Engineering selection stringency on expression vector for the production of recombinant human alpha1-antitrypsin using Chinese Hamster Ovary cells

Table 1 Growth and productivity of top cell pools.

MTX concentration	Vector	Pool 1				Pool 2				Average
		Max titer¹ (mg/l)	q_p (pcd)	t_D (h)	Fold titer increase ²	Max titer¹ (mg/l)	q_p (pcd)	t_D (h)	Fold titer increase ²	Max titer¹ (mg/l)	q_p (pcd)	t_D (h)
50 nM	pAID	256	17.6	46	5.6					256	17.6	46
	pAIDp	492	25.7	36	4.2	244	10.9	36	3.1	368	18.3	36
	pAIDpp	647	29.0	33	4.4	539	25.9	44	5.4	593	27.5	39
	pAI772Dp	1054	41.3	28	8.5	937	33.8	26	8.2	996	37.6	27
	pAID*	275	14.4	41	3.1	170	7.8	40	2.2	222	11.1	40
	pAID*p	277	8.4	33	2.0					277	8.4	33
300 nM	pAID	560	32.5	34	2.2					560	32.5	34
	pAIDp	514	25.8	33	1.0	240	13.1	37	1.0	377	19.5	35
	pAIDpp	1146	88.2	45	1.8	846	41.9	41	1.6	996	65.0	43
	pAI772Dp	1111	48.6	42	1.1	863	35.4	27	0.9	987	42.0	34
	pAID*	721	34.3	43	2.6	398	22.1	33	2.3	559	28.2	38
	pAID*p	412	17.7	29	1.5					412	17.7	29

¹ Maximum titer was taken as the highest rhA1AT titer assayed from the first 11 days of the batch culture.
² Fold titer increase for cell pools in 50 nM MTX suspension culture was compared against the titers of the same cell pools in adherent 96 well plate cultures, whereas that for cell pools in 300 nM MTX suspension culture was compared against the titers of the same cell pools in 50 nM MTX suspension culture.

ISSN: 1753-6561