No tumour-initiating risk associated with scAAV transduction in newborn rat liver

International audienceDelivery of recombinant adeno-associated virus (rAAV) vectors to the newborn liver is followed by a rapid loss of episomal vector copies because of hepatocyte proliferation. In selected hepatocytes, integration of rAAV genomes can lead to a sustained expression of the transgene. The safety of in vivo gene therapy with single-stranded AAV vectors has been questioned in a study reporting a high incidence of hepatocellular carcinoma, associated with provirus integration events in mice that receive an single-stranded AAV injection at birth. To investigate the tumour-initiating potential of the newly established self-complementary AAV (scAAV) vectors in the liver, groups of newborn rats received intravenous injection of a scAAV vector encoding the green fluorescent protein (GFP), or were injected with phosphate-buffered saline (PBS) or diethylnitrosamine (DEN), a well-known liver tumour initiator. The rats were fed on a diet containing 2-acetylaminofluorene, a potent liver tumour-promoting agent to accelerate the carcinogenic process. After 2 months, the animals were killed and their livers analysed. Preneoplastic nodules were identified by glutathion S-transferase-p (GSTp) staining, and GFP expression was detected by immunohistochemistry. Vector genome integration events were analysed. The numbers of GSTp-positive foci were comparable in the PBS and the scAAV-GFP groups and significantly higher in the DEN group. The proportion of GSTp-positive foci that also expressed GFP was low and in the range expected for random occurrence. No specific integration hot spots were detected by linear amplification-mediated-PCR in transduced liver. In conclusion, scAAV transduction of newborn rat liver does not trigger preneoplastic lesions suggesting an absence of liver tumourigenesis

Alveolar macrophages are epigenetically altered after inflammation, leading to long-term lung immunoparalysis (vol 21, pg 636, 2020)

An amendment to this paper has been published and can be accessed via a link at the top of the paper

Agonist anti-ChemR23 mAb reduces tissue neutrophil accumulation and triggers chronic inflammation resolution

International audienceResolution of inflammation is elicited by proresolving lipids, which activate GPCRs to induce neutrophil apoptosis, reduce neutrophil tissue recruitment, and promote macrophage efferocytosis. Transcriptional analyses in up to 300 patients with Inflammatory Bowel Disease (IBD) identified potential therapeutic targets mediating chronic inflammation. We found that ChemR23, a GPCR targeted by resolvin E1, is overexpressed in inflamed colon tissues of severe IBD patients unresponsive to anti-TNF alpha or anti-alpha 4 beta 7 therapies and associated with significant mucosal neutrophil accumulation. We also identified an anti-ChemR23 agonist antibody that induces receptor signaling, promotes macrophage efferocytosis, and reduces neutrophil apoptosis at the site of inflammation. This ChemR23 mAb accelerated acute inflammation resolution and triggered resolution in ongoing chronic colitis models, with a significant decrease in tissue lesions, fibrosis and inflammation-driven tumors. Our findings suggest that failure of current IBD therapies may be associated with neutrophil infiltration and that ChemR23 is a promising therapeutic target for chronic inflammation

Concerted BAG3 and SIRPα blockade impairs pancreatic tumor growth

The BAG3- and SIRPα- mediated pathways trigger distinct cellular targets and signaling mechanisms in pancreatic cancer microenvironment. To explore their functional connection, we investigated the effects of their combined blockade on cancer growth in orthotopic allografts of pancreatic cancer mt4–2D cells in immunocompetent mice. The anti-BAG3 + anti-SIRPα mAbs treatment inhibited (p = 0.007) tumor growth by about the 70%; also the number of metastatic lesions was decreased, mostly by the effect of the anti-BAG3 mAb. Fibrosis and the expression of the CAF activation marker α-SMA were reduced by about the 30% in animals treated with anti-BAG3 mAb compared to untreated animals, and appeared unaffected by treatment with the anti-SIRPα mAb alone; however, the addition of anti-SIRPα to anti-BAG3 mAb in the combined treatment resulted in a > 60% (p < 0.0001) reduction of the fibrotic area and a 70% (p < 0.0001) inhibition of CAF α-SMA positivity. Dendritic cells (DCs) and CD8+ lymphocytes, hardly detectable in the tumors of untreated animals, were modestly increased by single treatments, while were much more clearly observable (p < 0.0001) in the tumors of the animals subjected to the combined treatment. The effects of BAG3 and SIRPα blockade do not simply reflect the sum of the effects of the single blockades, indicating that the two pathways are connected by regulatory interactions and suggesting, as a proof of principle, the potential therapeutic efficacy of a combined BAG3 and SIRPα blockade in pancreatic cancer

Coherence vs. Conferred Powers? The Case of the European External Action Service

The process of European integration has led to the creation of numerous external actions at the Union level, and these should now be brought together to reinforce the coherence of EU foreign affairs. The attainment of coherence finds an apparently insurmountable obstacle in the delimitation of the powers conferred on EU institutions, since a rigid separation of the powers of Union bodies hinders the generation of positive connections among EU policies. The Lisbon Treaty sought to increase coherence in foreign affairs in part by creating the European External Action Service. This paper examines the EEAS’s mandate and responsibilities in order to elucidate the interplay of coherence and conferred powers in external relations law. The first part of the analysis investigates the EEAS mandate, showing that the Treaties require the Service to coordinate external relations in order to ensure coherence. The second part examines the nature of this coordination, focusing on the technique legislators used to enable the EEAS to have a role in the implementation of development aid. Legislators identified the EEAS’s responsibilities by balancing the principle of the coherence of external action against the delimitation of conferred powers, with a view to fostering synergy in foreign affairs. It is argued that a similar approach can also be adopted in other areas where the EEAS brings added value as a coordinator, and in particular in the area of crisis response. An enlargement of the EEAS’s responsibilities is politically difficult, but it may be simplified by an amendment of the Treaties (where the mandate of the Service is spelled out), in such a way as to reinforce the Service’s legitimacy and effectiveness as a foreign-policy coordinator