Vitis riparia buds. There were 400 up- and 936 downregulated differentially expressed genes in SD relative to LD budsGene set and gene ontology enrichment analysis indicated that hormone signaling and cell cycling genes were downregulated in SD relative to LD buds. miRNA abundance and inverse expression analyses of miRNA target genes indicated increased abundance of miRNAs that negatively regulate genes involved with cell cycle and meristem development in endodormant buds and miRNAs targeting starch metabolism related genes in paradormant buds. Analysis of interactions between abundant miRNAs and transcription factors identified a network with coinciding regulation of cell cycle and epigenetic regulation related genes in SD buds. This network provides evidence for cross regulation occurring between miRNA and transcription factors both upstream and downstream of MYB3R1.
RESUMO
Dendritic cell (DC) activation and cytokine production is tightly regulated. In this study, we found that Zbtb10 expression is activation dependent and it is essential for the immunogenic function of cDC1. Zbtb10 knockdown (KD) significantly reduced the expression of co-stimulatory genes CD80 and CD86 along with cytokines including IL-12, IL-6, and IL-10, in activated cDC1 Mutu-DC line. Consequently, the clonal expansion of CD44+ effector T cells in co-cultured CD4+ T cells was drastically reduced owing to significantly reduced IL-2. At the same time, these CD44+ effector T cells were unable to differentiate toward Tbet+ IFNγ+ Th1 subtype. Instead, an increased frequency of Th2 cells expressing GATA3+ and IL-13+ was observed. Interestingly, in Zbtb10 KD condition the co-cultured T cells depicted increased expression of PD1 and LAG3, the T-cell anergic markers. Moreover, the global transcriptome analysis identified that Zbtb10 is pertinent for DC activation and its depletion in cDC1 completely shuts down their immune responses. Mechanistic analysis revealed that Zbtb10 KD enhanced the expression of NKRF (NF-κB repressing factor) leading to drastic suppression of NF-κB related genes. Zbtb10 KD abrogated p65 and RelB nuclear translocation, thereby controlling the activation and maturation of cDC1 and the ensuing adaptive T cell responses.
Assuntos
Citocinas/biossíntese , Células Dendríticas/imunologia , Células Dendríticas/metabolismo , Fatores de Transcrição/metabolismo , Animais , Biomarcadores , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Linhagem Celular , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Ativação Linfocitária/imunologia , Camundongos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismoRESUMO
Rewiring tumor cells to undergo drug-induced apoptosis is a promising way to overcome chemoresistance. Therefore, identifying causative factors for chemoresistance is of high importance. Unbiased global proteome profiling of sensitive, early, and late cisplatin-resistant oral squamous cell carcinoma (OSCC) lines identified CMTM6 as a top-ranked upregulated protein. Analyses of OSCC patient tumor samples demonstrated significantly higher CMTM6 expression in chemotherapy (CT) nonresponders as compared with CT responders. In addition, a significant association between higher CMTM6 expression and poorer relapse-free survival in esophageal squamous cell carcinoma, head and neck squamous cell carcinoma, and lung squamous cell carcinoma was observed from Kaplan-Meier plot analysis. Stable knockdown (KD) of CMTM6 restored cisplatin-mediated cell death in chemoresistant OSCC lines. Upon CMTM6 overexpression in CMTM6-KD lines, the cisplatin-resistant phenotype was rescued. The patient-derived cell xenograft model of chemoresistant OSCC displaying CMTM6 depletion restored the cisplatin-induced cell death and tumor burden substantially. The transcriptome analysis of CMTM6-KD and control chemoresistant cells depicted enrichment of the Wnt signaling pathway. We demonstrated that CMTM6 interaction with membrane-bound Enolase-1 stabilized its expression, leading to activation of Wnt signaling mediated by AKT-glycogen synthase kinase-3ß. CMTM6 has been identified as a stabilizer of programmed cell death ligand 1. Therefore, as CMTM6 facilitates tumor cells for immune evasion and mediates cisplatin resistance, it could be a promising therapeutic target for treating therapy-resistant OSCC.
