Recent results of the searches for Supersymmetry in final states with one or two leptons at CMS are presented. Many Supersymmetry scenarios, including the Constrained Minimal Supersymmetric extension of the Standard Model (CMSSM), predict a substantial amount of events containing leptons, while the largest fraction of Standard Model background events -which are QCD interactions -gets strongly reduced by requiring isolated leptons. The analyzed data was taken in 2011 and corresponds to an integrated luminosity of approximately L = 1 fb −1 . The center-of-mass energy of the pp collisions was √ s = 7 TeV.

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Adeno-associated viral (AAV) vectors are a leading candidate for the delivery of CRISPR-Cas9 for therapeutic genome editing in vivo . However, AAV-based delivery involves persistent expression of the Cas9 nuclease, a bacterial protein. Recent studies indicate a high prevalence of neutralizing antibodies and T cells specific to the commonly used Cas9 orthologs from Streptococcus pyogenes (SpCas9) and Staphylococcus aureus (SaCas9) in humans. We tested in a mouse model whether pre-existing immunity to SaCas9 would pose a barrier to liver genome editing with AAV packaging CRISPR-Cas9. Although efficient genome editing occurred in mouse liver with pre-existing SaCas9 immunity, this was accompanied by an increased proportion of CD8 + T cells in the liver. This cytotoxic T cell response was characterized by hepatocyte apoptosis, loss of recombinant AAV genomes, and complete elimination of genome-edited cells, and was followed by compensatory liver regeneration. Our results raise important efficacy and safety concerns for CRISPR-Cas9-based in vivo genome editing in the liver.

Adeno-associated viral (AAV) vectors packaging the CRISPR-Cas9 system (AAV-CRISPR) can efficiently modify diseaserelevant genes in somatic tissues with high efficiency. AAV vectors are a preferred delivery vehicle for tissue-directed gene therapy because of their ability to achieve sustained expression from largely non-integrating episomal genomes. However, for genome editizng applications, permanent expression of nonhuman proteins such as the bacterially derived Cas9 nuclease is undesirable. Methods are needed to achieve efficient genome editing in vivo, with controlled transient expression of CRISPR-Cas9. Here, we report a self-deleting AAV-CRISPR system that introduces insertion and deletion mutations into AAV episomes. We demonstrate that this system dramatically reduces the level of Staphylococcus aureus Cas9 protein, often greater than 79%, while achieving high rates of on-target editing in the liver. Off-target mutagenesis was not observed for the self-deleting Cas9 guide RNA at any of the predicted potential off-target sites examined. This system is efficient and versatile, as demonstrated by robust knockdown of liver-expressed proteins in vivo. This self-deleting AAV-CRISPR system is an important proof of concept that will help enable translation of liver-directed genome editing in humans.

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Abstract, Von Willebrand factor (vWF) is a constitutive and specific component of endothelial cell (EC) matrix. In this paper we show that, in vitro, vWF can induce EC adhesion and promote organization of microfilaments and adhesion plaques. In contrast, human vascular smooth muscle cells and MG63 osteosarcoma cells did not adhere and spread on vWE Using antibodies to the/3 chains of fibronectin (~) and vitronectin (~3) receptors it was found that ECs adherent to vWF show clustering of both receptors. The/3, receptor antibodies are arranged along stress fibers at sites of extraceUular matrix contact while the /33 receptor antibodies were sharply confined at adhesion plaques. ECs release and organize endogenous fibronectin early during adhesion to vWE Upon blocking protein synthesis and secretion, ECs can equally adhere and spread on vWF but, while the ~3 receptors are regularly organized, the ~, receptors remain diffuse. This suggests that the organization of the/31 receptors depend on the release of fibronectin and/or other matrix proteins operated by the same cell. Antibodies to the ~3 receptors fully block EC adhesion to vWF and detach ECs seeded on this substratum. In contrast, antibodies to the ~ receptors are poorly active. Overall these results fit with an accessory role of ~ receptors and indicate a leading role for the ~3 receptors in EC interaction with vWF. To identify the EC binding domain on vWF we used monoclonal antibodies produced against a peptide representing the residues Glu1737-Ser175° of the mature vWF and thought to be important in mediating its binding to the platelet receptor glycoprotein IIb-IIIa. We found that the antibody that recognizes the residues 1,744-1,746, containing the Arg-Gly-Asp sequence, completely inhibit EC adhesion to vWF whereas a second antibody recognizing the adjacent residues 1,740-1,742 (Arg-GlyAsp-free) is inactive. Both antibodies do not interfere with EC adhesion to vitronectin. This defines the molecular domain on vWF that is specifically recognized by ECs and reaffirms the direct role of the Arg-GlyAsp sequence as the integrin receptor recognition site also in the vWF molecule.

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