Precise microbiota engineering at the cellular level
Stably immunized cells and methods of making stably immunized cells are provided. Methods of altering the microbiota of an ecological environment are provided. Methods of modifying target chromosomes are provided. Methods of delivering genetic material to target cells are provided.
1. A method of altering a resident gut bacterial cell population in an individual's gut, comprising the steps of:
depleting one or more target resident gut bacterial cells from the individual's gut by adding a dose of a bacteriophage to the individual's gut;
releasing into the individual's gut a dose of an engineered bacterial cells having immunity against the bacteriophage; and
allowing the engineered bacterial cells to colonize the individual's gut in place of the depleted target resident gut bacterial cells,
wherein the engineered bacterial cell expresses a Cas enzyme and comprises a first foreign nucleic acid sequence encoding a plurality of RNA sequences having spacer sequences complementary to conserved nucleic acid sequences of the bacteriophage, wherein the engineered bacterial cell expresses the foreign nucleic acid sequence encoding the plurality of RNA sequences, and wherein the Cas enzyme interacts with one or more of the plurality of RNA sequences and cleaves a conserved nucleic acid sequence of the bacteriophage.
2. The method of claim 1 , wherein the engineered bacterial cell has Cas9-mediated resistance.
3. The method of claim 1 , wherein the Cas enzyme is Cas9.
4. The method of claim 1 , wherein the engineered bacterial cell has further comprises a second foreign nucleic acid encoding the Cas enzyme.
5. The method of claim 1 , wherein the Cas enzyme is an orthogonal Cas9.
6. The method of claim 1 , wherein at least five of the plurality of RNA sequences bind to consensus nucleic acid sequences of the bacteriophage.
7. The method of claim 1 , wherein at least five of the plurality of RNA sequences bind to complementary exogenous virulence nucleic acid sequences.
8. The method of claim 1 , wherein one or more of the plurality of RNA sequences is complementary to an exogenous nucleic acid sequence encoding a product that is toxic to the target resident gut bacterial cells or to a host of the target resident gut bacterial cells.
9. The method of claim 1 , wherein the foreign nucleic acid sequence is provided as a mobile genetic element.
10. The method of claim 1 , wherein the foreign nucleic acid sequence is introduced into the engineered bacterial cell by a method selected from the group consisting of bacterial conjugation, infection, transfection and transformation.
11. The method of claim 1 , wherein the engineered bacterial cell is non-pathogenic to a host.
12. The method of claim 10 , further comprising the step of integrating the foreign nucleic acid sequence into the genome of the engineered bacterial cell using homologous recombination.
13. The method of claim 12 , wherein two or more foreign nucleic acid sequences are integrated into the genome of the engineered bacterial cell using homologous recombination.
14. The method of claim 1 , wherein the plurality of RNA sequences is selected from the group consisting of pre-crRNA, crRNA, guide RNA, and any combinations thereof.
15. The method of claim 1 , wherein the bacteriophage is a T4 or T7 bacteriophage.