HEK 293 cells

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Human embryonic kidney 293 cells, also often referred to as HEK 293, HEK-293, 293 cells, are an immortalised cell line derived from HEK cells isolated from a female fetus in the 1970s. [1] [2]

Contents

The HEK 293 cell line has been widely used in research for decades due to its reliable and fast growth and propensity for transfection. The cell line is 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.

History

HEK 293 cells were generated in 1973 by transfection of cultures of normal human embryonic kidney cells with sheared adenovirus 5 DNA in Alex van der Eb's laboratory in Leiden, the Netherlands. The cells were obtained from a single, aborted or miscarried fetus, the precise origin of which is unclear. [3] [2] The cells were cultured by van der Eb; the transduction by adenovirus was performed by Frank Graham, a post-doc in van der Eb's lab. They were published in 1977 after Graham left Leiden for McMaster University. [4] They are called HEK since they originated in human embryonic kidney cultures, while the number 293 came from Graham's habit of numbering his experiments; the original HEK 293 cell clone was from his 293rd experiment. Graham performed the transfection a total of eight times, obtaining just one clone of cells that were cultured for several months. After presumably adapting to tissue culture, cells from this clone developed into the relatively stable HEK 293 line.

Subsequent analysis has shown that the transformation was brought about by inserting ~4.5 kilobases from the left arm of the adenoviral genome, which became incorporated into human chromosome 19. [5]

For many years it was assumed that HEK 293 cells were generated by transformation of either a fibroblastic, endothelial or epithelial cell, all of which are abundant in kidneys. However, the original adenovirus transformation was inefficient, suggesting that the cell that finally produced the HEK 293 line may have been unusual in some fashion. Graham and coworkers provided evidence that HEK 293 cells and other human cell lines generated by adenovirus transformation of human embryonic kidney cells have many properties of immature neurons, suggesting that the adenovirus preferentially transformed a neuronal lineage cell in the original kidney culture. [6]

A comprehensive study of the genomes and transcriptomes of HEK 293 and five derivative cell lines compared the HEK 293 transcriptome with that of human kidney, adrenal, pituitary and central nervous tissue. [7] The HEK 293 pattern most closely resembled that of adrenal cells, which have many neuronal properties. Given the location of the adrenal gland (adrenal means "next to the kidney"), a few adrenal cells could plausibly have appeared in an embryonic kidney derived culture, and could be preferentially transformed by adenovirus. Adenoviruses transform neuronal lineage cells much more efficiently than typical human kidney epithelial cells. [6] An embryonic adrenal precursor cell therefore seems the most likely origin cell of the HEK 293 line. As a consequence, HEK 293 cells should not be used as an in vitro model of typical kidney cells.

HEK 293 cells have a complex karyotype, exhibiting two or more copies of each chromosome and with a modal chromosome number of 64. They are described as hypotriploid, containing less than three times the number of chromosomes of a haploid human gamete. Chromosomal abnormalities include a total of three copies of the X chromosomes and four copies of chromosome 17 and chromosome 22. [7] [8] The presence of multiple X chromosomes and the lack of any trace of Y chromosome derived sequence suggest that the source fetus was female.

The 293T cell line was created in Michele Calos's lab at Stanford by stable transfection of the HEK 293 cell line with a plasmid encoding a temperature-sensitive mutant of the SV40 large T antigen; it was originally referred to as 293/tsA1609neo. [9] The first reference to the cell line as "293T" may be its use to create the BOSC23 packaging cell line for producing retroviral particles. [10]

Variants

Multiple variants of HEK 293 have been reported. [11] [12]

HEK 293T

The transfection used to create 293T (involving plasmid pRSV-1609) conferred neomycin/G418 resistance and expression of the tsA1609 allele of SV40 large T antigen; this allele is fully active at 33 °C (its permissive temperature), has substantial function at 37 °C, and is inactive at 40 °C. [14] 293T is very efficiently transfected with DNA (like its parent HEK 293). Due to the expression of SV40 large T antigen, transfected plasmid DNAs that carry the SV40 origin of replication can replicate in 293T and will transiently maintain a high copy number; this can greatly increase the amount of recombinant protein or retrovirus that can be produced from the cells.

