ReTuBi Lecture - Ângela Gonçalves

On July 23 of 2018, Ângela Gonçalves from DKFZ (Germany) was the invited speaker as an expert visit with the lecture “Dissection of complex tissues with single-cell transcriptomics”. 

Summary of the Lecture:

Recent technological developments have made it possible to characterise the transcriptomes of thousands of single cells in a single experiment. In this presentation, I will outline some of the computational tools that we are developing to address opportunities and challenges of analysing these data. Subsequently, I will focus on using such techniques to dissect the composition of the human uterus and of menstrual fluid. I will show how we obtained maps of cell types in these tissues and insights into cell to cell communication in the fetal-maternal interface. 


ReTuBi Lecture - Floyd Romesberg

On July 20 of 2018,  Floyd Romesberg from The Scripps Research Institute (USA) was the invited speaker as an expert visit with the lecture “A Semi-synthetic organism that stores and retrieves increased genetic information". 


Summary of the Lecture:

Since the last common ancestor of all life on earth, the biological diversity has been encoded in a four letter, two base pair genetic alphabet. Expansion of the genetic alphabet to include a fifth and sixth letter than for a third, unnatural base pair not only has immediate utility for a number of applications, such as site-specific oligonucleotide labeling, but also serves as the foundation for an organism with an expanded genetic code. Toward this goal, we have examined a large number of different unnatural nucleotides bearing mainly hydrophobic nucleobase analogs that pair based on packing and hydrophobic interactions rather than H-bonding. Optimization based on extensive structure-activity relationship studies and two screens resulted in the identification of a class of unnatural base pairs that are well recognized by DNA and RNA polymerases. More recently, we have engineered E. coli to import the requisite unnatural triphosphates and shown that DNA containing the unnatural base pair is efficiently replicated, transcribed, and translated within the cell, resulting in the first semi-synthetic organism that stores and retreives increased information.


ReTuBi Lecture - Eliane Piaggio

On July 16 of 2018, Eliane Piaggio from Institut Curie (France) was the invited speaker as an expert visit with the lecture “High dimensional analysis of immune cells in breast tumor-draining lymph nodes”. 

Summary of the Lecture:

Lymph node (LN) invasion by tumor cells correlates with a negative clinical prognosis across different cancer types. It is thought that the metastatic tumor cells invading the LNs exert local immunosuppression, which promotes the loss of tumor immune control. To determine whether tumor-invaded LNs represent tolerogenic sites for T cells, we used a multiscale immune profiling strategy based on multiparametric high-dimensional flow cytometry, RNA sequencing, and T cell receptor (TCR) repertoire analysis, and more recently single-cell RNAseq coupled to TCRseq. We compared CD8+, CD4+ conventional and regulatory T cells in matched tumor-invaded LNs, non-invaded LNs, and primary tumors (TILs) from patients with luminal breast cancer. We found that regulatory T cells in all tissues express higher levels of both positive and negative immunecheckpoints than CD4+ and CD8+ T cells. The T cells in invaded LNs proliferate, produce cytokines, and respond to recall antigens, whereas TILs from the same patients fail to do so. Repertoire analysis shows that CD4+ and CD8+ T cells in LNs and tumors share oligoclonal TCRs, suggesting that tumor-specific T cells traffic between the two sites, but acquire the exhausted phenotype exclusively in tumors. Therefore, in contrast to TILs, tumor-specific T cells within invaded LNs are fully functional. These results suggest that LNs may represent a tumor immunoediting site in which immune-resistant tumor-cell clones are selected, in line with the strong prognosis value of invaded TDLNs for relapse.

Nuclear and mitochondria instability in health and cancer Scientific Symposium

From July 3 to 5, 2018 it was held the "Nuclear and mitochondria instability in health and cancer Scientific Symposium", in Montargil, Portugal. This ReTuBi event had a total of 31 participants from Instituto de Medicina Molecular, Institut Curie and from the Andalusian Molecular Biology and Regenerative Medicine Centre (CABIMER).

ReTuBi Lecture - Antonin Morillon

On July 2 of 2018, Antonin Morillon from Institut Curie (France) was the invited speaker as an expert visit with the lecture “The dark side of the genome: pervasive they said”. 

Summary of the Lecture:

Among the signals that control the epigenetic landscape, non-coding (nc)RNAs have been identified to play a major role but the generalization and the mechanisms of their activity are still poorly apprehended. Recent data using high-throughput technologies have profoundly changed our view on how the genomes are organized. Indeed transcriptome analyses have shown that large genomic regions are pervasively transcribed producing a broad variety of lncRNA which functions on the epigenome remain to be deciphered. Recent works showed that S. cerevisiae’s genome also supports production of non-coding protein large transcripts, which are strongly controlled by RNA decay pathways. Of specific interest are the lncRNA XUT that we described recently, mostly antisense to class II genes and associated with a consistent regulatory potential through epigenetic modifications. Here, I will present data providing insights on their regulatory activity which is conserved also in S. pombe containing RNAi pathway. The transcription and post-transcription-mediated regulatory activities of antisense transcripts will also be discussed in human cells where we draw an unprecedented landscape of antisense transcription in cancer cell lines and tumors.

Staff exchange between iMM-Curie (2018/06)

From June 25 to 30 of 2018 Marie Ouarné from Cláudio Franco (iMM) made a “ReTuBi Staff Exchange” to Danijela Vignjevic (Institut Curie) with the objectivo to observe the procedures and equipment necessary for surgery and intravital 2-photon imaging in brain of adult mice. This staff exchange was important to study polarization and migration profiles of endothelial cells in mice. It also enabled to study the influence of blood flow on endothelial cell behaviour and if possible replicated the techniques at the iMM, strengthening collaborations to study molecular pathways involved in endothelial response to blood flow.