Abstract: The application relates to a chimeric receptor that targets CD33 and allows activation of the co-stimulatory pathway without binding the natural ligand. The application also relates to polynucleotides that encode the chimeric receptor, vectors, and host cells comprising the chimeric receptor. The application also relates to methods for preparing host cells comprising a chimeric antigen receptor in order to improve the in vivo persistence of the chimeric antigen receptor host cells.

Abstract: Compositions and methods are provided in embodiments directed to maintaining a desired concentration range of one or more drugs in a subject, and in particular embodiments to maintaining a desired drug concentration in a body compartment in a subject, based on the surprising discovery that antibodies persist in solution in body compartments such that antibody-antigen equilibrium principles can counteract drug clearance mechanisms. One or more antibodies are selected that have a dissociation constant KD that is similar to the desired drug concentration, wherein KD is independent of the affinity of the drug for a specific drug target (receptor) in the subject.

Abstract: Compositions and methods are provided in embodiments directed to maintaining a desired concentration range of one or more drugs in a subject, and in particular embodiments to maintaining a desired drug concentration in a body compartment in a subject, based on the surprising discovery that antibodies persist in solution in body compartments such that antibody-antigen equilibrium principles can counteract drug clearance mechanisms. One or more antibodies are selected that have a dissociation constant KD that is similar to the desired drug concentration, wherein KD is independent of the affinity of the drug for a specific drug target (receptor) in the subject.