Browsing by Author "Romero, Paula Vargas"
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- Dissecting the role of microRNAs in effector versus regulatory CD4+ T cell differentiation during (auto)immune responses in vivoPublication . Cunha, Carolina; Romero, Paula Vargas; Pelicano, Catarina; Pais, Ana Teresa; Inácio, Daniel; Papotto, Pedro; Amado, Tiago; Gomes, Anita Q.; Santos-Silva, BrunoCD4+ T cells are key players in host defense against pathogens, but an incorrect balance between CD4+ T cell subsets, namely pro-inflammatory effector cells, including T helper 1 (Th)1 and Th17 cells (IFN-γ- and IL-17-producers, respectively), and anti-inflammatory regulatory cells (Treg; Foxp3+ subset), can lead to immune-mediated diseases. MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level. While individual miRNAs were shown to regulate the differentiation of specific CD4+ T cell populations, a holistic approach based on in vivo responses is missing and is critical to understanding how miRNA networks control this balance under physiological conditions. To address this, we have established a triple reporter mouse for Ifng, Il17, and Foxp3, and subject it to experimental autoimmune encephalomyelitis (EAE). We perform miRNA-seq analysis on Th1, Th17, and Treg cells isolated from the spleen (SPL) and lymph nodes (LNs) at the peak-plateau stage and found that 110 miRNAs are differentially expressed between effector and regulatory subsets. We further selected 8 candidate miRNAs that were specifically upregulated in one population versus the others. Both overexpression and inhibition studies showed that miR-126a limits IL-17+ expression in Th17 cells in vitro. Treatment with antagomiRs in vivo showed that silencing miR-122 increased the number of IL-17+ cells in the LNs and precipitated the onset of EAE, whereas inhibition of miR-1247 decreased the severity of the disease by reducing the number of IFN-γ+ cells, also in the LNs. Additionally, we identified IL-6 and TGF-β as the key cytokines upstream of miR-126a and miR-1247 expression, respectively. While both IL-6 and TGFβ also induce miR-122 expression, we found that IL-23 and IL-1β repress its expression. Interestingly, and given that IL-23 and IL-1β are critical to inducing Th17-mediated pathogenicity, we have consistently observed a pathogenic gene signature in CNS-derived Th17 cells when compared to peripheral Th17 cells with concomitantly decreased levels of miR-126a and miR-122. Overall, our results suggest that miR-126a and miR-122 regulate IL-17 expression and the pathogenic phenotype of Th17 cells to prevent excessive inflammation in the periphery while miR-1247 maintains the inflammatory phenotype of Th1 cells in an anti-inflammatory environment.
- Dissecting the role of microRNAs in effector versus regulatory CD4+ T cell differentiation during (auto)immune responses in vivoPublication . Cunha, Carolina; Romero, Paula Vargas; Inácio, Daniel; Pais, Ana Teresa; Pelicano, Catarina; Sobral, Daniel; Costa, Marina; Mensurado, Sofia; Sousa, Natacha Gonçalves; Papotto, Pedro; Enguita, Francisco; Gomes, Anita Q.; Silva-Santos, BrunoIntroduction: MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level. They have been implicated in the regulation of the differentiation and function of CD4+ T cell subsets, key players in host defense against pathogens, but also responsible for immune-mediated diseases depending on the correct vs incorrect balance, respectively, between pro-inflammatory effector CD4+T cells, including the IFN-γ-producers T helper 1 (Th)1 and the IL-17-producers Th17 cells, and anti-inflammatory regulatory T cells (Treg). While individual miRNAs were found to regulate the differentiation of specific CD4+ T cell populations, an approach based on in vivo responses is still missing and is key to understanding how miRNA networks control this balance in pathophysiology. Methodology: We have established a triple reporter mouse for Ifng, Il17, and Foxp3, and subjected it to experimental autoimmune encephalomyelitis (EAE). We performed miRNA-seq analysis on Th1, Th17, and Treg cells isolated from the spleen and lymph nodes (LNs) at the peak plateau stage to identify miRNA candidates specifically expressed in one of the cell populations. We have in vivo modulated their expression levels using antagomiRs observed the course of EAE progression and characterised their upstream regulation in vitro in either Th1 or Th17 differentiation conditions. Results: The miRNA-seq data has allowed the identification of 110 miRNAs differentially expressed between effector (Th1 and Th17) and regulatory (Treg) subsets. From those, 9 were specifically upregulated in one population versus the others. In vivo miRNA modulation showed that silencing miR-122 precipitated the onset of EAE, whereas overexpressing miR-1247 decreased the severity of the disease. Cytokine-regulated miR-1247 and miR-122 expression levels are inversely associated with pathogenic signatures of Th1 and Th17 cells between lymphoid and central nervous systems. Discussion: Our results suggest that miR-122 and miR-1247 act as peripheral brakes to CD4+ T cell pathogenicity that are overruled in the inflamed target organ. These findings may have important implications for autoimmune diseases.
