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Background
UCSD researchers have discovered that a non-human sialic acid molecule from red meat and milk is incorporated in human cells through dietary intake, and builds up in tumors. The compound, called Neu5Gc, is found on the surfaces of animal cells but is not found in humans, and may be one reason why animal-to-human organ and tissue transplants do not work well. Humans carry Neu5Ac instead of Neu5Gc.
The UCSD researchers developed an antibody to Neu5Gc, and used it to determine that Neu5Gc appears in human tumor samples, but is much less abundant in healthy tissue. The small amounts of Neu5Gc in normal tissues also raise the possibility that anti-Neu5Gc antibodies are involved in autoimmunity. Autoimmune disease occur when the body mistakenly attacks healthy tissue and include type-1 or juvenile diabetes and some types of arthritis. Additional tests showed that most people had made their own antibodies that recognized Neu5Gc, and thus could potentially initiate an inflammatory immune response.
Inventions
Methods for detecting Neu5Gc
Neu5Gc is not expressed by human genes, but appears to be incorporated into human tissues from dietary sources such as red meat. The researchers have developed methods to monitor dietary sources and total body load of the non-human, and potentially toxic sugar Neu5Gc or its precursor ManNGc. Monitoring Neu5Gc has applications in disease detection, and correlation of dietary intake of foods containing Neu5Gc with disease progression.
Method for detecting serum antibodies against NeuGc
Anti-Neu5Gc antibodies have been correlated with certain diseases such as hepatitis and rheumatoid arthritis, and in xenograft rejection. UCSD researchers have developed assays compatible with standard microtiter plates to detect human serum antibodies against Neu5Gc with high specificity and high sensitivity. The invention has potential applications in diagnosing human diseases associated with Neu5Gc incorporation, such as carcinoma and atherosclerosis, and in monitoring the immune response to this antigenic sugar from dietary intake.
Anti-Neu5Gc Antibody
Historically, sialic-acid specific antibodies have been difficult to purify. Most anti-carbohydrate antibodies are low in affinity, requiring a high density of antigen to bind. UCSD researchers have developed high affinity monoclonal antibodies to Neu5Gc using a proprietary method based on selection and purification of rare antibodies (see also case#2003-123).
Reference: Proc Natl Acad Sci U S A. 2003 Oct 14;100(21):12045-50.
IP STATUS: Patent application filed.
Case Number: SD2003-142, SD2003-141
Inquiries To:
invent@ucsd.edu
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