DECEMBER 1998 NEWS

Effective Monoclonal Antibodies Produced Successfully from Plants

December 9, 1998

In the latest issue of the journal Nature Biotechnology, Johns Hopkins University researcher Kevin Whaley and collaborators show that a monoclonal antibody purified from plant tissue is just as stable and efficacious as the same antibody expressed in mammalian cell culture. According to the report, soybean plants produce large amounts of therapeutic proteins at low cost and high yield, but it has not been clear whether these proteins work as well as those produced from mammalian cells.

Whaley demonstrated that a soybean-derived antibody directed against herpes simplex virus 2 (HSV-2) is equally effective as a mammalian antibody for protecting mice against genital herpes.

Because plant cells differ from mammalian cells in their ability to add sugars to proteins, it has been suggested plant-derived proteins might not make good human therapeutics. Whaley and his coauthors decided to test this by characterizing and comparing the physical properties of a humanized anti HSV-2 monoclonal antibody derived from either soybean or mammalian cells. They found that soybean-derived antibodies are comparable in terms of their ability to remain stable in human reproductive fluids, diffuse in cervical mucus, and protect mice against HSV-2 infection. They also reported that the affinity of the plant monoclonal for HSV did not differ from that of the mammalian expressed antibody, and there was no apparent difference in their ability to neutralize HSV-2.

The results support the feasibility of using plant-derived human therapeutics to treat sexually transmitted and other diseases. Animal-derived antibodies are both expensive to produce and controversial in origin. Scientists, animal welfare groups, and regulatory agencies increasingly are questioning the production of monoclonal antibodies from animals and urging the use of alternatives.

For a copy of the full article, contact Angela Atkins at Nature Biotechnology by fax at (212) 696-9006 or e-mail: a.atkins@natureny.com.

Refer to "Plantibodies make the grade" (research paper pp 1361-1363).