Thomas Jefferson University

Valigen (us), Inc.

Kimeragen, Inc.

Allyson D Cole-Strauss

Eric B Kmiec

Howard Gamper

Howard B Gamper, Jr

Kyonggeun Yoon

The invention is based on the reaction of recombinagenic oligonucleotides in a cell-free system containing a cytoplasmic cell extract and a test duplex DNA on a plasmid. The reaction specifically converts a mutant kan gene to recover the resistant phenotype in transformed MutS, RecA deficient bacteria and allows for the rapid and quantitative comparison of recombinagenic oligonucleobases. Using this system a type of Duplex Mutational Vector termed a Heteroduplex Mutational Vector, was shown to be more active in than the types of mutational vectors heretofore tested. Further improvements in activity were obtained by replacement of a tetrathymidine linker by a nuclease resistant oligonucleotide, such as tetra-2&prime;-O-methyl-uridine, to link the two strands of the Duplex Mutational Vector and removal of the DNA-containing intervening segment. The claims concern Duplex Mutational Vectors that contain the above improvements. In an alternative embodiment the claims concern a reaction mixture containing a recombinagenic oligonucleobase, a cell-free enzyme mixture and a duplex DNA containing a target sequence. In yet an alternative embodiment, the invention concerns the use of such mixture to test improvements in recombinagenic oligonucleobases, as well as to test the effects of compounds on the activity of the cell-free enzyme mixture and also to make specific changes in the target DNA sequence.

Eukaryotic use of improved chimeric mutational vectors

The invention is based on the reaction of Duplex Mutational Vector in a cell-free system containing a cytoplasmic cell extract and a test plasmid. The reaction specifically converts a mutant kan.sup.r gene to recover the resistant phenotype in transformed MutS, RecA deficient bacteria. Using this system a type of Duplex Mutational Vector termed a Non-Chimeric Mutational Vector, having no RNA:DNA hybrid-duplex is shown to be an effective substrate for eukaryotic enzymes. The invention concerns the use of Non-Chimeric Mutational Vectors protected from 3' exonuclease attack in eukaryotic cells. Such protection can be conferred by replacement of a tetrathymidine linker by a nuclease resistant oligonucleotide, such as tetra-2'-O-methyl-uridine, to link the two strands of the recombinagenic oligonucleobase.

Eukaryotic use of non-chimeric mutational vectors

The invention concerns methods of introducing specific alterations in the genome of cells that have been removed from a subject suffering from a medical condition that is the result of a genetic lesion. The specific alteration is designed to correct the genetic lesion. The method comprises introducing an oligonucleotide compound, containing ribonucleotides and deoxyribonucleotides, into the cells and thereafter reintroducing the cells into the subject. Specific types of cells include hematopoietic stem cells and hepatocytes. The ribonucleotides of the compound can have 2-substituents that enhance their resistance to RNase.

Method and oligonucleobase compounds for curing diseases caused by

The invention concerns the use of duplex oligonucleotides having both 2'-deoxyribonucleotides and ribonucleotides, wherein there is base pairing between the two types of nucleotides. The sequence of the oligonucleotide is selected so that the 3' and 5' most regions of the oligonucleotide are homologous with (identical to) the sequence of a preselected target gene of a cell. The two regions of homology embrace a region that is heterologous with the target sequence. The introduction of the oligonucleotide into the nucleus of the cell causes the alteration of the target gene such that the sequence of the altered target gene is the sequence of the heterologous region. Consequently, the oligonucleotides of the invention are termed Chimeric Repair Vectors (CRV). In one embodiment of the invention the target gene is a globin gene and the target cell is a hematopoietic stem cell. This embodiment can be used to correct certain hemoglobinopathies such as Sickle Cell Disease, .beta.-thalassemia, and also Gaucher Disease. The rate of correction of the globin gene is high enough so that no selection of the treated hematopoietic stem cells is required to obtain a therapeutically significant effect. In one embodiment the ribose moieties of the nucleotides of the CRV contain methylated 2'-oxygens.

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Narberth, PA, United States of America

Allyson D Cole-Strauss