The full genome sequences of three different isolates of 293T have been determined. They are quite similar to each other but show detectable divergence from the parental HEK 293 cell line. [15]

HEK293-ENT1KO

This mutant strain does not express of the equilibrative nucleoside transporter ENT1. The gene was knocked out using CRISPR-CAS9 and the cell line retains ENT2 expression. [16]

Applications

Immunofluorescent HEK 293 cells HEK 293.jpg
Immunofluorescent HEK 293 cells

HEK 293 cells are straightforward to grow in culture and to transfect. They have been used as hosts for gene expression. Typically, these experiments involve transfecting in a gene (or combination of genes) of interest, and then analyzing the expressed protein. The widespread use of this cell line is due to its transfectability by the various techniques, including calcium phosphate method, achieving efficiencies approaching 100%.

Examples of such experiments include:

HEK 293 cells were adapted to grow in suspension culture, as opposed to proliferation on plastic plates, in 1985. [22] This enabled the growth of large amounts of recombinant adenovirus vectors.

A more specific use of HEK 293 cells is in the propagation of adenoviral vectors. [23] Viruses offer an efficient means of delivering genes into cells, which they evolved to do, and are thus of great use as experimental tools. However, as pathogens, they also present a risk to the experimenter. This danger can be avoided by the use of viruses which lack key genes, and which are thus unable to replicate after entering a cell. In order to propagate such viral vectors, a cell line that expresses the missing genes is required. Since HEK 293 cells express a number of adenoviral genes, they can be used to propagate adenoviral vectors in which these genes (typically, E1 and E3) are deleted, such as AdEasy. [24] However, homologous recombination between the inserted cellular Ad5 sequence and the vector sequence, although rare, can restore the replication capacity to the vector. [25]

An important variant of this cell line is the 293T cell line. It contains the SV40 large T-antigen that allows for episomal replication of transfected plasmids containing the SV40 origin of replication. This allows for amplification of transfected plasmids and extended temporal expression of desired gene products. HEK 293, and especially HEK 293T, cells are commonly used for the production of various retroviral vectors. [26] Various retroviral packaging cell lines are also based on these cells.

Native proteins of interest

Depending on various conditions, the gene expression of HEK 293 cells may vary. The following proteins of interest (among many others) are commonly found in untreated HEK 293 cells:

Bioethics

Alvin Wong, a catholic bioethicist, argues that despite the uncertainty over the origin of the embryonic cells used to obtain the cell line, one can infer that it came from a voluntary abortion. To some, this may present an ethical dilemma for using HEK 293 and derivative products, such as vaccines and many medications. [31] [32] [33] [34]

On 21 December 2020, the Roman Catholic Congregation for the Doctrine of the Faith stated that the moral duty to avoid vaccines made from cell lines derived from fetuses is, "not obligatory if there is grave danger, such as the otherwise uncontainable spread of a serious pathological event -- in this case, the pandemic spread of SARS-CoV-2 virus that causes Covid-19". The statement then justifies the use of other vaccines, "all vaccinations recognized as clinically safe and effective can be used in good conscience..." [35]

During the COVID-19 pandemic, anti-vaccination activists noted that HEK 293 cells are used in the manufacturing of the Oxford–AstraZeneca COVID-19 vaccine (AKA AZD1222). The cells are filtered out of the final products. [36]

Regeneron Pharmaceuticals, the maker of REGN-COV2, a therapeutic antibody cocktail used to alleviate symptoms of patients with COVID-19, did not use HEK 293T cells to produce the antibody cocktail but did use those cells to assess the potency of the drug. [37] [32]

In response to ethical concerns of vaccine production, several strategies for clinicians to discuss with their patients have been suggested. [38]


See also

Related Research Articles

<span class="mw-page-title-main">DNA vaccine</span> Vaccine containing DNA

A DNA vaccine is a type of vaccine that transfects a specific antigen-coding DNA sequence into the cells of an organism as a mechanism to induce an immune response.

<span class="mw-page-title-main">Protein production</span>

Protein production is the biotechnological process of generating a specific protein. It is typically achieved by the manipulation of gene expression in an organism such that it expresses large amounts of a recombinant gene. This includes the transcription of the recombinant DNA to messenger RNA (mRNA), the translation of mRNA into polypeptide chains, which are ultimately folded into functional proteins and may be targeted to specific subcellular or extracellular locations.