- Dissection of the microRNA transcriptomes of CD4+ T cell subsets in autoimmune inflammation identifies novel regulators of disease pathogenesisPublication . Cunha, Carolina; Romero, Paula Vargas; Inácio, Daniel; Pais, Ana Teresa; Pelicano, Catarina; Costa, Marina; Mensurado, Sofia; Gonçalves-Sousa, Natacha; Papotto, Pedro H.; Neves, Daniel; Sobral, Daniel; Enguita, Francisco; Silva-Santos, Bruno; Gomes, AnitaMicroRNAs (miRNAs) are key regulators of CD4+ T cell differentiation, but how they contribute to the course of an autoimmune disease in vivo remains poorly studied. Given the known roles in autoimmunity of pro-inflammatory T helper 1 (Th)1 and Th17 cells, and anti-inflammatory Foxp3+ regulatory cells, we established a triple reporter mouse for Ifng, Il17 and Foxp3, and subjected it to experimental autoimmune encephalomyelitis (EAE) to characterize the miRNomes of the corresponding CD4+ T cell subsets. We identified 110 miRNAs differentially expressed between the pro-inflammatory (Th1 and Th17 cells) and the Treg cell subsets. Among these, we found novel functions for miR-122-5p and miR-1247 as regulators of Th17 cell proliferation and Th1 cell differentiation, thus impacting the course or severity of EAE, respectively. Importantly, their expression patterns suggest miR-122-5p and miR-1247 act as peripheral brakes to CD4+ T cell pathogenicity that are subverted in the inflamed central nervous system.
- microRNA-122 and microRNA-1247 regulate the pathogenic phenotype of effector CD4+ T cell subsets in (auto)immune responses in vivoPublication . Cunha, Carolina; Romero, Paula Vargas; Pelicano, Catarina; Pais, Ana Teresa; Inácio, Daniel; Papotto, Pedro; Sobral, Daniel; Amado, Tiago; Gomes, Anita Q.; Silva-Santos, BrunoAutoimmune diseases are often associated with an imbalance between CD4+ T cell subsets, namely pro-inflammatory effector cells, including T helper 1 (Th)1 and Th17 cells (IFN-γ- and IL-17-producers, respectively), and anti-inflammatory Foxp3+ regulatory cells (Treg). The differentiation of these distinct CD4+ T cell subsets is known to be regulated by microRNAs (miRNAs), small non-coding RNAs that fine-tune gene expression at the post-transcriptional level. While various individual miRNAs have been implicated in this process, a holistic approach focused on in vivo immune responses is missing to better understand how miRNA networks shape the CD4+ T cell compartment in pathophysiology. To address this biological question, we established a triple reporter mouse for Ifng, Il17, and Foxp3, and subjected it to experimental autoimmune encephalomyelitis (EAE), a widely used rodent model of Multiple Sclerosis (MS). We performed miRNA-seq analysis on Th1, Th17, and Treg cells isolated from the spleen and lymph nodes (LNs) at the peak-plateau stage of EAE, and found 110 miRNAs to be differentially expressed between the effector and regulatory subsets. From there, we studied the functional role of 5 candidate miRNAs as they were specifically upregulated in one population versus the others. In vivo miRNA modulation showed that silencing miR-122 (upregulated in Th17 cells) increased the frequency of IL-17A+ cells in the LNs and precipitated the onset of EAE, whereas upregulation of miR-1247 (highly expressed in the Th1 subset) decreased the severity of the disease reducing the number of IFN-γ+ cells in the LNs. We further found that both IL-6 and TGF-β induce miR-122 expression, whereas IL-23 and IL-1β repress its expression. Given that IL-23 and IL-1β are critical to induce Th17-mediated pathogenicity, our data suggests that miR-122 is expressed in a non-pathogenic context. Interestingly, we have observed a pathogenic gene signature in CNS-derived Th17 cells (when compared to peripheral Th17 cells) with concomitantly decreased levels of miR-122, suggesting that miR-122 may regulate Th17 pathogenicity. Similarly, we observed that once Th1 cells infiltrate the CNS, their levels of miR-1247 decrease, and they produce higher levels of IFN-γ. Furthermore, as we found that this miRNA is induced by the anti-inflammatory cytokines IL-10 and TGF-β, we propose that miR-1247 constitutes an auto-regulatory mechanism of Th1 cells in the periphery, which is disrupted upon CNS infiltration. Overall, our results suggest that miR-122 and miR-1247 control the pathogenic phenotype of effector Th17 and Th1 cells, respectively, during CNS autoimmunity. These findings may have important implications for autoimmune diseases, which we are now assessing in samples from MS patients.
