Innovir Laboratories, Inc.

Yale University

Allan R Goldberg

Shaji T George

Michael Ma

Garry B Takle

Martina Werner

Umberto Pace

Disclosed are a method and compositions for delivering nucleic acids to bacterial cells. The method does not require manipulation of the bacteria and is therefore particularly suited to delivery of nucleic acids to bacteria in natural environments, including inside animals bodies. The method generally involves conjugating the nucleic acid to be delivered with a cationic porphyrin and bringing the conjugate and the target bacterial cells into contact. Both the porphyrin and conjugated nucleic acid are taken up by the bacterial cells and the nucleic acid can then have a biological effect on the cells. Specifically disclosed is a method for converting drug-resistant bacterial cells to drug-sensitive cells by delivery of external guide sequences to the cells which then promote cleavage of RNA molecules involved in conferring the drug-resistant phenotype on the cells. The drug-resistant phenotype of the cells is thus converted to a drug-sensitive phenotype. The drug-sensitive cells are then susceptible to drug therapy. Also disclosed is a method and compositions for killing eukaryotic pathogens or converting drug-resistant eukaryotic cells to drug-sensitive cells. The method involves the delivery of external guide sequences, ribozymes, or vectors encoding external guide sequences or ribozymes, to eukaryotic cells. Preferred target eukaryotic cells for the disclosed method include algae, protozoa, fungi, slime mold, and cells of helminths.

Phenotypic conversion of cells mediated by external guide sequences

Modified external guide sequence (EGS) molecules that mediate cleavage of specific target RNAs have been constructed. The modified molecules are external guide sequence molecules for RNAse P which are designed to specifically bind to and promote RNAse P-mediated cleavage of target RNA molecules and to have enhanced nuclease resistance. Specific regions are modified to achieve enhanced stability while maintaining RNAse P activity. Modified external guide sequence molecules suitable for use in the treatment of hepatitis B viral infections have been constructed.

Stabilized external guide sequences

Hepatitis delta is used as a vector for inhibition of viral infection and to express proteins in vivo in a cell-specific manner. The scope of delta's use as a vector is broadened in the present invention in several important ways. For example, a delta RNA genome capable of self-replication is enlarged to carry additional information, either coding for messenger RNA for a protein, or for a targeted ribozyme, which can be delivered to liver cells using delta's normally infectious properties, or to other cell types using chimeric delta viral agents carrying altered surface proteins. In another embodiment, the delta vector is made self-limiting, so that its role in delivering targeted information is separated from its viral property of unlimited infectious replication. Targeting is achieved through the use of sequences flanking the delta sequences that have affinity for sites on RNA to be cleaved.

Ribozyme compositions and expression vectors

Hepatitis delta virus compositions and expression vectors

EGS-mediated inactivation of target RNA

Ribozymes, sequences cleaving RNA, derived from sequences present in the hepatitis delta virus, have been engineered for greater specificity without increasing size. The specific ribozyme sequences are useful as reagents for cleaving RNA for experimental studies as well as antiviral therapies. Examples demonstrating the targeting of these sequences against HIV and Crohn's disease are described in detail. The sequences are also useful as diagnostics for the detection of hepatitis delta virus in tissue and fluid samples, as in blood banking, as well as in isolation and characterization of new viroids having ribozyme activity, using an RNA-specific hybridization method. Based on analysis of the two domain structure of the hepatitis delta virus, it is possible to construct a vector for expression of non-hepatitis delta virus proteins in mammalian cells.

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New York, NY, United States of America

Allan R Goldberg