<i>Adenoviridae</i> Family of viruses

Adenoviruses are medium-sized, nonenveloped viruses with an icosahedral nucleocapsid containing a double-stranded DNA genome. Their name derives from their initial isolation from human adenoids in 1953.

<span class="mw-page-title-main">Expression vector</span> Virus or plasmid designed for gene expression in cells

An expression vector, otherwise known as an expression construct, is usually a plasmid or virus designed for gene expression in cells. The vector is used to introduce a specific gene into a target cell, and can commandeer the cell's mechanism for protein synthesis to produce the protein encoded by the gene. Expression vectors are the basic tools in biotechnology for the production of proteins.

Transfection is the process of deliberately introducing naked or purified nucleic acids into eukaryotic cells. It may also refer to other methods and cell types, although other terms are often preferred: "transformation" is typically used to describe non-viral DNA transfer in bacteria and non-animal eukaryotic cells, including plant cells. In animal cells, transfection is the preferred term as transformation is also used to refer to progression to a cancerous state (carcinogenesis) in these cells. Transduction is often used to describe virus-mediated gene transfer into eukaryotic cells.

<span class="mw-page-title-main">SV40</span> Species of virus

SV40 is an abbreviation for simian vacuolating virus 40 or simian virus 40, a polyomavirus that is found in both monkeys and humans. Like other polyomaviruses, SV40 is a DNA virus that sometimes causes tumors in animals, but most often persists as a latent infection. SV40 has been widely studied as a model eukaryotic virus, leading to many early discoveries in eukaryotic DNA replication and transcription.

<span class="mw-page-title-main">Vero cell</span>

Vero cells are a lineage of cells used in cell cultures. The 'Vero' lineage was isolated from kidney epithelial cells extracted from an African green monkey. The lineage was developed on 27 March 1962 by Yasumura and Kawakita at the Chiba University in Chiba, Japan. The original cell line was named Vero after an abbreviation of verdareno, which means 'green kidney' in Esperanto, while vero itself means 'truth' in Esperanto.

<span class="mw-page-title-main">Viral vector</span> Biotechnology to deliver genetic material into a cell

Viral vectors are tools commonly used by molecular biologists to deliver genetic material into cells. This process can be performed inside a living organism or in cell culture. Viruses have evolved specialized molecular mechanisms to efficiently transport their genomes inside the cells they infect. Delivery of genes or other genetic material by a vector is termed transduction and the infected cells are described as transduced. Molecular biologists first harnessed this machinery in the 1970s. Paul Berg used a modified SV40 virus containing DNA from the bacteriophage λ to infect monkey kidney cell maintained in culture.

<span class="mw-page-title-main">COS cells</span> Cell lines derived from monkey kidney tissue

COS are fibroblast-like cell lines derived from monkey kidney tissue. COS cells are obtained by immortalizing CV-1 cells with a version of the SV40 virus that can produce large T antigen but has a defect in genomic replication. The CV-1 cell line in turn was derived from the kidney of the African green monkey.

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<span class="mw-page-title-main">H19 (gene)</span> Negative regulation (or limiting) of body weight and cell proliferation

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<span class="mw-page-title-main">BacMam</span> Use of baculovirus to deliver genes to mammalian cells

Baculovirus gene transfer into Mammalian cells, known from scientific research articles as BacMam, is the use of baculovirus to deliver genes to mammalian cells. Baculoviruses are insect viruses that can be modified to express proteins in mammalian cells. The unmodified baculovirus is able to enter those cells; however, its genes are not expressed unless a mammalian recognizable promoter is incorporated upstream of a gene of interest. Both unmodified baculovirus and its modified counterpart are unable to replicate in humans and are thus non-infectious.

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<span class="mw-page-title-main">Immortalised cell line</span> Lineage of cells that evades senescence and continues dividing

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Transient expression, more frequently referred to "transient gene expression", is the temporary expression of genes that are expressed for a short time after nucleic acid, most frequently plasmid DNA encoding an expression cassette, has been introduced into eukaryotic cells with a chemical delivery agent like calcium phosphate (CaPi) or polyethyleneimine (PEI). However, unlike "stable expression," the foreign DNA does not fuse with the host cell DNA, resulting in the inevitable loss of the vector after several cell replication cycles. The majority of transient gene expressions are done with cultivated animal cells. The technique is also used in plant cells; however, the transfer of nucleic acids into these cells requires different methods than those with animal cells. In both plants and animals, transient expression should result in a time-limited use of transferred nucleic acids, since any long-term expression would be called "stable expression."

