The present invention relates to a novel Hepatitis B virus (HBV) and/or Hepatitis D virus (HDV) receptor and its use for the development of cells, cell lines and non-human animals that are susceptible to HBV and/or HDV infection and can be used for immunological studies and/or for the screening of drugs, post-entry restriction factors and host dependency factors. It further relates to the use of the receptor for the identification of compounds useful in the treatment of HBV and/or HDV infection.

Provided here are certain recombinant HIV compositions and animal models to evaluate prophylactic and therapeutic antiviral compositions.

Modified non-human mammalian hepatoma cell lines that express hepatitis C virus (HCV) antigens and which are capable of generating tumours in a syngeneic animal model are provided. The cell lines are generated by genomic integration of an expression construct that comprises one or more HCV antigen-encoding sequences under the control of a constitutive promoter. The expression construct further comprises a selectable marker and a reporter gene under the control of the same promoter. The cell lines are useful for testing prophylactic and therapeutic vaccines against HCV either in vitro or in vivo.

Genetically modified non-human animals expressing human EPO from the animal genome are provided. Also provided are methods for making non-human animals expressing human EPO from the non-human animal genome, and methods for using non-human animals expressing human EPO from the non-human animal genome. These animals and methods find many uses in the art, including, for example, in modeling human erythropoiesis and erythrocyte function; in modeling human pathogen infection of erythrocytes; in in vivo screens for agents that modulate erythropoiesis and/or erythrocyte function, e.g. in a healthy or a diseased state; in in vivo screens for agents that are toxic to erythrocytes or erythrocyte progenitors; in in vivo screens for agents that prevent against, mitigate, or reverse the toxic effects of toxic agents on erythrocytes or erythrocyte progenitors; in in vivo screens of erythrocytes or erythrocyte progenitors from an individual to predict the responsiveness of an individual to a disease therapy.

The invention provides a method of increasing blood flow or perfusion in an ischemic tissue; inducing angiogenesis, neovascularization or revascularization; increasing skeletal muscle viability; promoting ischemic skin wound healing; treating or preventing gangrene; and/or treating CLI. In various aspects, the method comprises administering to a subject a hybrid adenoassociated virus (AAV) comprising a nucleotide sequence encoding an E-selectin, AAV serotype 2 (AAV2) inverted terminal repeats (ITRs), and a capsid from an AAV other than serotype 2. In various aspects, the method comprises administering to the subject a cell comprising an AAV comprising a nucleotide sequence encoding an E-selectin, AAV2 ITRs, and a AAV2 capsid.

Provided herein are methods and compositions for the production of hepatocytes from placenta stem cells. Further provided herein is the use of such hepatocytes in the treatment of, and intervention in, for example, trauma, inflammation, and degenerative disorders of the liver. Also provided herein are compositions and methods relating to combinations of nanofibrous scaffolds and adherent placental stem cells and methods of using the same in cartilage repair. Finally, provided herein are compositions and methods relating to nonadherent, CD34.sup.+CD45.sup. stem cells from placenta.

Genetically modified mice and methods and compositions for making and using the same are provided, wherein the genetic modification comprises humanization of an FcRI protein.

Provided herein is an animal model system and uses thereof. In particular, provided herein is an animal model for Neisseria infection and use of such a model in research and screening applications.

The following discloses a novel model for parasitic worm infection, which is useful for screening for and evaluating the efficacy of antiparasitic agents. In particular, the disclosure provides an immunocompromised mouse model that, for the first time, supports advanced development of Dirofilaria immitis (Di) parasites outside of their definitive hosts. As described herein, early-stage larval forms of Di, the causative agent of Canine Heartworm disease, not only persist in this model, but they develop into mature worms.

In one aspect, the invention relates to a method of loading exosomes with oligonucleotide cargo, by incubating an oligonucleotide comprising one or more hydrophobic modifications with a population of exosomes for a period of time sufficient to allow loading of the exosomes with the oligonucleotide. Exosomes loaded with hydrophobic ally modified oligonucleotide cargo, and uses thereof, are also provided.