Tissue specific expression of antibodies in chickens

Abstract

Transgenes encoding exogenous antibodies are stably integrated into donor cells and are present in the somatic tissue of chimeric birds. The transgenes encode exogenous antibodies and are preferably expressed in the oviduct for collection in the egg. Tissue specificity is provided by selecting the content of the transgene accordingly. Birds whose genome is comprised of trangene-derived exogenous antibody-encoding DNA express exogenous antibodies having desirable chemical properties with increased therapeutic utility compared to antibodies derived from bacterial expression systems.

1 . A composition comprising monoclonal antibodies encoded by an exogenous polynucleotide and selectively expressed in tubular gland cells of a genetically modified chicken and collected in eggs laid by the chicken, wherein the antibodies are present in egg white at a concentration of at least 40 μg/ml.  
     
     
         2 . The composition of  claim 1  wherein the monoclonal antibodies contained in the egg are substantially free of fucosyl residues.  
     
     
         3 . The composition of  claim 1  wherein the mannose concentration is greater than approximately 40%.  
     
     
         4 . The composition of  claim 1  wherein the galactose concentration is less than approximately 2%.  
     
     
         5 . A method to produce a monoclonal antibody substantially free of fucosyl residues comprising: 
 expressing the antibody in tubular gland cells of a genetically modified chicken having an exogenous polynucleotide incorporated into a genome of the chicken; and    collecting the antibody from eggs laid by the chicken wherein the antibody is present in the egg white at a concentration of at least 40 μg/ml.    
     
     
         6 . The method of  claim 5  wherein the antibodies have a mannose concentration of greater than approximately 40%.  
     
     
         7 . The method of  claim 5  wherein the galactose concentration is less than approximately 2%.  
     
     
         8 . A genetically modified chicken expressing in tubular gland cells monoclonal antibodies encoded by an exogenous polynucleotide, wherein the monoclonal antibodies are present in egg white at a concentration of at least 40 μg/ml.  
     
     
         9 . The chicken of  claim 8  wherein the antibodies are substantially free of fucosyl residues.  
     
     
         10 . The chicken of  claim 8  wherein the mannose concentration is greater than approximately 40%.  
     
     
         11 . The chicken of  claim 8  wherein the galactose concentration is less than approximately 2%.  
     
     
         12 . A vector comprising a promoter linked to a heterologous coding sequence to express said coding sequence in tubular gland cells of an avian oviduct.  
     
     
         13 . The vector of  claim 12 , wherein said promoter is selected from the group consisting of an ovomucoid, ovalbumin, lysozyme, and ovomucin promoter.  
     
     
         14 . The vector of  claim 12 , further comprising a gene encoding a selectable marker.  
     
     
         15 . The vector of  claim 12 , further comprising an internal ribosome entry site element.  
     
     
         16 . The vector of  claim 12 , wherein the heterologous coding sequence encodes a human antibody.