Patent
The present invention provides Listeria that are attenuated for entry into non-phagocytic cells as well as a variety of methods of inducing immune responses involving administering compositions comprising the attenuated Listeria . Some of the attenuated Listeria are mutant Listeria that comprise at least one mutation in a gene encoding an invasin, such as an internalin. Some of the attenuated Listeria are further attenuated for cell-to-cell spread. Pharmaceutical compositions and vaccines useful in the methods of the invention are further provided. Methods of making and improving vaccines are also provided.
1. An attenuated Listeria monocytogenes bacterium, wherein the attenuated bacterium comprises:
one or more genetic mutations in the actA gene and the inlB genes which attenuates the ability of the Listeria to spread relative to wild type Listeria monocytogenes and which attenuates the ability of the Listeria to invade at least some cells relative to wild type Listeria monocytogenes ; and
a functional genomic inlA gene, whereby the attenuated bacterium expresses InlA protein.
2. An attenuated Listeria monocytogenes bacterium according to claim 1 , wherein the mutation(s) in the actA gene and the inlB genes comprise a deletion of all or a portion of the coding region of the actA gene and the inlB genes.
3. An attenuated Listeria monocytogenes bacterium according to claim 1 , further comprising: (i) interstrand crosslinks introduced between the strands of genomic DNA double helix, said interstrand crosslinks inhibiting replication of said attenuated bacterium, and (ii) one or more genetic mutations in uvrA and uvrB genes inhibiting excision repair of said interstrand crosslinks.
4. An attenuated Listeria monocytogenes bacterium according to claim 1 , further comprising a nucleic acid sequence encoding a polypeptide heterologous to said attenuated bacterium operably linked to a promoter sequence directing expression of the heterologous polypeptide by the attenuated bacterium.
5. An attenuated Listeria monocytogenes bacterium according to claim 3 , wherein the interstrand crosslinks are introduced by reaction with a psoralen activated by irradiation or by reaction with an alkylating agent.
6. An attenuated Listeria monocytogenes bacterium according to claim 5 , wherein the interstrand crosslinks are introduced by reaction with 4′-(4-amino-2-oxa)butyl-4,5′,8-trimethylpsoralen activated by irradiation.
7. An attenuated Listeria monocytogenes bacterium according to claim 4 , wherein the polypeptide heterologous to said attenuated bacterium is a tumor antigen.
8. An attenuated Listeria monocytogenes bacterium according to claim 7 , wherein the tumor antigen is mesothelin, SPAS-1, proteinase-3, SP-17, gp100, PAGE-4, TARP, Her-2/neu, WT-1, NY-ESO-1, PSMA, K-ras, survivin, mcm-2, or CEA, or an antigen derived from mesothelin, SPAS-1, proteinase-3, SP-17, gp100, PAGE-4, TARP, Her-2/neu, WT-1, NY-ESO-1, PSMA, K-ras or CEA.
9. An attenuated Listeria bacterium according to claim 4 , wherein the polypeptide heterologous to said attenuated bacterium is an infectious disease antigen.
10. An attenuated Listeria bacterium according to claim 9 , wherein the antigen is derived from a Human Immunodeficiency Virus or a hepatitis virus.