Chemistry: molecular biology and microbiology – Micro-organism – tissue cell culture or enzyme using process... – Recombinant dna technique included in method of making a...
Patent
1995-05-26
1997-11-04
Chan, Christina Y.
Chemistry: molecular biology and microbiology
Micro-organism, tissue cell culture or enzyme using process...
Recombinant dna technique included in method of making a...
435328, 435346, 435 702, 5303873, 935103, 935109, 935 34, C07K 1644, C12P 2108, C12N 1506, C12N 1513
Patent
active
056838913
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/JP93/01723, filed Nov. 25, 1993.
TECHNICAL FIELD
The present invention relates to a method for producing an exogenous protein which comprises expressing efficiently an exogenous gene prepared by a genetic recombination, etc. and collecting the expressed protein. Specifically, it relates to an excellent method for producing an exogenous protein wherein the desired exogenous protein, especially a recombinant antibody, is produced by serum-free culture utilizing as a host cell for expression, a fused cell obtained by fusing a mouse myeloma with a lymphatic cell.
BACKGROUND ART
It has been expected to utilize monoclonal antibodies in industry with progress of cell fusion technique in recent years. However, in case of heterogenous antibodies other than a mouse-type antibody, when a heterogenous cell is fused with a myeloma cell line of rodents such as mouse, rat, etc., a phenomenon that a chromosome of said heterogenous antibody disappeared rapidly in a hybrid cell (hybridoma) is observed, and hence, it has been quite difficult to obtain a stable antibody-producing cell. Although cell fusion has also been attempted by using a homogenous myeloma cell line or B cell line other than those derived from rodents, no satisfactory results have been obtained.
On the other hand, with the progress of a genetic recombination technique, cloning of a gene has become easier. As for an antibody, analytical research has been developed at a genetic level, and as a result, it has become possible to isolate and express an antibody gene in a suitable host cell without deletion at a chromosomal level. However, an antibody production level by expression after introduction of an antibody gene was generally smaller than that of a hybrid cell prepared by a cell fusion technique, and hence, this expression method has not been practical. In order to solve this problem, a gene amplification system etc. with a DHFR gene etc. has been used, but in case of a mouse-derived cell system, it is generally said that an exogenous gene is not incorporated into a host chromosome as DM (Double Minutes) and thus instable. There are several reports on a DHFR gene amplification system using a mouse cell but they do not refer to a stability thereof.
A technique for antibody production by the genetic recombination has not been satisfactory in view of an expression system practically usable at an industrial level. Thus, it is desired to develop an excellent method for producing a recombinant antibody both in view of the expression and purification of a recombinant antibody gene.
SUMMARY
Under the circumstances, from the point of a method for producing a recombinant antibody using a serum-free culture, the present inventors have earnestly studied, and as a result, have found that the desired recombinant antibody is quite efficiently prepared by using, as a host cell, a fused cell which is prepared from a mouse myeloma and a lymphatic cell and which can be cultured in a serum-free medium (although such a cell may also be called as a hybrid cell, in the present invention, the characteristic hybrid cell used as a host cell for expression of an exogenous protein is referred to as a fused cell) and expressing an antibody gene in said fused cell, and in this way the present invention has been completed.
There have been reported several methods for producing an antibody by a genetic recombination using a mouse myeloma cell. In the hitherto known methods, however, a parent cell line (myeloma) itself is used as a host cell instead of being used for preparing a hybridoma, an exogenous gene is incorporated into said host cell and the antibody is expressed. However, when a mouse myeloma itself is used as a host cell for expression of an exogenous gene, it is difficult to prepare a cell suitable for culture in a serum-free medium and it deemed to be quite difficult to prepare a host cell which is both capable of growing in a serum-free medium like in a medium supplemented with serum and shows a stable gene expression efficiency.
A
REFERENCES:
patent: 4757018 (1988-07-01), Brown
patent: 5110737 (1992-05-01), Myoken et al.
patent: 5491088 (1996-02-01), Hellstrom et al.
Kovar, J and Franek, F. Immunology Letters. 7(6): 339-345, 1984.
Iwamoto, K et al. Cytotechnology, 6: 93-103, 1991.
Laskov, R et al. International Journal of Cancer. 48: 574-582. 1991.
Li, Jiliang et al, "Cholesterol requirement for growth of rodent parental eloma cells in serum free medium", Journal of Medical Colleges of PLA, 6(2), 135-40, 1991.
Sawada S et al, "Immunoprotective human monoclonal antibodies against five major serotypes of pseudomonas aeruginosa", The Journal of General Microbiology, 133 (12), 3581-3590, 1987.
Jahn S et al, "Cell biology of human igm-producing hybridomas derived from a fusion of human spleen lymphocytes with mouse myeloma cells", Hybridoma, 6(6), 679-688, 1987.
Database WPI, Section Ch, Week 9138, Derwent Publications Ltd, London, GB; Class B04, AN 91-277581 XP002007427 & Abstract of JP-A-03 183 477 (Morinaga & Co Ltd), 9 Aug. 1991.
Ishikawa Yuji
Kimachi Kazuhiko
Maeda Hiroaki
Nishiyama Kiyoto
Tokiyoshi Sachio
Chan Christina Y.
Juridical Foundation The Chemo-Sero Therapeutic Research Institu
VanderVegt F. Pierre
LandOfFree
Method for producing exogenous protein does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for producing exogenous protein, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for producing exogenous protein will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1832293