PRODUCTION OF SECRETORY IMMUNOGLOBULIN-A BY A SINGLE MAMMALIAN-CELL

Secretory IgA (sIgA) plays a critical role in providing protection aga inst infection al the mucosal surfaces. Normally, sIgA is the product of two different cell types with heavy, light, and J chains produced b y the plasma cells, whereas secretory component (SC), a cleavage produ ct of the polymeric immunoglobulin receptor (pIgR), is added during th e transit of dimeric IgA through the epithelial cell layer, Ln the cur rent study, by introducing a gene for the processed form of SC into a cell line that produces dimeric IgA, we have succeeded in creating a s ingle cell that is able to produce and secrete covalently joined sIgA, To our knowledge, this is the first time it has been possible to effi ciently produce large quantities of sIgA of defined specificity in mam malian cells. The sIgA made using this approach has great potential as an immunotherapeutic.