Assuntos
Cisplatino/farmacologia , Proteínas de Ligação a DNA/metabolismo , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta/metabolismo , Proteínas da Mielina/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Via de Sinalização Wnt/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Biomarcadores Tumorais/metabolismo , Carcinoma de Células Escamosas/patologia , Morte Celular , Linhagem Celular Tumoral , Neoplasias Esofágicas/genética , Carcinoma de Células Escamosas do Esôfago/tratamento farmacológico , Carcinoma de Células Escamosas do Esôfago/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glicogênio Sintase Quinase 3 beta/genética , Neoplasias de Cabeça e Pescoço/tratamento farmacológico , Neoplasias de Cabeça e Pescoço/genética , Humanos , Proteínas com Domínio MARVEL , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Neoplasias Bucais/tratamento farmacológico , Neoplasias Bucais/patologia , Proteínas da Mielina/genética , Fosfopiruvato Hidratase/metabolismo , Carcinoma de Células Escamosas de Cabeça e Pescoço/tratamento farmacológico , Carcinoma de Células Escamosas de Cabeça e Pescoço/genética , Proteínas Supressoras de Tumor/metabolismo , Regulação para Cima/efeitos dos fármacosRESUMO
Coronavirus disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus, has emerged as a global pandemic worldwide. In this study, we used ARTIC primers-based amplicon sequencing to profile 225 SARS-CoV-2 genomes from India. Phylogenetic analysis of 202 high-quality assemblies identified the presence of all the five reported clades 19A, 19B, 20A, 20B, and 20C in the population. The analyses revealed Europe and Southeast Asia as two major routes for introduction of the disease in India followed by local transmission. Interestingly, the19B clade was found to be more prevalent in our sequenced genomes (17%) compared to other genomes reported so far from India. Haplotype network analysis showed evolution of 19A and 19B clades in parallel from predominantly Gujarat state in India, suggesting it to be one of the major routes of disease transmission in India during the months of March and April, whereas 20B and 20C appeared to evolve from 20A. At the same time, 20A and 20B clades depicted prevalence of four common mutations 241 C > T in 5' UTR, P4715L, F942F along with D614G in the Spike protein. D614G mutation has been reported to increase virus shedding and infectivity. Our molecular modeling and docking analysis identified that D614G mutation resulted in enhanced affinity of Spike S1-S2 hinge region with TMPRSS2 protease, possibly the reason for increased shedding of S1 domain in G614 as compared to D614. Moreover, we also observed an increased concordance of G614 mutation with the viral load, as evident from decreased Ct value of Spike and the ORF1ab gene.
RESUMO
Plasmacytoid dendritic cells (DCs) are reported to induce robust type-I interferon (IFN) response, whereas cDC1 DCs develop moderate type-I IFN response upon TLR9 stimulation. It is very interesting to understand how this signaling under TLR9 is tightly regulated for the induction of type-I IFNs. Here, we report co-repressor protein NCoR1 as the major factor fine-tuning the signaling pathways regulating IFN-ß expression under TLR9 in cDC1 DCs. We found that NCoR1 knockdown induced a robust IFN-ß-mediated antiviral response upon TLR9 activation in cDC1 DCs. At the molecular level, we showed that NCoR1 directly repressed MyD88-IRF7 signaling axis in cDC1 cells. Therefore, NCoR1 depletion enhanced pIRF7 levels, IFN-ß secretion, and downstream pSTAT1-pSTAT2 signaling, leading to sustained induction of IFN stimulatory genes. Integrative genomic analysis depicted strong enrichment of an antiviral gene-module in CpG-activated NCoR1 knockdown DCs upon TLR9 activation. Moreover, we confirmed our findings in primary DCs derived from splenocytes of WT and NCoR1 DC-/- animals, which showed protection from Sendai and Vesicular Stomatitis viruses upon CpG activation. Ultimately, we identified that NCoR1-HDAC3 complex is involved in repressing the type-I IFN response in cDC1 DCs.
