Targeted delivery of glycine receptors to excitable cells

Abstract

The invention provides a method of modulating electrophysiological activity of an excitable cell. The method involves causing exogenous expression of a glycine receptor (GlyR) protein in an excitable cell of a subject. Thereafter, the excitable cell is exposed to an allosteric modulator of the GlyR protein. Modulation of the exogenous GlyR protein (an ion channel) in response to the allosteric modulator modulates the electrophysiological activity of the excitable cell. The method can be used to control pain in a subject. The invention further provides a replication-defective HSV vector comprising an expression cassette encoding a GlyR protein, stocks and pharmaceutical compositions containing such vectors, and a transgenic animal.

1 . A method of modulating the electrophysiological activity of an excitable cell comprising causing exogenous expression of a glycine receptor (GlyR) protein in an excitable cell of a subject and subsequently exposing the excitable cell to an allosteric modulator of the GlyR protein. 
   
   
       2 . The method of  claim 1 , wherein the excitable cell is a peripheral neuron. 
   
   
       3 . The method of  claim 1  or  2 , which results in the attenuation of pain in the subject. 
   
   
       4 . A method of attenuating the sensation of pain in a subject, the method comprising causing exogenous expression of a GlyR protein in a peripheral neuron of a subject, wherein the peripheral neuron is associated with the sensation of pain, and subsequently exposing the peripheral neuron to an allosteric modulator of the GlyR protein, whereby the sensation of pain in the subject is attenuated in the subject. 
   
   
       5 . The method of any of  claims 1 - 4 , wherein exogenous expression of the GlyR protein is caused by introducing a genetic vector into the excitable cell, which vector comprises a nucleic acid encoding the GlyR protein in operable linkage to a promoter suitable for expressing the nucleic acid encoding the GlyR protein within the peripheral neuron. 
   
   
       6 . The method of any of  claims 1 - 5 , wherein the GlyR protein comprises an alpha 1 subunit of GlyR. 
   
   
       7 . The method of any of  claims 1 - 5 , wherein the GlyR protein comprises an alpha2 subunit of GlyR. 
   
   
       8 . The method of any of  claims 1 - 5 , wherein the GlyR protein comprises an alpha3 subunit of GlyR. 
   
   
       9 . The method of any of  claims 1 - 5 , wherein the GlyR protein comprises an alpha4 subunit of GlyR. 
   
   
       10 . The method of any of  claims 1 - 5 , wherein the GlyR protein comprises beta subunit of GlyR. 
   
   
       11 . The method of any of  claims 1 - 5 , wherein the wherein the GlyR protein comprises a mutein of a GlyR subunit. 
   
   
       12 . The method of  claim 11 , wherein the mutein is of the alpha1 subunit of GlyR. 
   
   
       13 . The method of  claim 11  or  12 , wherein the mutein converts the GlyR to a cationic channel. 
   
   
       14 . The method of  claim 11  or  12 , wherein the mutein lacks sites for zinc potentiation or zinc inhibition, anesthetic potentiation or affinity for ligands. 
   
   
       15 . The method of  claim 5 , wherein the genetic vector is a replication-defective HSV vector. 
   
   
       16 . The method of any of  claims 1 - 15 , wherein the allosteric modulator is an agonist of the GlyR protein. 
   
   
       17 . The method of  claim 16 , wherein the agonist is glycine. 
   
   
       18 . The method of any of  claims 1 - 17 , wherein the subject is human. 
   
   
       19 . A replication-defective HSV vector comprising an expression cassette encoding a GlyR protein. 
   
   
       20 . The vector of  claim 19 , wherein the GlyR protein comprises an alpha1 subunit of GlyR. 
   
   
       21 . The vector of  claim 19 , wherein the GlyR protein comprises an alpha2 subunit of GlyR. 
   
   
       22 . The vector of  claim 19 , wherein the GlyR protein comprises an alpha3 subunit of GlyR. 
   
   
       23 . The vector of  claim 19 , wherein the GlyR protein comprises an alpha4 subunit of GlyR. 
   
   
       24 . The vector of  claim 19 , wherein the GlyR protein comprises beta subunit of GlyR. 
   
   
       25 . The vector of  claim 19 , wherein the wherein the GlyR protein comprises a mutein of a GlyR subunit. 
   
   
       26 . The vector of  claim 25 , wherein the mutein is of the alpha1 subunit of GlyR. 
   
   
       27 . The vector of  claim 25  or  26 , wherein the mutein converts the GlyR to a cationic channel. 
   
   
       28 . The vector of  claim 25  or  26 , wherein the mutein lacks sites for zinc potentiation or zinc inhibition, anesthetic potentiation or affinity for ligands. 
   
   
       29 . A viral stock comprising the vector of any of  claims 19 - 28  having a titer of between about 10 6  plaque-forming units (pfu) and about 10 11  pfu. 
   
   
       30 . A pharmaceutical composition comprising the vector of any of  claims 19 - 28  and a pharmaceutically-acceptable carrier. 
   
   
       31 . The pharmaceutical composition of  claim 30 , formulated for injection. 
   
   
       32 . A transgenic animal comprising an exogenously expressed GlyR protein. 
   
   
       33 . The transgenic animal of  claim 32 , which is a mouse.