Patent ID: 7625718

Claim:
A method of screening an agent, conjugate, or conjugate moiety for capacity to be transported through the blood brain barrier in order to treat or diagnose a disease, comprising: (a) providing a cell expressing the sodium-dependent vitamin C transporter type 2 (SVCT2), wherein the SVCT2 transporter is the protein encoded by SEQ ID NO: 1 or has at least 90% sequence identity to the protein encoded by SEQ ID NO: 1, and the SVCT2 transporter can transport ascorbic acid, the SVCT2 transporter being situated in the plasma membrane of the cell expressing the SVCT2 transporter; (b) contacting the cell expressing the SVCT2 transporter with an agent, conjugate, or conjugate moiety; (c) determining the V max of the agent, conjugate or conjugate moiety for the SVCT2 transporter; (d) modifying the agent, conjugate or conjugate moiety; and (e) determining the V max of the modified agent, modified conjugate or modified conjugate moiety for the SVCT2 transporter; (f) providing a cell expressing the SVCT2 transporter and at least one efflux transporter or a cell expressing at least one efflux transporter, wherein the at least one efflux transporter is selected from the group consisting of the P-glycoprotein transporter, the multidrug resistance protein transporter, and the breast cancer resistance protein transporter; (g) contacting the cell expressing the SVCT2 transporter and at least one efflux transporter or the cell expressing at least one efflux transporter with the agent, conjugate, or conjugate moiety; and (h) determining that the agent, conjugate, or conjugate moiety is transported by the at least one efflux transporter; and determining the V max of the agent, conjugate or conjugate moiety for the efflux transporter; and determining the V max of the modified agent, modified conjugate or modified conjugate moiety for the efflux transporter; (i) comparing the ratio of the V max for the SVCT2 transporter to the V max for the efflux transporter for the agent, conjugate, or conjugate moiety with the ratio of the V max for the SVCT2 transporter to the V max for the efflux transporter for the modified agent, modified conjugate, or modified conjugate moiety; an increased ratio of the V max for the SVCT2 transporter to the V max for the efflux transporter for the modified agent, modified conjugate, or modified conjugate moiety demonstrates that the modification improves the capacity of the agent, conjugate, or conjugate moiety to be transported through the blood brain barrier; wherein: the agent is a neuropharmaceutical agent or an imaging component; and the conjugate comprises an agent that is a neuropharmaceutical agent or an imaging component.