Project description:Background Dysregulation of major histocompatibility complex (MHC) class I antigen processing and presentation machinery (APM) components in the tumor as one main molecular mechanism of immune escape leading to deactivation of T cell immune surveillance could be due to post-transcriptional regulation via immune-modulatory microRNAs (miRNA). It is now well established from a variety of studies that several miRNAs could effectively modulate the expression of some MHC class I APM components in tumors. Tapasin is an important APM molecule involved in the association of MHC class I with transporter associated with antigen processing (TAP) and peptide loading. Since so far no detailed investigation of the posttranscriptional regulation of tapasin exists, the aim of this study is to identify and functionally characterize miRNAs targeting tapasin in melanoma. Methods Using miRNA trapping by RNA in vitro affinity purification (miTRAP) and in silico as well as small RNA sequencing, miRNAs will be identified, which bind to the 3'untranslated region (3' UTR) of tapasin. Dual luciferase assays will be performed to determine binding of the miRNA. In silico analysis was performed to predict the effect of miRNAs on the survival of melanoma patients in correlation to tapasin. RT-qPCR, Western blot, flow cytometry and other functional assays were performed after transfecting miRNA mimics in three melanoma cell lines. Results Using the combination strategy of miTRAP and RNA seq we identified miR-155-5p to bind to the 3’UTR of tapasin, which was further confirmed by in silico analysis and dual luciferase reporter assay. Transfection of miR-155-5p mimics demonstrated that miR-155-5p upregulate tapasin protein level, which was accompanied by an upregulation of the MHC class I (HLA-ABC) surface expression. Simultaneously, in several different types of cancer, including melanoma, the expression of miR-155-5p is significantly positively correlated with the patient's survival and HLA-A protein. Conclusion Our data revealed for the first time a positive role of miR-155-5p in the posttranscriptional regulation of tapasin in melanoma and provide further insights into the miR-155-5p-mediated induction of HLA-ABC surface expression. This might lead to a better T cell response, avoidance tumor cell escape, improvement of patients' survival and thus might be a potential therapeutic target.

Project description:In the present study we analyzed miRNA and mRNA expression profiles in human peripheral blood lymphocytes (PBLs) incubated in microgravity condition, simulated by a ground-based Rotating Wall Vessel (RWV) bioreactor. Our results show that 42 miRNAs were differentially expressed in MMG-incubated PBLs compared with 1g-incubated ones. Among these, miR-9-5p, miR-9-3p, miR-155-5p, miR-150-3p, and miR-378-3p were the most dysregulated. To improve the detection of functional miRNA-mRNA pairs we performed gene expression profiles on the same samples assayed for miRNA profiling and we integrated miRNA and mRNA expression data. The functional classification of miRNA-correlated genes evidenced significant enrichments in the biological processes of immune/inflammatory response, signal transduction, regulation of response to stress, regulation of programmed cell death and regulation of cell proliferation. We identified the correlation between miR-9-3p, miR-155-5p, miR-150-3p and miR-378-3p expression with that of genes involved in immune/inflammatory response (eg. IFNG and IL17F), apoptosis (eg. PDCD4 and PTEN) and cell proliferation (eg. NKX3-1 and GADD45A). Experimental assays of cell viability and apoptosis induction validated the results obtained by bioinformatics analyses demonstrating that in human PBLs the exposure to reduced gravitational force increases the frequency of apoptosis and decreases cell proliferation. microRNA expression profiling were carried out on total RNA extracted from PBLs of twelve healthy donors at the end of 24h-incubation time in MMG and in 1g conditions. Analyses were performed by using the M-bM-^@M-^\Human miRNA Microarray kit (V2)M-bM-^@M-^] (Agilent Technologies), that allows the detection of 723 known human (miRBase v.10.1) and 76 human viral miRNAs.By comparing the expression profile of MMG-incubated vs. 1g-incubated PBLs of the same donor, we found 42 differentially expressed miRNAs, 25 up-regulated and 17 down-regulated.

