Site Specific Modification of Adeno-Associated Virus Enables Both Fluorescent Imaging of Viral Particles and Characterization of the Capsid Interactome

Adeno-associated viruses (AAVs) are attractive gene therapy vectors due to their low toxicity, high stability, and rare integration into the host genome. Expressing ligands on the viral capsid can re-target AAVs to new cell types, but limited sites have been identified on the capsid that tolerate a peptide insertion. Here, we incorporated a site-specific tetracysteine sequence into the AAV serotype 9 (AAV9) capsid, to permit labelling of viral particles with either a fluorescent dye or biotin. We demonstrate that fluorescently labelled particles are detectable in vitro, and explore the utility of the method in vivo in mice with time-lapse imaging. We exploit the biotinylated viral particles to generate two distinct AAV interactomes, and identify several functional classes of proteins that are highly represented: actin/cytoskeletal protein binding, RNA binding, RNA splicing/processing, chromatin modifying, intracellular trafficking and RNA transport proteins. To examine the biological relevance of the capsid interactome, we modulated the expression of two proteins from the interactomes prior to AAV transduction. Blocking integrin αVβ6 receptor function reduced AAV9 transduction, while reducing histone deacetylase 4 (HDAC4) expression enhanced AAV transduction. Our method demonstrates a strategy for inserting motifs into the AAV capsid without compromising viral titer or infectivity

International Migration in the Atlantic Economy, 1850-1940

This chapter focuses on the economic analysis of what has been called the age of mass migration, 1850 to 1913, and its aftermath up to 1940. This has captured the interest of generations of economic historians and is still a highly active area of research. Here we concentrate on migration from Europe to the New World as this is where the bulk of the literature lies. We provide an overview of this literature focusing on key topics: the determinants of migration, the development of immigration policy, immigrant selection and assimilation, and the economic effects of mass migration as well as its legacy through to the present day. We explain how what were once orthodoxies have been revisited and revised, and how changes in our understanding have been influenced by advances in methodology, which in turn have been made possible by the availability of new and more comprehensive data. Despite these advances some issues remain contested or unresolved and, true to cliometric tradition, we conclude by calling for more research