Semi-static cell culture
The present invention relates to cell culture in bioreactors, such as flexible cellbag bioreactors. More specifically the present invention relates to methods for simplifying the production of clinically relevant cell products for use in cell therapy.
1. A method comprising:
(i) inoculating cells in a suspension into a non-static bioreactor;
(ii) adding an antigen stimulus to said cells in said suspension in said non-static bioreactor kept at a first rocking rate no greater than 4 rpm and at an angle of no greater than 4 degrees;
(iii) adding at least a cell growth co-factor to said non-static bioreactor;
(iv) expanding said cells to result in a clinically relevant cell product in said non-static bioreactor kept at a second rocking rate which is higher than said first rocking rate and at an angle of greater than 4 degrees, wherein the second rocking rate is (a) between 4-8 rpm and an angle of 4-6 degrees for cell densities of <2 6 cells/ml and with volume less than 1 L, and (b) between 8-10 rpm and an angle of 6-15 degrees for >2 6 cells/ml and volume greater than 1 L;
wherein said cells are leucocytes.
2. The method of claim 1 wherein steps (ii) and (iii) are repeated one or more times during step (iv).
3. The method of claim 1 wherein said leucocytes are selected from the group comprising lymphocytes, monocytes or cells derived from monocytes.
4. The method of claim 1 wherein said leucocytes are peripheral blood mononuclear cells (PBMCs).
5. The method of claim 1 wherein said non-static bioreactor comprises a flexible cell bag.
6. The method of claim 1 wherein said antigen stimulus comprises antigenic peptides or tumour lysate.
7. The method of claim 1 wherein said step of expanding said cells comprises replacing a culture medium in the suspension at regular intervals.
8. The method of claim 1 wherein said cell growth co-factor comprises anti-CD28 and/or anti-CD3 monoclonal antibodies.
9. The method of claim 8 wherein said cell growth co-factor is added prior to the expanding step (iv).
10. The method of claim 8 wherein said cell growth co-factor is a cytokine or a cocktail of cytokines.
11. The method of claim 10 wherein said cytokine is selected from interleukin-2 (IL-2), interleukin-4 (IL-4), interleukin-7 (IL-7), interleukin-12 (IL-12), interleukin-15 (IL-15) and interleukin-21 (IL-21).
12. The method of claim 10 wherein said cell growth co-factor is added prior to the expanding step (iv).
13. The method of claim 10 wherein said cell growth co-factor is added at regular intervals during said expanding step (iv).
14. The method of claim 1 wherein said clinically relevant cell product comprises antigen-specific T cells, regulatory T cells or genetically-modified PBMCs.
15. The method of claim 14 wherein said clinically relevant cell product comprises antigen-specific T cells or genetically-modified PBMCs.
16. The method of claim 14 wherein said antigen-specific T cells are cytotoxic virus-specific T cells or tumour-specific T-cells.
17. The method of claim 14 wherein said genetically-modified PBMCs comprise chimeric antigen receptor (CAR) T cells or TCR-modified T cells.
18. The method of claim 1 wherein said first rocking rate is between 2-4 rpm and at an angle between 2-4 degrees.
19. The method of claim 1 wherein the non-static bioreactor comprises means to control evaporation and/or condensation and/or accumulation of waste metabolites.
20. The method of claim 19 wherein said means to control comprises thermal insulation.
21. The method of claim 19 wherein said means to control comprises controlling a gas flow rate of gas supplied to the non-static bioreactor.
22. The method of claim 19 wherein said means to control comprises daily medium additions.
23. The method of claim 1 , wherein the wherein the second rocking rate is between 8-10 rpm and an angle of 6 degrees for >2 6 cells/ml and volume greater than 1 L.