Blood cells having modified antigenicity

a technology of blood cells and antigens, applied in the field of blood cells having modified antigens, can solve the problems of only converting the more abundant a cells, the lack of blood type o donors, and the development and utilization of enzyme conversion universal o cells
US20050208655A1Inactive Publication Date: 2005-09-22ZYMEQUEST
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Patent Information

Authority / Receiving Office
US · United States
Patent Type
Applications(United States)
Current Assignee / Owner
ZYMEQUEST
Publication Date
2005-09-22
Estimated Expiration
Not applicable · inactive patent

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Abstract

This invention relates to enzymatic removal of type A and B antigens from blood group A, B, and AB reactive cells in blood products, and thereby converting these to non-A and non-B reactive cells. The invention further relates to using unique alpha N-acetylgalactosaminidases and alpha-galactosidases with superior kinetic properties for removing the immunodominant monosaccharides of the blood group A and B antigens and improved performance in enzymatic conversion of red blood cells. The preferred unique alpha-N-acetylgalactosaminidases and alpha-galactosidases exhibit the following characteristics: (i) exclusive, preferred or no less than 10% substrate specificity for the type A and B branched polysaccharide structures relative to measurable activity with simple mono- and disaccharide structures and aglycon derivatives hereof; (ii) optimal performance at neutral pH with blood group oligosaccharides and in enzymatic conversion of cells; and (iii) a favorable kinetic constant Km with mono- and oligosaccharide substrates. The conversion methods of the invention use significantly lower amounts of recombinant glycosidase enzymes than previous and result in complete sero-conversion of all blood group A and B red cells.
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Description

RELATED APPLICATIONS

[0001] This application is a continuation of and claims priority to U.S. Ser. No. 10 / 251,271 filed Sep. 20, 2002, which in turn claims priority to U.S. Provisional Application No. 60 / 324,970, filed on Sep. 25, 2001, and No. 60 / 361,769, filed on Mar. 5, 2002; the entire contents of each application is hereby incorporated herein by reference.FIELD OF THE INVENTION

[0002] This invention relates to enzymatic removal of type A and B antigens from blood group A, B, and AB reactive cells in blood products, and thereby converting these to non-A and non-B reactive cells. Specifically this invention relates to enzymatic removal of the immunodominant monosaccharides specifying the blood group A and B antigens, namely alpha 1,3-D-galactose and alpha 1,3-D-N-acetylgalactosamine, respectively. More particularly, this invention relates to the use of unique alpha-N-acetylgalactosaminidases and alpha-galactosidases with superior kinetic properties for removal of the immunodomina...

Claims

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