AB012. Transcriptional and chromatin profiling reveals the molecular architecture and druggable vulnerabilities of thymic epithelial tumors (TETs)

Thymic epithelial tumors (TETs) have been profiled to the present moment mainly through several analyses of FFPE samples. Despite the leap forward brought by the TCGA, several questions remain still unsolved. Among these, TETs are characterized by a strong component of immune infiltrate which makes the transcriptomic analyses conducted so far scarcely interpretable to profile stromal subpopulations constitutive of the tumor. Furthermore, rarely correspondent healthy tissue is available due to the lipomatous atrophy of aged thymi. Therefore, the recent report of (I) isolation, (II) propagation (III) and characterization of human thymic epithelial cells (TECs) and their capacity to reconstitute the functional organ ex vivo and in vivo, represents a novel approach to study the biology of both healthy and neoplastic thymi. Human thymic biopsies (both healthy and neoplastic) were digested and plated on a lethally irradiated murine feeder layer. Both RNA-Seq and CUTANDTAG were performed on cultivated TECs at different passages. Cultured TECs were injected with human thymic interstitial cells into rat decellularized scaffolds and cultivated for 10–12 days. sc-RNA Seq is currently being performed on both healthy and neoplastic thymic mini-organs and their correspondent primary tissues. Here show that we successfully cultivated a cohort of 21 clonogenic TECs in vitro including adult neoplastic TECs, their non-tumoral counterpart and pediatric TECs. We show that at the transcriptome level each class of TECs clusters independently and that neoplastic TECs belong to the same cloud independently from thymoma histotype. Around 1,400 differentially expressed genes (DEGs) can be found when comparing adult neoplastic and non-neoplastic counterpart, among which around 70 are transcription factors. Importantly, we prove for the first time that clonogenic TECs derived from TETs can repopulate a decellularized rat scaffold and recreate a 3D architecture mimicking the primary tumor. This work demonstrates that this culture system allows the expansion of clonogenic TECs from both tumor samples and their non-tumoral counterpart. Those cells, when transplanted into decellularized thymi, reproduce the architecture of the primary tissue, showing that TETs contain progenitor/stem epithelial cells. We are currently characterizing TECs at the transcriptomic and epigenomic level with aim of identifying new druggable targets prior to clinical trials

Reconstitution of a functional human thymus by postnatal stromal progenitor cells and natural whole-organ scaffolds.

The thymus is a primary lymphoid organ, essential for T cell maturation and selection. There has been long-standing interest in processes underpinning thymus generation and the potential to manipulate it clinically, because alterations of thymus development or function can result in severe immunodeficiency and autoimmunity. Here, we identify epithelial-mesenchymal hybrid cells, capable of long-term expansion in vitro, and able to reconstitute an anatomic phenocopy of the native thymus, when combined with thymic interstitial cells and a natural decellularised extracellular matrix (ECM) obtained by whole thymus perfusion. This anatomical human thymus reconstruction is functional, as judged by its capacity to support mature T cell development in vivo after transplantation into humanised immunodeficient mice. These findings establish a basis for dissecting the cellular and molecular crosstalk between stroma, ECM and thymocytes, and offer practical prospects for treating congenital and acquired immunological diseases

PROSPETTIVE DI SVILUPPO PER UNO STRUMENTO DI LETTURA INTEGRATA DEL MOSAICO PAESISTICO AMBIENTALE

The theme of landscape classification by homogeneous units was explored. The used approach considered what the different disciplines related to land management and planning process need and what indicators are most commonly used. A review of landscape classification methods adopted in several European countries and in Italy was done. Results showed high diversity for the used indicators, but also a general trend towards standardization of methodologies in order to link different scales of analysis. Experiences done at the national level has shown both a general lack for aspects relating to environmental quality, social and economic implications and the dominance of interest for the structural landscape components. In fact, morphological structure, spatial analysis based on land use, land use change, shape and size are the main parameters detected. The proposal of a new approach, based on the examination of the links between different disciplines subjects with the needs of knowledge the landscape complexity and the role of the possible conflicts and sinergies between them was formulate

I prati da sfalcio come elementi del paesaggio culturale: il caso di studio dell’area montana delle valli del Natisone (Udine)

Molto particolari sono i paesaggi culturali, risultato del forte adattamento dei processi antropici a specifiche condizioni ambientali che, poiché frutto di un equilibrio, è associato ad una condizione di sostenibilità nel lungo periodo. Con questo lavoro si vuole presentare i primi risultati di una ricerca che mira alla definizione di un approccio operativo utile alla caratterizzazione dei sistemi prativi ed alla conoscenza del loro livello di conservazione in un ambito di paesaggio culturale montano. I risultati evidenziano per alcune realtà un elevato stato di conservazione, manifestato dalla presenza di emergenze floristiche di notevole pregio. I prati di maggior interesse di solito ricadono nelle vicinanze dei nuclei abitativi, a testimonianza della stretta relazione tra le attività di gestione e la conservazione della qualità ambientale di queste cenosi. In particolare, emerge una forte correlazione tra il mantenimento degli sfalci, che interessano oramai poche realtà, e la ricchezza floristica rilevata nei prati studiati.In particolare la copertura delle specie indicatrici di cui sopra, aumenta in prati dislocati in aree lontane dai centri abitati, di piccola estensione e circondati dai boschi. In queste condizioni, le specie, si sviluppano maggiormente al margine boschivo e ricoprono una posizione ecotonale, fino a riversarsi nei prati. La mancanza dell’azione selettiva dello sfalcio ne favorisce la diffusione ed espansione, provocando un rapido deterioramento delle cotica