Hi All
I was discussing HEK-293 cells with another researcher to see if we could find an open cell line and here is what I came up with.
Background
From Wikipedia, the free encyclopedia
Human embryonic kidney 293 cells, also often referred to as HEK 293, HEK-293, 293 cells, or less precisely as HEK cells, are a specific immortalised cell line derived from a spontaneously miscarried or aborted fetus or human embryonic kidney cells grown in tissue culture taken from a female fetus in 1973.[1][2]
HEK 293 cells have been widely used in cell biology research for many years, because of their reliable growth and propensity for transfection. They are also used by the biotechnology industry to produce therapeutic proteins and viruses for gene therapy as well as safety testing for a vast array of chemicals.
293T (or HEK 293T) is a derivative human cell line that expresses a mutant version of the SV40 large T antigen. It is very commonly used in biological research for making proteins and producing recombinant retroviruses.
Finding an open cell line
I spent some time tracing the “family history” of HEK cells via patents and papers and most of them are tricky because the original line was deposited by Frank Graham with ATCC very early, and therefore most derivatives trace back to ATCC. I think I have found a stray though… FreeStyle™ HEK cells.
Here is the patent: US 7217566 B2 - Attached cell lines - The Lens - Free & Open Patent and Scholarly Search
Commercial product: FreeStyle™ 293-F-Zellen
Cellosaurus entry: Cellosaurus cell line FreeStyle 293-F (CVCL_D603)
The patent expires next month (!) and it was deposited with ATCC as PTA5080 - patent deposits are not publicly listed so you won’t find this on the website.
There are some other lines covered in the same patent but they derive from GIBCO cells, this one I think is both traceable but has no MTA trail
Traceability and Provenance
Text from the patent:
Generation of the FreeStyle™ 293 Cell Line
[0228] In order to facilitate human biochemical expression, a subclone of HEK 293, an optimized media formulation and a transfection reagent for expression of biologically active materials in a scalable suspension format were developed. HEK 293-F cells were obtained from Robert Horlick at Pharmacopoeia. A fast-growing variant was isolated and adapted to growth in serum free suspension culture, unfortunately the media that the cells were adapted to does not allow transfection. Several fast growing clones were adapted into adherent culture. Sub-clones were isolated and screened for efficient transfection and high protein production. These cells, after adaptation, demonstrated characteristics of rapid growth and ease of transfection. This subclone was adapted into FreeStyle™ 293 Expression Medium and named FreeStyle™ 293 cells. The FreeStyle™ 293 cells are grown in suspension for ease of use and were not transfected with the MSR gene.
Below is info from: Host Cells and Cell Banking | SpringerLink
5.1.1 Traceability
The traceability of HEK293 is not excellent. Although they have been established in 1977, the passages during the first years after the establishment have not really been traced. Only more recently established subclones have a certain traceability that is often sufficient for clinical studies.
As an example, the traceability of 293FT cells is presented here. The real traceability starts with 1988 when Life Technologies got the HEK293 cells from R. Horlick via R. Swanson (both from Pharmacopeia in the USA). Today, it is practically impossible to trace back the way how the cells came from Graham’s lab in Canada to Pharmacopeia.
In 1998, Life Technologies selected the 293F cells (“fast-growing” clone of HEK293), and 1 year later Life Technologies generated the 293FT cells after having stably transfected the 293F cells with pCMVSPORT6Tag.neo for overexpressing the SV40 T antigen (the expression of the SV40 T antigen is controlled by the human CMV promoter (→ high level, constitutive expression). The gene encoding the SV40 T antigen permits the episomal replication of plasmids containing the SV40 early promoter and origin. Today, the cells are available from Invitrogen and are traceable back to 1988.
Since 1988, these cells are traceable for the medium and serum (USDA approved) used; no trypsin was used since 1988.
Looks like the MTA trail goes cold…Pharmacopeia got sold off in 2008 and I can find no evidence that the buyer Ligand Pharmaceuticals have any connection to these cells.
How to Request the Cells
According to the WIPO Guide to the Deposit of Microorganisms under the Budapest Treaty “In the United States of America, in general, after grant any microorganism referred to in the published patent must be available to the public without restriction.” I am taking “without restriction” literally but I’d be interested to see what ATCC provide in terms of paperwork to requestors, and also get a legal opinion.
In principle you can just email ATCC to request the sample of cells but they might want a form completed “To obtain a sample pursuant to Rule ll.3(b), a requesting party merely needs to give his name and address and quote the accession number of the microorganism. Some IDAs, however, request use of WIPO model form BP/13.” ATCC could also hold them back to check you can safely use them “Notwithstanding any entitlement of third parties to receive samples under patent regulations, the ATCC will withhold samples of organisms that are subject to health and safety regulations until it has confirmed that the requesting party can comply with such regulations.”
The cost, presumably minus shipping, will be 330 USD according to the ATCC info provided to WIPO.
The email address is PatentDeposit [at] atcc.org and I would send form BP/13 and a PDF copy of the granted patent. They could ask you to complete Form BP/12 which you first have to get signed off by a Director of the USPTO TC 1600.
Next Steps
We are requesting the cells and will report back…