Chinese scientists announced on Monday that they have bred a genetically altered cow capable of producing cancer fighting proteins for humans.
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The cow, which can produce CD20 antibodies in its milk, was born in Beijing on August 2 and a dozen more are due to be born next month. |
The cow, which can produce CD20 antibodies in its milk, was born in Beijing on Aug. 2 and a dozen more are due to be born next month.
Researchers said mass breeding of the animal would enable China to mass produce the therapeutic proteins cheaply.
The human monoclonal (produced from a single cell) antibodies could be purified from the milk of the transgenic cow, and used to treat B cell lymphomas and leukemias and some auto-immune diseases, said research team leader Li Ning, an academician with China Academy of Engineering.
"After 10 days of careful observation, we are happy to see the cow is very healthy," said Li, whose laboratory is based in the China Agriculture University.
The calf weighed 38 kg at birth. In seven to eight months, the research team would induce lactation to test its antibody expression.
The development is expected to significantly lower the costs of CD20 antibody production, which currently uses chimeric anti-CD20 CHO (Chinese hamster ovary) cells.
The low antibody expression level and high cost of cell culture has been a stumbling block in the industrial production of the antibody drug, which was approved by the US Food and Drug Administration in 1997.
CD20 cell-surface proteins found in mature B cells become cancerous in patients who suffer from non-Hodgkins lymphoma, which accounts for about 40 percent of all new cases of lymphoma. It is identified as the target in the treatment of lymphomas.
"The objective of our research is to make the transgenic animal express the antibody at high levels," said Li, adding that transgenic mice had been able to express 10 mg/ml of CD20 antibody on average in tests.
The US-based Business Communication Corp. has estimated the worldwide market for transgenically sourced therapies at more than US$1 billion in 2008, and 18.6 billion dollars by 2013.
Li said his group planned to complete the clinical study of the first functional food with the antibody in three years, and apply for production authorization from China's food and drug authorities, and the first functional drug could be expected in five years.
(Xinhua News Agency August 12, 2008)