US 12,252,713 B2
Cell hybrids as virus packaging cells for high efficiency production of gene therapy vectors and viral vaccines
Lawrence Forman, San Mateo, CA (US); and Kathy Ngo, San Francisco, CA (US)
Assigned to Cho Plus, Inc., South San Francisco, CA (US)
Filed by CHO Plus, Inc., South San Francisco, CA (US)
Filed on Sep. 14, 2023, as Appl. No. 18/368,338.
Application 18/368,338 is a division of application No. 18/332,612, filed on Jun. 9, 2023.
Application 18/368,338 is a division of application No. PCT/US2023/024973, filed on Jun. 9, 2023.
Claims priority of provisional application 63/350,863, filed on Jun. 9, 2022.
Prior Publication US 2024/0043810 A1, Feb. 8, 2024
This patent is subject to a terminal disclaimer.
Int. Cl. C12N 5/071 (2010.01); C12N 15/86 (2006.01)
CPC C12N 5/0686 (2013.01) [C12N 15/86 (2013.01); C12N 2511/00 (2013.01); C12N 2750/14143 (2013.01); C12N 2750/14152 (2013.01)] 20 Claims
 
1. A process for establishing a packaging cell line for high efficiency production of viral vectors or particles, the process comprising:
(a) providing a starter population of cultured cells that are able to package a species of viral vector or particle when genetically altered to express genes that encode the viral vector or particle;
(b) forming hybrid cells from the starter population, each comprising two or more cells;
(c) dividing the hybrid cells into a plurality of aliquots;
(d) taking a sample of cells from each of the aliquots;
(e) genetically altering cells in each of the samples to express genes that encode a test viral vector or particle of said species;
(f) measuring production of the test viral vector or particle by cells in each of the samples, thereby identifying which aliquots contain cells that produce a higher functional titer of the test viral vector or particle, compared with cells in other aliquots;
(g) expanding in culture cells from one or more of the aliquots identified in step (f), thereby establishing a packaging cell line which when genetically altered to express said species of viral vector or particle, produces more viral vector or particle per liter of culture fluid, compared with the starter population.