A new vaccine headed for market protects cattle against the pneumonia-causing bacterium Pasteurella haemolytica. Pneumonia caused by this bacterium costs U.S. and Canadian cattle growers more than $1 billion annually. At the heart of the new vaccine is the world's first genetically engineered strain of P. haemolytica, produced by ARS researchers. The new vaccine could be marketed next year. Meanwhile, the researchers have already tackled their next task: a single vaccine that protects against the bad-news bacterial trio--P. haemolytica, P. multicoda and Haemophilus somnus. (PATENT APPLICATION 08/162392)
National Animal Disease Center, Ames, IA
Robert E. Briggs/Fred M. Tatum, (515) 239-8280

The problem: Parasites called coccidia commandeer the very cells that a chicken's immune system produces to kill them, leaving the bird defenseless against this $600-million-a-year disease. The solution: A specially developed chicken monoclonal antibody that blocks the parasite's ability to attach to and ultimately invade the defensive cells, called cytotoxic T-cells. Researchers also are investigating the use of cytokines--substances produced naturally by the chicken's white blood cells--as a weapon against coccidia. Laboratory tests show some cytokines inhibit development of coccidia parasites in the bird. They also turn precursor cytotoxic cells into active cytotoxic cells that hunt down and kill parasite-infected host cells. Cytokines rally white blood cells called macrophages to devour and destroy the parasites. Unfortunately, coccidia thwart pharmaceutical treatments by rapidly developing resistance to the drugs used against them.
Immunology and Disease Resistance Laboratory, Beltsville, MD
Hyun S. Lillehoj, (301) 504-8771

Neutrophils--a type of white blood cell--go into action against dairy cows' mastitis infections when they get the signal from a naturally produced protein. The protein was isolated and purified in studies in 1994-95 by scientists with ARS and the Institut National de la Recherches Agronomique, Nouzilly, France. The next step: Pinpointing how the protein directs neutrophils into the mammary gland and how much protein is needed for an effective neutrophil response. Mastitis, an infection of the cows' udder, costs U.S. dairy farmers $2 billion annually in treatment and lost milk production. When a cow's udder becomes infected, neutrophils rush to attack the invading bacteria. Until now, researchers had little information on what triggered the neutrophils' charge. The protein might someday be used in cows to protect against mastitis-causing bacteria.
Immunology and Disease Resistance Laboratory, Beltsville, MD
Max J. Paape, (301) 504-8302

Last Updated: January 28, 1997
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