Methods for selection and generation of genome edited T cells
Methods are described herein for isolating clonal populations of T cells having a defined genetic modification. The methods are performed, at least in part, in a microfluidic device comprising one or more sequestration pens. The methods include the steps of: maintaining individual T cells (or precursors thereof) that have undergone a genomic editing process in corresponding sequestration pens of a microfluidic device; expanding the T cells into respective clonal populations of T cells; detecting, in one or more T cells of each clonal population, the absence of a cell surface marker that was present in the individual T cells (or precursors thereof); and detecting, in one or more T cells of each clonal population, the presence of a first nucleic acid sequence that is indicative of the presence of an on-target genome edit in the clonal population of T cells. Also described are compositions comprising one or more clonal populations of T cells isolated according to the methods disclosed herein.
1. A method of generating a clonal population of genetically modified T cells in a microfluidic device comprising a sequestration pen, the method comprising:
maintaining a first T cell in the sequestration pen of the microfluidic device, wherein the first T cell has undergone a genome editing process;
expanding the first T cell into a clonal population of T cells;
detecting, in one or more T cells of the clonal population, the absence of a cell surface marker that was present in the first T cell or precursor thereof; and
detecting, in one or more T cells of the clonal population, the presence of a first nucleic acid sequence, wherein the first nucleic acid sequence indicates the presence of an on-target genome edit in the clonal population of T cells.
2. A method of generating a clonal population of genetically modified T cells in a microfluidic device comprising a sequestration pen, the method comprising:
maintaining a first T cell in the sequestration pen of the microfluidic device, wherein the first T cell has undergone a genome editing process;
expanding the first T cell into a clonal population of T cells; and
detecting, in one or more T cells of the clonal population, the presence of a first nucleic acid sequence, wherein the first nucleic acid sequence indicates the presence of an on-target genome edit in the clonal population of T cells.
3. The method of claim 1 , wherein the first T cell is a mammalian cell.
4. The method of claim 3 , wherein the first T cell is a human cell.
5. The method of claim 3 , wherein the first T cell expresses CD3 and at least one of CD4, CD8, T-bet, GATA-3, CD25, Foxp3, ROR-gammaT, CD38, and CD40.
6. The method of claim 1 further comprising:
contacting the first T cell with a genome editing biomolecule; and
introducing the first T cell into the microfluidic device.
7. The method of claim 6 , wherein the genome editing biomolecule comprises a donor template nucleic acid molecule or the method further comprises contacting the first T cell with a donor template nucleic acid molecule.
8. The method of claim 7 , wherein the donor template nucleic acid molecule comprises all or part of the first nucleic acid sequence.
9. The method of claim 6 , wherein contacting the first T cell with a genome editing biomolecule is performed prior to introducing the first T cell into the microfluidic device.
10. The method of claim 6 , wherein introducing the first T cell into the microfluidic device is performed prior to contacting the first T cell with a genome editing biomolecule.
11. The method of claim 6 , further comprising:
selecting the first T cell based on one or more characteristics selected from morphology, size, production of a protein of interest, the presence of one or more cell surface markers, and/or reaction with a specific antibody.
12. The method of claim 11 , further comprising:
positioning the first T cell in the sequestration pen, wherein said positioning is performed after selecting the first T cell.
13. The method of claim 1 , wherein the microfluidic device comprises a substrate having a DEP-configuration, and
wherein the method further comprises positioning the first T cell in the sequestration pen using dielectrophoretic (DEP) force.
14. The method of claim 1 , wherein detecting the presence of the first nucleic acid sequence comprises:
selecting one or more T cells from the clonal population of T cells; and
extracting nucleic acid from the one or more selected T cells.
15. The method of claim 14 , further comprising:
(i) moving the one or more selected T cells out of the sequestration pen; and
exporting the one or more selected T cells from the microfluidic device, wherein the nucleic acid is extracted from the one or more selected T cells outside of the microfluidic device;
(ii) moving the one or more selected T cells from the sequestration pen to a separate region within the microfluidic device, wherein the nucleic acid is extracted from the one or more selected T cells in the separate region; or
(iii) amplifying the extracted nucleic acid.
16. The method of claim 1 , wherein the on-target genome edit comprises a deletion of endogenous deoxyribonucleic acid (DNA) or an insertion of exogenous deoxyribonucleic acid (DNA) at a target site in the genome.
17. The method of claim 16 , wherein the insertion encodes a functional biomolecule, a barcode, and/or a reporter molecule.
18. The method of claim 1 , further comprising:
(i) detecting, in one or more T cells of the clonal population of T cells, the presence of a second nucleic acid sequence, wherein the combination of the first nucleic acid sequence and the second nucleic acid sequence indicates the presence of the on-target genome edit in the clonal population of T cells; or
(ii) detecting, in one or more cells of the clonal population of T cells, the presence of an additional nucleic acid sequence, wherein the additional nucleic acid sequence indicates the presence of an off-target genome edit in the clonal population of T cells, and wherein the off-target genome edit comprises a deletion of endogenous DNA and/or an insertion of exogenous DNA at a site in the genome other than the target site.
19. The method of claim 1 , wherein the microfluidic device comprises a first portion having a substrate that has a dielectrophoresis (DEP) configuration and a second portion that has a substrate that has an electrowetting (EW) configuration, and wherein the sequestration pen is located in the first portion of the microfluidic device.
20. The method of claim 1 , wherein expanding the first T cell into a clonal population of T cells further comprises:
monitoring one or more characteristics of the T cells of the clonal population for a period of time.
21. The method of claim 20 , wherein the monitoring comprises:
identifying changes in the size and/or morphology of the T cells of the clonal population;
determining the rate of proliferation of the first T cell into the clonal population of T cells; and/or
assessing the production of a protein of interest, the presence of one or more cell surface markers, and/or reaction with a specific antibody.
22. The method of claim 1 , further comprising:
exporting one or more cells of the clonal population of genetically modified T cells from the microfluidic device into a well plate, and
culturing the one or more T cells in the well plate.
23. A method of generating a clonal population of genetically modified T cells in a microfluidic device comprising a sequestration pen, the method comprising:
maintaining a first T cell in the sequestration pen of the microfluidic device, wherein the first T cell has undergone a genome editing process;
expanding the first T cell into a clonal population of T cells;
detecting, in one or more T cells of the clonal population, the absence of a cell surface marker that was present in the first T cell or precursor thereof; and
detecting, in one or more T cells of the clonal population, the presence of a first nucleic acid sequence, wherein the first nucleic acid sequence indicates the presence of an on-target genome edit in the clonal population of T cells,
wherein at least one inner surface of the sequestration pen, or a portion thereof, is a conditioned surface, wherein the conditioned surface comprises covalently-linked molecules, each having a linking group covalently bound to the at least one inner surface of the sequestration pen, or the portion thereof, and a moiety covalently bound to the linking group, wherein the moieties of the covalently-linked molecules provide a layer of organic and/or hydrophilic molecules suitable for maintenance and/or expansion of the genome-edited first cell.
24. The method of claim 1 , wherein the microfluidic device comprises a plurality of sequestration pens, and wherein the method is performed on a plurality of T cells to thereby generate a plurality of clonal populations of genetically modified T cells, optionally wherein one or more steps of the method are performed on the plurality of T cells in parallel.
25. A composition comprising a clonal population of genetically modified T cells, wherein the clonal population was generated by the method of claim 1 .
26. The method of claim 1 , wherein the one or more T cells of the clonal population on which detecting the presence of a first nucleic acid sequence is performed is a first subset of the clonal population of T cells, and wherein a second subset of the clonal population of T cells is preserved.