FRAMINGHAM, Mass., Jan. 13 /PRNewswire/ -- Genzyme Transgenics Corporation (Nasdaq: GZTC) announced today that it has achieved high-level expression of a malaria antigen in the milk of transgenic mice. The antigen was expressed as part of Genzyme Transgenics' collaboration with the National Institute of Allergy and Infectious Diseases (NIAID) for the production of transgenic recombinant malarial proteins for use as malaria vaccines.
Although malarial parasite genes can be expressed in other recombinant systems, they
are produced in very limited quantities or in forms that may not induce the necessary
immune response. To express the MSP-1 antigen at high quantities, it was necessary to
change its gene sequence significantly without altering the protein itself. By extensively
changing portions of the nucleotide sequence of the gene, while leaving the amino acid
sequence intact, Genzyme Transgenics' scientists expressed the antigen in the milk of
transgenic mice at 2-4 mg./ml. and in cell culture. In contrast, the natural (wild-type) gene
was not expressed at all. The transgenically-produced recombinant MSP-1 antigen
produced in mouse milk was identified by its reaction with antibodies to MSP-1.
Malaria results from infection with the malarial parasite introduced into the bloodstream via the bite
of an infected mosquito. The World Health Organization (WHO) has estimated that 300-500
million people are infected worldwide, and one to two million die annually of the disease, 25
percent of them young children. Mosquitoes that transmit the disease have become resistant to
insecticides, and the most lethal form of the parasite, P. falciparum, has become resistant to the
major drug used to treat the disease, chloroquine. It is widely recognized that development of an
effective malaria vaccine would constitute a significant global public health advance.
"A major problem in developing MSP-1 as a vaccine has been the difficulty of expressing it in
properly processed forms and in quantities sufficient to make vaccine production feasible," said
James A. Geraghty, president and chief executive officer of Genzyme Transgenics. "We are
pleased to be able to support the NIAID and other health care organizations in meeting this
important medical need."
Genzyme Transgenics Corporation has filed a patent application for technologies related to the
expression of the MSP-1 protein and similar genes, and has signed a letter of intent to enter into a
Collaborative Research and Development Agreement (CRADA) with the NIAID, part of the
National Institutes of Health.
MSP-1 is a protein associated with the merozoite stage of the malaria life cycle. During this stage,
or the "blood stage" of the disease, merozoite organisms multiply in red blood cells of infected
individuals, eventually bursting them, then continue to infect other red blood cells.
Individuals infected with malaria develop antibodies against MSP-1. Studies have linked immunity
to MSP-1 acquired through infection with a lessening in disease severity. In experimental systems,
immunization with purified MSP-1 prepared from the parasites and some recombinant fragments
of this protein have also induced protection.
Genzyme Transgenics Corporation applies transgenic technology to enable the development and
production of recombinant proteins and monoclonal antibodies for medical uses. The company's
contract research organization businesses provide preclinical development and testing services to
pharmaceutical, biotechnology, medical device, and other companies. Genzyme Transgenics is also
developing idiotypic vaccines in collaboration with the National Cancer Institute. Genzyme
Corporation owns approximately 43 percent of the outstanding stock of Genzyme Transgenics and
has allocated these shares to Genzyme General.
This news release contains forward-looking statements about the potential in vivo immunogenicity
of transgenically-produced MSP-1 protein, its use as a malaria vaccine, the potential market for a
malaria vaccine, and the ability of Genzyme Transgenics Corporation to produce it in sufficient
quantities.
Actual results may differ materially from any projections that are not historical facts, and depend
on the timing and content of decisions made by the U.S. Food and Drug Administration.
Genzyme's releases are on the World Wide Web at genzyme.com. They are also
available from Genzyme's fax-on-demand service at 1-800-436-1443 within the United States or
1-201-1080 outside the United States. SOURCE Genzyme Transgenics Corporation |