Assuntos
Células Dendríticas/metabolismo , Fator Regulador 7 de Interferon/metabolismo , Interferon Tipo I/metabolismo , Fator 88 de Diferenciação Mieloide/metabolismo , Correpressor 1 de Receptor Nuclear/metabolismo , Receptor Toll-Like 9/metabolismo , Animais , Células Cultivadas , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Transdução de Sinais/fisiologiaRESUMO
Germinal center B cells (GCBCs) are critical for generating long-lived humoral immunity. How GCBCs meet the energetic challenge of rapid proliferation is poorly understood. Dividing lymphocytes typically rely on aerobic glycolysis over oxidative phosphorylation for energy. Here we report that GCBCs are exceptional among proliferating B and T cells, as they actively oxidize fatty acids (FAs) and conduct minimal glycolysis. In vitro, GCBCs had a very low glycolytic extracellular acidification rate but consumed oxygen in response to FAs. [13C6]-glucose feeding revealed that GCBCs generate significantly less phosphorylated glucose and little lactate. Further, GCBCs did not metabolize glucose into tricarboxylic acid (TCA) cycle intermediates. Conversely, [13C16]-palmitic acid labeling demonstrated that GCBCs generate most of their acetyl-CoA and acetylcarnitine from FAs. FA oxidation was functionally important, as drug-mediated and genetic dampening of FA oxidation resulted in a selective reduction of GCBCs. Hence, GCBCs appear to uncouple rapid proliferation from aerobic glycolysis.
Assuntos
Linfócitos B/metabolismo , Ácidos Graxos/metabolismo , Centro Germinativo/metabolismo , Animais , Linfócitos B/imunologia , Proliferação de Células , Metabolismo Energético , Ácidos Graxos não Esterificados/metabolismo , Expressão Gênica , Centro Germinativo/citologia , Centro Germinativo/imunologia , Glucose/metabolismo , Glicólise/genética , Técnicas In Vitro , Metaboloma , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Knockout , Oxirredução , Fosforilação Oxidativa , Consumo de OxigênioRESUMO
Abiotic stress tolerance is a complex trait regulated by multiple genes and gene networks in plants. A range of abiotic stresses are known to limit rice productivity. Meta-transcriptomics has emerged as a powerful approach to decipher stress-associated molecular network in model crops. However, retaining specificity of gene expression in tolerant and susceptible genotypes during meta-transcriptome analysis is important for understanding genotype-dependent stress tolerance mechanisms. Addressing this aspect, we describe here "abiotic stress tolerant" (ASTR) genes and networks specifically and differentially expressing in tolerant rice genotypes in response to different abiotic stress conditions. We identified 6,956 ASTR genes, key hub regulatory genes, transcription factors, and functional modules having significant association with abiotic stress-related ontologies and cis-motifs. Out of the 6956 ASTR genes, 73 were co-located within the boundary of previously identified abiotic stress trait-related quantitative trait loci. Functional annotation of 14 uncharacterized ASTR genes is proposed using multiple computational methods. Around 65% of the top ASTR genes were found to be differentially expressed in at least one of the tolerant genotypes under different stress conditions (cold, salt, drought, or heat) from publicly available RNAseq data comparison. The candidate ASTR genes specifically associated with tolerance could be utilized for engineering rice and possibly other crops for broad-spectrum tolerance to abiotic stresses.
Assuntos
Perfilação da Expressão Gênica , Redes Reguladoras de Genes , Oryza/genética , Estresse Fisiológico/genética , Temperatura Baixa , Secas , Genótipo , Temperatura Alta , Locos de Características Quantitativas , RNA-Seq , SalinidadeRESUMO
The B cell response to Ehrlichia muris is dominated by plasmablasts (PBs), with few-if any-germinal centers (GCs), yet it generates protective immunoglobulin M (IgM) memory B cells (MBCs) that express the transcription factor T-bet and harbor V-region mutations. Because Ehrlichia prominently infects the liver, we investigated the nature of liver B cell response and that of the spleen. B cells within infected livers proliferated and underwent somatic hypermutation (SHM). Vh-region sequencing revealed trafficking of clones between the spleen and liver and often subsequent local clonal expansion and intraparenchymal localization of T-bet+ MBCs. T-bet+ MBCs expressed MBC subset markers CD80 and PD-L2. Many T-bet+ MBCs lacked CD11b or CD11c expression but had marginal zone (MZ) B cell phenotypes and colonized the splenic MZ, revealing T-bet+ MBC plasticity. Hence, liver and spleen are generative sites of B cell responses, and they include V-region mutation and result in liver MBC localization.