Project description:Natural Killer (NK) cells are innate cytotoxic lymphocytes with adaptive immune features, including antigen-specificity, clonal expansion, and memory. As such, NK cells share many transcriptional and epigenetic programs with their adaptive CD8+ T cell siblings. Various signals ranging from antigen, co-stimulation, and proinflammatory cytokines are required for optimal NK cell responses in mice and humans during virus infection; however, the integration of these signals remains unclear. In this study, we identified the transcription factor IRF4 as a signal integrator to coordinate the NK cell response during viral infection. Loss of IRF4 was detrimental to the expansion and differentiation of virus-specific NK cells. This defect was partially attributed to the inability of IRF4-deficient NK cells to uptake nutrients required for survival and memory generation. Altogether, these data suggest IRF4 is a signal integrator that acts as a secondary metabolic checkpoint to orchestrate the adaptive response of NK cells during viral infection.
Project description:Natural Killer (NK) cells are innate cytotoxic lymphocytes with adaptive immune features, including antigen-specificity, clonal expansion, and memory. As such, NK cells share many transcriptional and epigenetic programs with their adaptive CD8+ T cell siblings. Various signals ranging from antigen, co-stimulation, and proinflammatory cytokines are required for optimal NK cell responses in mice and humans during virus infection; however, the integration of these signals remains unclear. In this study, we identified the transcription factor IRF4 as a signal integrator to coordinate the NK cell response during viral infection. Loss of IRF4 was detrimental to the expansion and differentiation of virus-specific NK cells. This defect was partially attributed to the inability of IRF4-deficient NK cells to uptake nutrients required for survival and memory generation. Altogether, these data suggest IRF4 is a signal integrator that acts as a secondary metabolic checkpoint to orchestrate the adaptive response of NK cells during viral infection.
Project description:Chromatin protein positive coactivator 4 (PC4) has multiple functions, including chromatin compaction. However, its role in immune cells is largely unknown. We show that PC4 orchestrates chromatin structure and gene expression in mature B cells. B-cell specific PC4-deficient mice showed impaired production of antibody upon antigen stimulation. The PC4 complex purified from B cells contained transcription factors IKAROS and IRF4. IKAROS protein was reduced in PC4-deficient mature B cells, resulting in de-repression of their target genes in part by diminished interactions with gene silencing components. Upon activation, IRF4 protein amount was not increased in PC4-deficient B cells, resulting in reduction of plasma cells. Importantly, IRF4 reciprocally induced PC4 expression via a super-enhancer. PC4 knockdown in human B-cell lymphoma cells reduced IKAROS protein as an anticancer drug lenalidomide. Our findings establish PC4 as a chromatin regulator of B cells and a possible therapeutic target adjoining IKAROS in B-cell malignancies.
Project description:To evaluate the transcriptome response of roots towards Hoagland solution of two-year-old healthy (C) and HLB-affected (T) sweet orange (Citrus sinensis L.) cultivar Midsweet grafted on Kuharskei Carrizo rootstock at three different time points; D1 (at the start of the experiment), D2 (After 3 days of Hoagland solution), D3 (After nine days of Hoagland solution), were performed using RNA sequencing analysis. A total of 9, 19, and 2324 DEGs were expressed in HLB-affected and healthy trees feeder roots on D1, D2, and D3, respectively. Due to a small number of DEGs in HLB-affected and healthy trees roots on D1 and D2, enrichment analysis could not be performed. At D3, Gene Ontology (GO) enrichment analysis was performed using upregulated and downregulated DEGs in HLB-affected roots compared to healthy roots. For the upregulated DEGs in HLB-affected roots, the most enriched biological GO categories were related to transport, cellular amino acid metabolic process, oxoacid metabolic process, organic acid metabolic processes, phenylpropanoid biosynthesis process, response to carbohydrate stimulus, ethylene and the jasmonic acid-mediated signaling pathway, and regulation of plant hormone. The biological GO categories based on the number of DEGs associated with downregulated DEGs were the developmental process, phosphate metabolic process, protein modification process, defense response, growth, cell cycle, cell death, and ABA-mediated signaling pathway. The results of this study strongly suggest; although, the reduced biomass limits the nutrient uptake capacity in the plants as a whole, so in order to compensate for reduced root to shoot ratio the existing root undergo anatomical and transcriptomic changes to improve nutrient uptake efficiency to meet the nutrient demand of shoot systems. It is likely that higher inputs of energy in nutrient uptake possibly results in reducing the root longevity of HLB-affected trees. Good nutrition management practices are critical for the survival of HLB-affected trees as the availability and uptake of nutrients allow HLB-affected trees in response to abiotic and biotic stress.