Project description:Mechanisms underlying in utero fetal lung injury remain poorly defined, and a greater understanding of pathways regulating these processes may lead to novel therapies that prevent lung injury before birth. MicroRNAs (miRNAs) are small non-coding, endogenous RNAs that regulate gene expression and have been implicated in the pathogenesis of lung disease. We sought to determine whether differentially expressed miRNAs in the fetal lung following choriodecidual infection are associated with elevation of amniotic fluid (AF) cytokine levels and acute lung injury in a nonhuman primate model. After inoculating ten chronically catheterized pregnant monkeys (Macaca nemestrina) at 118-125 days gestation (term=172 days) with either Group B Streptococcus (GBS) 1 x 106 colony forming units (n=5) or saline (n=5) in the choriodecidual space, we extracted fetal lung mRNA and miRNA and profiled changes in expression. We identified 9 differentially expressed miRNAs (p<0.05, >1.5 fold change) in the GBS-exposed fetal lungs by microarray, but of these only miR-155-5p was significantly elevated by qRT-PCR (p=0.016). The microarray log2 intensity of miR-155-5p positively correlated with fetal lung injury scores and AF IL-1? and TNF-??levels (R2=0.54, p=0.016). In situ hybridization revealed that miR-155-5p is expressed throughout the fetal lung, which led us to investigate mechanisms that regulate miR-155-5p expression. Significantly elevated miR-155-5p expression was observed when immortalized human fetal airway epithelial (FeAE) cells were exposed to IL-6 and TNF-??. Overexpression of miR-155-5p in FeAE cells increased production of IL-6, CCL5/RANTES and CXCL10/IP-10. Using a luciferase reporter assay, we validated FGF9 as an authentic target of miR-155-5p, which is essential to development of the lung mesenchyme and distal epithelial branching. Collectively, these results suggest that a choriodecidual inflammatory response leads to increased AF cytokine levels, which induce miR-155-5p expression. In turn, miR-155-5p activates and recruits leukocytes (IL-6, CCL5/RANTES) and inhibits fetal lung angiogenesis (CXCL10/IP-10), meschenchymal development and epithelial branching (targets FGF9 mRNA). A therapy to antagonize miR-155-5p may ameliorate perinatal lung injury. Ten chronically catheterized pregnant monkeys (Macaca nemestrina) at 118-125 days gestation (term=172 days) received choriodecidual inoculation of either: 1) Group B Streptococcus (n=5) or 2) saline (n=5). Cesarean section and fetal necropsy was performed in the first week after GBS or saline inoculation regardless of labor. RNA was extracted from fetal lungs and profiled by microarray. Results were analyzed using single gene, Gene Set, and Ingenuity Pathway Analysis. Validation was by RT-PCR and immunohistochemistry.

Project description:Mechanisms underlying in utero fetal lung injury remain poorly defined, and a greater understanding of pathways regulating these processes may lead to novel therapies that prevent lung injury before birth. MicroRNAs (miRNAs) are small non-coding, endogenous RNAs that regulate gene expression and have been implicated in the pathogenesis of lung disease. We sought to determine whether differentially expressed miRNAs in the fetal lung following choriodecidual infection are associated with elevation of amniotic fluid (AF) cytokine levels and acute lung injury in a nonhuman primate model. After inoculating ten chronically catheterized pregnant monkeys (Macaca nemestrina) at 118-125 days gestation (term=172 days) with either Group B Streptococcus (GBS) 1 x 106 colony forming units (n=5) or saline (n=5) in the choriodecidual space, we extracted fetal lung mRNA and miRNA and profiled changes in expression. We identified 9 differentially expressed miRNAs (p<0.05, >1.5 fold change) in the GBS-exposed fetal lungs by microarray, but of these only miR-155-5p was significantly elevated by qRT-PCR (p=0.016). The microarray log2 intensity of miR-155-5p positively correlated with fetal lung injury scores and AF IL-1? and TNF-??levels (R2=0.54, p=0.016). In situ hybridization revealed that miR-155-5p is expressed throughout the fetal lung, which led us to investigate mechanisms that regulate miR-155-5p expression. Significantly elevated miR-155-5p expression was observed when immortalized human fetal airway epithelial (FeAE) cells were exposed to IL-6 and TNF-??. Overexpression of miR-155-5p in FeAE cells increased production of IL-6, CCL5/RANTES and CXCL10/IP-10. Using a luciferase reporter assay, we validated FGF9 as an authentic target of miR-155-5p, which is essential to development of the lung mesenchyme and distal epithelial branching. Collectively, these results suggest that a choriodecidual inflammatory response leads to increased AF cytokine levels, which induce miR-155-5p expression. In turn, miR-155-5p activates and recruits leukocytes (IL-6, CCL5/RANTES) and inhibits fetal lung angiogenesis (CXCL10/IP-10), meschenchymal development and epithelial branching (targets FGF9 mRNA). A therapy to antagonize miR-155-5p may ameliorate perinatal lung injury.

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Time-resolved RNA atlas of early human T cell activation (miRNA)

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