Cell line, system and method for optical-based screening of ion-channel modulators

Abstract

A variety of applications, systems, methods and constructs are implemented for use in connection with screening of ion-channel modulators. Consistent with one such system, drug candidates are screened to identify their effects on cell membrane ion channels and pumps. The system includes screening cells having light responsive membrane ion switches, voltage-gated ion switches and fluorescence producing voltage sensors. A chemical delivery device introduces the drug candidates to be screened. An optical delivery device activates the light responsive ion switches. An optical sensor monitors fluorescence produced by the voltage sensors. A processor processes data received from the optical sensor. A memory stores the data received from the optical sensor.

1 . A modified cell line derived from parental cell line 293T, wherein the modified cell line comprises:
 voltage-gated ion channels; and   light-responsive ion switches that mediate depolarization from activation of the voltage-responsive ion channels.   
     
     
         2 . The cell line of  claim 1 , wherein the ion switches are ChR2 ion channels. 
     
     
         3 . The cell line of  claim 1 , wherein the ion switches are NpHR ion pumps. 
     
     
         4 . The cell line of  claim 1 , wherein the voltage-gated ion channels are Ca2+ channels. 
     
     
         5 . The cell line of  claim 1 , wherein the modified cell line further possesses the properties of genetically-encoded ion indicators. 
     
     
         6 . The cell line of  claim 5 , wherein the genetically-encoded ion indicators are calcium indicators 
     
     
         7 . A system for screening drug candidates to identify their effects on cell membrane ion channels and pumps, comprising:
 screening cells having light responsive membrane ion switches, voltage-gated ion switches and fluorescence producing voltage sensors;   a chemical delivery device for introducing the drug candidates to be screened;   an optical delivery device to activate the light responsive ion switches;   an optical sensor to monitor fluorescence produced by the voltage sensors;   a processor to process data received from the optical sensor; and   memory for storing the data received from the optical sensor.   
     
     
         8 . The system of  claim 7 , wherein the light responsive membrane ion switches are ChR2 ion channels. 
     
     
         9 . The system of  claim 7 , wherein the light responsive membrane ion switches are NpHR ion pumps. 
     
     
         10 . The system of  claim 7 , wherein the voltage-gated ion switches are Ca2+ channels. 
     
     
         11 . The system of  claim 7 , wherein the fluorescence producing voltage sensors are genetically-encoded calcium dye indicators. 
     
     
         12 . The system of  claim 7 , further comprising an array of wells each containing a portion of the screening cells and an array of optical sensors for detecting light from respective wells from the array of wells. 
     
     
         13 . A method for screening drug candidates to identify their effects on cell membrane ion channels and pumps, the method comprising:
 introducing a drug candidate to be screened to cells having light responsive membrane ion switches, voltage gated ion switches and fluorescence producing voltage sensors;   activating the light responsive membrane ion switches by generating light pulses;   detecting fluorescence produced by the voltage sensors;   processing data received from the optical sensor to identify changes in the cells electrical properties; and   storing the processed data received from the optical sensor.   
     
     
         14 . The method of  claim 13 , wherein the light responsive membrane ion switches are ChR2 ion channels. 
     
     
         15 . The method of  claim 13 , wherein the light responsive membrane ion switches are NpHR ion pumps. 
     
     
         16 . The method of  claim 13 , wherein the voltage-gated ion switches are Ca2+ channels. 
     
     
         17 . The method of  claim 13 , wherein the fluorescence producing voltage sensors are genetically-encoded calcium dye indicators. 
     
     
         18 . The method of  claim 13 , further comprising introducing a plurality of drug candidates to respective wells of an array of wells that each contain a portion of the screening cells and detecting light from respective wells from the array of wells using an array of optical sensors for detecting light. 
     
     
         19 . (canceled)