CHARACTERIZATION OF A RECOMBINANT PLANT MONOCLONAL SECRETORY ANTIBODYAND PREVENTIVE IMMUNOTHERAPY IN HUMANS

A functional comparison was made between a monoclonal secretory antibo dy generated in transgenic plants and its parent murine IgG antibody. The affinity constants of both antibodies for a Streptococcus mutans a dhesion protein were similar. However the secretory antibody had a hig her functional affinity due to its dimeric structure. In the human ora l cavity, the secretory antibody survived for up to three days, compar ed with one day for the IgG antibody. The plant secretory antibody aff orded specific protection in humans against oral streptococcal coloniz ation for at least four months. We demonstrate that transgenic plants can be used to produce high affinity, monoclonal secretory antibodies that can prevent specific microbial colonization in humans. These find ings could be extended to the immunotherapeutic prevention of other mu cosal infections in humans and animals.