Process for preparation of secretory IgA and secretory IgM

Abstract

A process for synthesizing and separating secretory IgA from a mixture of IgA monomer and IgA dimer is provided. The process includes covalently binding affinity tagged or epitope tagged recombinant secretory component to the IgA dimer in the mixture and binding the affinity tagged or an epitope tagged secretory IgA to immobilized moieties on the solid phase support resin to which the affinity tag or epitope tag binds and then eluting the affinity tagged or an epitope tagged secretory IgA with release buffer. A process for synthesizing and separating secretory IgM from a mixture of IgM and other plasma proteins is also provided. The process includes covalently binding affinity tagged or an epitope tagged recombinant secretory component to the IgM in the mixture and binding the affinity tagged or an epitope tagged secretory IgM to immobilized moieties on the solid phase support resin and then eluting the peptide tagged secretory IgM with a release buffer.

The invention claimed is: 
     
       1. A process for synthesizing a secretory IgM therapeutic by separating a pentameric IgM including J chain and mixed with other proteins in a protein mixture comprising:
 adding secretory component in solution that is tagged with an affinity or epitope tag selected from the group consisting of polyhistidine, AviTag, calmodulin-tag, FLAG-tag, hemaglutinin-tag, Myc-tag, S-tag, SBP-tag, Softag 1, Softag 3, V5 tag, Xpress tag, biotin carboxyl carrier protein, glutathione-S-transferase-tag, green fluorescent protein-tag, maltose binding protein-tag, Nus-tag; Strep-tag, thioredoxin-tag; TC tag, and Ty tag; to the protein mixture, the protein mixture containing the pentameric IgM including the J chain, facilitating the covalent binding of the affinity or epitope tagged secretory component to the pentameric IgM to produce the secretory IgM therapeutic; 
 exposing the protein mixture to a binding moiety immobilized on a solid phase resin under conditions that the secretory IgM therapeutic binds to the solid phase resin by interaction between the affinity or epitope tagged secretory component and the binding moiety; 
 washing the unbound protein mixture less the secretory IgM therapeutic from the solid phase support; and 
 then eluting the secretory IgM therapeutic with a release buffer from the solid phase support by the release buffer interfering with the interaction between the affinity or epitope tagged secretory component and the binding moiety. 
 
     
     
       2. The process of  claim 1  wherein the secretory component is human. 
     
     
       3. The process of  claim 1  wherein the affinity or epitope tag is removed from secretory IgM after the eluting step. 
     
     
       4. The process of  claim 1  wherein the moiety on the solid phase support resin to which the affinity or epitope tag binds is a divalent cation. 
     
     
       5. The process of  claim 1  wherein the secretory component is recombinant. 
     
     
       6. The process of  claim 1  wherein the affinity or epitope tag is a polyhistidine. 
     
     
       7. The process of  claim 1  wherein IgA has been removed from the plasma protein mixture before the epitope or affinity tagged secretory component is added. 
     
     
       8. The process of  claim 1  further comprising stabilizing the secretory IgM therapeutic by adding human serum albumin. 
     
     
       9. A process for synthesizing a secretory IgM therapeutic by separating pentameric IgM including J chain and mixed with other proteins comprising:
 adding secretory component in solution that is tagged with an affinity or epitope tag selected from the group consisting of polyhistidine, AviTag, calmodulin-tag, FLAG-tag, hemaglutinin-tag, Myc-tag, S-tag, SBP-tag, Softag 1, Softag 3, V5 tag, Xpress tag, biotin carboxyl carrier protein, glutathione-S-transferase-tag, green fluorescent protein-tag, maltose binding protein-tag, Nus-tag; Strep-tag, thioredoxin-tag; TC tag, and Ty tag; to the protein mixture, the protein mixture obtained from human plasma containing the pentameric IgM including the J chain, facilitating the covalent binding of the affinity or epitope tagged secretory component to the pentameric IgM containing the J chain to produce the secretory IgM therapeutic; 
 exposing the protein mixture to a binding moiety immobilized on a solid phase resin under conditions that the secretory IgM therapeutic binds to the solid phase resin by interaction between the affinity or epitope tagged secretory component and a binding moiety; 
 washing the unbound protein mixture less the secretory IgM therapeutic from the solid phase support; and 
 then eluting the secretory IgM therapeutic with a release buffer from the solid phase support by the release buffer interfering with the interaction between the affinity or epitope tagged secretory component and the binding moiety. 
 
     
     
       10. An improved process for synthesizing a secretory IgM therapeutic from a protein mixture of plasma proteins containing plasma derived IgM containing J chain, by adding secretory component that is tagged with an affinity or epitope tag to the protein mixture forming the secretory IgM therapeutic in the protein mixture wherein the improvement comprises: recovering the secretory IgM therapeutic from the protein mixture by adhesion to moieties on a solid phase support resin to which the affinity or epitope tag binds, and subsequent eluting the secretory IgM therapeutic using an elution buffer. 
     
     
       11. The improved process of  claim 10  wherein the secretory component is human. 
     
     
       12. The improved process of  claim 10  wherein the protein mixture is obtained from human plasma. 
     
     
       13. The improved process of  claim 10  wherein the affinity or epitope tag is removed from the secretory IgM therapeutic prior to administration to a patient. 
     
     
       14. The improved process of  claim 10  wherein the moieties on the solid phase support resin to which the affinity or epitope tag binds is a divalent cation. 
     
     
       15. The improved process of  claim 10  further comprising washing unbound plasma proteins including unbound immunoglobulins lacking the J chain through the resin prior to the eluting the secretory IgM therapeutic. 
     
     
       16. The improved process of  claim 10  wherein the secretory component is recombinant. 
     
     
       17. The improved process of  claim 10  wherein the affinity or epitope is histidine or polyhistidine and is coupled to the secretory component in vitro. 
     
     
       18. The improved process of  claim 10  wherein the plasma derived IgM containing J chain is pentameric IgM.