Patent US1960476A successfully refreshed from Google Patents.
Patent US6995009B1 successfully refreshed from Google Patents.
US6995009B1
Expired / Lapsed
US
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Packaging cell
Assignee: Chugai Pharmaceutical Co Ltd
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Filing: 2000-06-01
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Granted: 2006-02-07
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Expires: 2020-06-01
Abstract
Abstract A virus-producing cell sustaining the ability to produce viruses at high titer is successfully constructed by expressing the virus structural gene under the regulation of EF1α promoter. In this virus-producing cell, the virus structural gene is ligated to a selection marker gene via IRES and domains other than the protein coding domain are eliminated from the DNA encoding virus structural proteins. Thus, reduction of the titer due to cell passages can be prevented and emergence of wild type viruses caused by unfavorable recombination of the virus genome can be inhibited.
Inventors
- 👤 Toshio Kitamura
- 👤 Sumiyo Morita
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 20:35
CPC Classifications
C; C07; C07K; C07K14/00; C07K14/005; C12; C12N; C12N7/00; C12N2740/00; C12N2740/00011; C12N2740/10011; C12N2740/10022; C12N2740/10051; C12N2740/10052
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
33 words
A 293T cell useful for the production of retroviruses, wherein the cell contains an expression construct comprising DNA encoding gag, pol, and env retroviral structural proteins operably linked downstream of an EF1α promoter.
Claim 2
Dependent Claim
33 words
A 293T cell useful for the production of retroviruses, wherein the cell contains an expression construct comprising DNA encoding gag, pol, and env retroviral structural proteins operably linked downstream of an EF1α promoter.
Claim 3
Dependent Claim
45 words
A 293T cell useful for the production of retroviruses by expressing retroviral structural proteins gag, pol and env, wherein the cell comprises a first expression construct expressing gag and pol from an EF1α promoter, and a second expression construct expressing env from an EF1α promoter.
Claim 4
Dependent Claim
45 words
A 293T cell useful for the production of retroviruses by expressing retroviral structural proteins gag, pol and env, wherein the cell comprises a first expression construct expressing gag and pol from an EF1α promoter, and a second expression construct expressing env from an EF1α promoter.
Claim 5
Dependent Claim
21 words
The cell according to claim 1 , wherein the env is derived from either an ecotropic retrovirus or an amphotropic retrovirus.
Claim 6
Dependent Claim
23 words
A cell specified by Accession No. FERM BP-6737 or FERM BP-6977 as deposited at the National Institute of Bioscience and Human-Technology in Japan.
Claim 7
Dependent Claim
23 words
A cell specified by Accession No. FERM BP-6737 or FERM BP-6977 as deposited at the National Institute of Bioscience and Human-Technology in Japan.
Claim 8
Dependent Claim
32 words
The cell according to claim 1 , wherein a Kozak's consensus sequence is located upstream of a translation initiation codon of the DNA encoding the retroviral structural proteins in the expression construct.
Claim 9
Dependent Claim
28 words
The cell according to claim 1 , wherein the DNA encoding the retroviral structural proteins is linked to a DNA encoding a selective marker via an IRES sequence.
Claim 10
Dependent Claim
31 words
The cell according to claim 1 , wherein the DNA encoding the retroviral structural proteins is substantially free from virus genome-derived DNA other than the DNA encoding gag, pol, and env.
Claim 11
Dependent Claim
31 words
A method for producing a retrovirus, the method comprising the step of introducing into the cell of claim 1 a retroviral vector DNA that lacks sequence encoding gag, pol, and env.
Claim 12
Dependent Claim
20 words
The method according to claim 8 , in which a foreign coding sequence is included in the retroviral vector DNA.
Claim 13
Dependent Claim
21 words
The cell according to claim 2 , wherein the env is derived from either an ecotropic retrovirus or an amphotropic retrovirus.
Claim 14
Dependent Claim
37 words
The cell according to claim 2 , wherein a Kozak's consensus sequence is located upstream of a translation initiation codon of the DNA encoding the retroviral structural proteins in each of the first and second expression constructs.
Claim 15
Dependent Claim
37 words
The cell according to claim 2 , wherein the DNA encoding the retroviral structural proteins in each of the first and second expression constructs is linked to a DNA encoding a selective marker via an IRES sequence.
Claim 16
Dependent Claim
38 words
The cell according to claim 2 , wherein the DNA encoding the retroviral structural proteins in the first and second expression constructs is substantially free from virus genome-derived DNA other than the DNA encoding gag, pol, and env.
Claim 17
Dependent Claim
31 words
A method for producing a retrovirus, the method comprising the step of introducing into the cell of claim 2 a retroviral vector DNA that lacks sequence encoding gag, pol, and env.
Claim 18
Dependent Claim
20 words
The method according to claim 14 , in which a foreign coding sequence is included in the retroviral vector DNA.
Claim 19
Dependent Claim
31 words
A method for producing a retrovirus, the method comprising the step of introducing into the cell of claim 4 a retroviral vector DNA that lacks sequence encoding gag, pol, and env.
Claim 20
Dependent Claim
20 words
The method according to claim 16 , in which a foreign coding sequence is included in the retroviral vector DNA.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2009-02-06 | 2009-08-08 | 2010-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2013-02-06 | 2013-08-08 | 2014-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2017-02-06 | 2017-08-08 | 2018-02-07 | $7700.00 | Window Closed / Lapsed |