Somatic human cell line mutations
The invention provides for a method of producing a mutant somatic human cell line of cells comprising a genomic mutation of interest (MOI) at a predefined genomic site of interest (GOI) in close proximity to a genomic target site, which comprises: a) providing a guide RNA (gRNA) comprising a tracrRNA in conjunction with crRNA including an oligonucleotide sequence that hybridizes with the target site; b) providing an RNA-guided endonuclease which catalyzes the DNA break at the target site upon hybridizing with the gRNA; c) introducing the gRNA into the cells in the presence of the endonuclease to obtain a repertoire of cells comprising a variety of genomic mutations at the target site; d) selecting a cell from said repertoire which comprises a MOI; wherein the cell is haploid for the genomic locus of the target site; and e) expanding the cell to obtain the mutant cell line. The invention further provides for a mutant human somatic cell line obtainable by such method; and libraries of mutant human somatic cell lines of isogenic cells with a variety of genomic mutations at different predefined genomic target sites.
1. A method of producing a mutant somatic human cell line of cells comprising a genomic mutation of interest (MOI) at a predefined genomic site of interest (GOI) in close proximity to a genomic target site, the method comprising:
a) providing a guide RNA (gRNA) comprising a tracrRNA in conjunction with crRNA including an oligonucleotide sequence that hybridizes with the target site;
b) providing an RNA-guided endonuclease which catalyzes a DNA break at the target site upon hybridizing with the gRNA;
c) introducing the gRNA into near-haploid or fully haploid cells in the presence of the endonuclease to obtain a repertoire of cells comprising a variety of genomic mutations at the target site;
d) selecting a cell from said repertoire which comprises the MOI, wherein the selected cell is a near-haploid or fully haploid cell; and
e) expanding the selected near-haploid or fully haploid cell to obtain the mutant cell line;
wherein the selected near-haploid or fully haploid cell, the mutant cell line, or both, are adherent.
2. The method of claim 1 , wherein the MOI is at least one of
(i) a mutation knocking out a function of a gene;
(ii) a mutation introducing at least one of a deletion, substitution, or insertion of one or more nucleotides; or
(iii) a mutation introducing an exchange sequence of a homology template.
3. The method of claim 1 , wherein
in step c), an expression plasmid incorporating a nucleic acid sequence to express the gRNA is used to transform the cells and to obtain a repertoire of transformant cells comprising the variety of genomic mutations at the target site; and
in step d), the selected near haploid or fully haploid cell is a transformant cell.
4. The method of claim 1 , wherein the selected cell is a fully haploid cell.
5. The method of claim 1 , wherein the gRNA comprises a sequence selected from the group consisting of SEQ ID 3, SEQ ID 13, SEQ ID 19, and any of SEQ ID 24-47.
6. The method of claim 1 , wherein the endonuclease is selected from the group consisting of CAS9 enzymes originating from any of Streptococcus pyogenes, Streptococcus thermophiles, Neisseria Meningitis or Treponema Denticola , or Cas9 nickases or artificial enzymes.
7. The method of claim 1 , wherein
A:
the gRNA comprises a nucleotide sequence chosen from SEQ ID 3, SEQ ID 25, or SEQ ID 26; and
the endonuclease comprises an amino acid sequence chosen from SEQ ID 1, SEQ ID 5, SEQ ID 7, SEQ ID 8, or SEQ ID 9; or
B:
the gRNA comprises a nucleotide sequence chosen from SEQ ID 13, one of SEQ IDs 27-40; and
the endonuclease comprises an amino acid sequence chosen from SEQ ID 10 or SEQ ID 15; or
C:
the gRNA comprises a nucleotide sequence chosen from SEQ ID 19, one of SEQ IDs 41-47; and
the endonuclease comprises an amino acid sequence chosen from SEQ ID 16 or SEQ ID 21.
8. The method of claim 1 , wherein the near-haploid or fully haploid cells of step c) are engineered to express at least one of a Cas9 endonuclease or the gRNA.
9. The method of claim 1 , wherein the DNA break is a double strand break or a paired single strand break proximal to a protospacer associated motif (PAM), and the genomic mutation is obtained by homology-directed repair or by non-homologous end-joining.
10. The method of claim 1 , wherein the MOI is obtained by cellular repair mechanisms induced by the DNA break.
11. The method of claim 1 , wherein the MO1 comprises a mutation introducing an exchange sequence of a homology template, and the homology template is
a) an oligonucleotide of 20-200 bp length;
b) a PCR product of 20-5000 bp length; or
c) any of a) or b) comprised in a donor plasmid.
12. The method of claim 11 , wherein the exchange sequence is embedded into a recombining sequence, overlapping with a recombining sequence, or flanked by one or more recombining sequences.
13. The method of claim 11 , wherein the exchange sequence has a sequence homology of at least 95% to the GOI.
14. The method of claim 11 , wherein the homology template comprises a photospacer associated motif (PAM).
15. The method of claim 1 , further comprising cultivating the mutant cell line by asexually replicating the chromosomes within the cells of the mutant cell line, thereby obtaining a population of individual cells, and upon determination of a karyotype of individual cells, selecting a diploid cell, and further expanding the diploid cell to obtain a mutant cell line comprising a diploid karyotype.
16. The method of claim 1 , wherein a library of mutant human somatic cell lines of isogenic cells with a variety of genomic mutations at different predefined genomic target sites is produced.
17. The method of claim 4 , wherein the selected fully haploid cell is of the HAP2 cell line deposited under DSM ACC3220.
18. The method of claim 9 , wherein the DNA break is 3 bp upstream of the PAM.
19. The method of claim 10 , wherein the cellular repair mechanisms include introducing at least one of a frameshift mutation, insertion, substitution, or deletion of one or more nucleotides, or a combination thereof.
20. The method of claim 12 , wherein the exchange sequence is flanked by recombining sequences at the 5′-end and the 3′-end of the exchange sequence, the recombining sequence being capable of homologous recombination with the GOI.
21. The method of claim 13 wherein the exchange sequence comprises one or more point mutations, or a modified DNA region causing at least one of a different DNA expression or a different phenotype.
22. The method of claim 14 , wherein the PAM is mutated to prevent cleavage and repair of the DNA break by non-homologous end joining.
23. A method of producing a mutant somatic human cell line of cells comprising a genomic mutation of interest (MOI) at a predefined genomic site of interest (GOI) in close proximity to a genomic target site, the method comprising:
providing a guide RNA (gRNA) comprising a sequence selected from the group consisting of SEQ ID 3, SEQ ID 13, SEQ ID 19, SEQ ID 24-47, or a homolog of an aforementioned gRNA sequence having at least 90% degree of homology, that hybridizes with the target site;
providing an RNA-guided endonuclease which catalyzes a DNA break at the target site upon hybridizing with the gRNA comprising a sequence selected from the group consisting of SEQ ID 1, SEQ ID 5, SEQ ID 7-10, SEQ ID 15, SEQ ID 16, SEQ ID 21, or a homolog of an aforementioned endonuclease sequence having at least 90% degree of homology;
introducing the gRNA into fully haploid cells in the presence of the endonuclease to obtain a repertoire of cells comprising a variety of genomic mutations at the target site;
selecting a cell from said repertoire which comprises the MOI, wherein the selected cell is a fully haploid cell; and
expanding the selected fully haploid cell to obtain the mutant cell line.