- MicroRNA-146a controls functional plasticity in γδ T cells by targeting NOD1Publication . Schmolka, Nina; Papotto, Pedro H.; Romero, Paula Vargas; Amado, Tiago; Enguita, Francisco J.; Amorim, Ana; Rodrigues, Ana F.; Gordon, Katrina E.; Coroadinha, Ana S.; Boldin, Mark; Serre, Karine; Buck, Amy H.; Gomes, Anita Quintal; Silva-Santos, Brunoγδ T cells are major providers of proinflammatory cytokines. They are preprogrammed in the mouse thymus into distinct subsets producing either interleukin-17 (IL-17) or interferon-γ (IFN-γ), which segregate with CD27 expression. In the periphery, CD27- γδ (γδ27-) T cells can be induced under inflammatory conditions to coexpress IL-17 and IFN-γ; the molecular basis of this functional plasticity remains to be determined. On the basis of differential microRNA (miRNA) expression analysis and modulation in γδ T cell subsets, we identified miR-146a as a thymically imprinted post-transcriptional brake to limit IFN-γ expression in γδ27- T cells in vitro and in vivo. On the basis of biochemical purification of Argonaute 2-bound miR-146a targets, we identified Nod1 to be a relevant mRNA target that regulates γδ T cell plasticity. In line with this, Nod1-deficient mice lacked multifunctional IL-17+ IFN-γ+ γδ27- cells and were more susceptible to Listeria monocytogenes infection. Our studies establish the miR-146a/NOD1 axis as a key determinant of γδ T cell effector functions and plasticity.
- MicroRNA-146a controls IFN-g production and functional plasticity of murine gd T cells by targeting Nod1Publication . Schmolka, Nina; Papotto, Pedro H.; Romero, Paula Vargas; Amado, Tiago; Enguita, Francisco J.; Amorim, Ana; Gordon, Katrina E.; Boldin, Mark; Serre, Karine; Buck, Amy H.; Gomes, Anita Quintal; Silva-Santos, Brunoγδ T cells have emerged as key providers of the proinflammatory cytokines interleukin 17 (IL-17) and interferon-γ (IFN-γ) in various models of infection, inflammation, and autoimmunity. Our previous epigenetic and transcriptional analyses have shown that whereas CD27+ γδ T cells are committed to IFN-γ expression, the IL-17 producing CD27- subset has limited plasticity to co-express both cytokines under inflammatory conditions (Schmolka et al. Nat Immunol 2013). To further understand the molecular control of this plasticity we now investigated the potential role of microRNA (miRNA)-mediated post-transcriptional regulation.
- Role of microRNAs on T cell differentiation during immune responses in vivoPublication . Cunha, Carolina; Romero, Paula Vargas; Pelicano, Catarina; Pais, Ana Teresa; Inácio, Daniel; Pappoto, Pedro; Amado, Tiago; Silva-Santos, Bruno; Gomes, Anita Q.CD4+ T cells are key players in host defense against pathogens, but an incorrect balance between CD4+ T cell subsets, namely pro-inflammatory effector cells, including T helper 1 (Th)1 and Th17 cells (IFN-γ- and IL-17-producers, respectively), and anti-inflammatory regulatory cells (Treg; Foxp3+ subset), can lead to immune-mediated diseases. MicroRNAs (miRNAs) are small non-coding RNAs that negatively regulate gene expression at the post-transcriptional level. While individual miRNAs were shown to regulate the differentiation of specific CD4+ T cell populations, a holistic approach based on in vivo responses is missing and is critical to understanding how miRNA networks control this balance under physiological conditions. To address this, we have established a triple reporter mouse for Ifng, Il17, and Foxp3, and subject it to experimental autoimmune encephalomyelitis (EAE). We perform miRNA-seq analysis on Th1, Th17, and Treg cells isolated from the spleen (SPL) and lymph nodes (LNs) at the peak-plateau stage and found that 110 miRNAs are differentially expressed between effector and regulatory subsets. We further selected 8 candidate miRNAs that were specifically upregulated in one population versus the others. Both overexpression and inhibition studies showed that miR-126a limits IL-17+ expression in Th17 cells in vitro. Treatment with antagomiRs in vivo showed that silencing miR-122 increased the number of IL-17+ cells in the LNs and precipitated the onset of EAE, whereas inhibition of miR-1247 decreased the severity of the disease by reducing the number of IFN-γ+ cells, also in the LNs. Additionally, we identified IL-6 and TGF-β as the key cytokines upstream of miR-126a and miR-1247 expression, respectively. While both IL-6 and TGF-β also induce miR-122 expression, we found that IL-23 and IL-1β repress its expression. Interestingly, and given that IL-23 and IL-1β are critical to inducing Th17-mediated pathogenicity, we have consistently observed a pathogenic gene signature in CNS-derived Th17 cells when compared to peripheral Th17 cells with concomitantly decreased levels of miR-126a and miR-122. Overall, our results suggest that miR-126a and miR-122 regulate IL-17 expression and the pathogenic phenotype of Th17 cells to prevent excessive inflammation in the periphery while miR-1247 maintains the inflammatory phenotype of Th1 cells in an anti-inflammatory environment.