<span class="mw-page-title-main">Lex van der Eb</span> Dutch molecular biologist and virologist

Alex Jan"Lex"van der Eb is a Dutch molecular biologist and virologist. He was a professor of fundamental tumor virology and later molecular carcinogenesis at Leiden University from 1979 to 2000. He has performed research in adenoviruses and was fundamental in the creation of the technique of calcium phosphate transfection and the founding of the HEK 293 and PER.C6 cell lines.

<span class="mw-page-title-main">Viral vector vaccine</span> Type of vaccine

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<span class="mw-page-title-main">Intracellular delivery</span> Scientific research area

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References

  1. ↑ Kavsan, Vadym M; Iershov, Anton V; Balynska, Olena V (23 May 2011). "Immortalized cells and one oncogene in malignant transformation: old insights on new explanation". BMC Cell Biology. 12: 23. doi: 10.1186/1471-2121-12-23 . PMC   3224126 . PMID   21605454.
  2. 1 2 Austriaco N (May 25, 2020). "Moral Guidance on Using COVID-19 Vaccines Developed with Human Fetal Cell Lines". Public Discourse. Witherspoon Institute. Retrieved December 23, 2020. I received an e-mail a few months ago from Professor Frank Graham, who established this cell line. He tells me that to the best of his knowledge, the exact origin of the HEK293 fetal cells is unclear. They could have come from either a spontaneous miscarriage or an elective abortion.
  3. ↑ van der Eb A. "USA FDA CTR For Biologics Evaluation and Research Vaccines and Related Biological Products Advisory Committee Meeting" (PDF). Lines 14–22: USFDA. p. 81. Archived from the original (PDF) on 2017-05-16. Retrieved August 11, 2012.{{cite web}}: CS1 maint: location (link)
  4. ↑ Graham FL, Smiley J, Russell WC, Nairn R (July 1977). "Characteristics of a human cell line transformed by DNA from human adenovirus type 5". The Journal of General Virology. 36 (1): 59–74. CiteSeerX   10.1.1.486.3027 . doi:10.1099/0022-1317-36-1-59. PMID   886304.
  5. ↑ Louis N, Evelegh C, Graham FL (July 1997). "Cloning and sequencing of the cellular-viral junctions from the human adenovirus type 5 transformed 293 cell line". Virology. 233 (2): 423–9. doi: 10.1006/viro.1997.8597 . PMID   9217065.
  6. 1 2 Shaw G, Morse S, Ararat M, Graham FL (June 2002). "Preferential transformation of human neuronal cells by human adenoviruses and the origin of HEK 293 cells". FASEB Journal. 16 (8): 869–71. doi: 10.1096/fj.01-0995fje . PMID   11967234. S2CID   6519203.
  7. 1 2 Lin YC, Boone M, Meuris L, Lemmens I, Van Roy N, Soete A, et al. (September 2014). "Genome dynamics of the human embryonic kidney 293 lineage in response to cell biology manipulations". Nature Communications. 5 (8): 4767. Bibcode:2014NatCo...5.4767L. doi:10.1038/ncomms5767. PMC   4166678 . PMID   25182477.
  8. ↑ "ECACC Catalogue Entry for HEK 293". hpacultures.org.uk. ECACC. Archived from the original on 2012-05-02. Retrieved 2012-03-18.
  9. ↑ DuBridge RB, Tang P, Hsia HC, Leong PM, Miller JH, Calos MP (Jan 1987). "Analysis of mutation in human cells by using an Epstein-Barr virus shuttle system". Mol. Cell. Biol. 7 (1): 379–387. doi:10.1128/MCB.7.1.379. PMC   365079 . PMID   3031469.
  10. ↑ Pear WS, Nolan GP, Scott ML, Baltimore D (15 Sep 1993). "Production of high-titer helper-free retroviruses by transient transfection". Proc. Natl. Acad. Sci. USA. 90 (18): 8392–8396. Bibcode:1993PNAS...90.8392P. doi: 10.1073/pnas.90.18.8392 . PMC   47362 . PMID   7690960.
  11. ↑ Abaandou, Laura; Quan, David; Shiloach, Joseph (2021-07-02). "Affecting HEK293 Cell Growth and Production Performance by Modifying the Expression of Specific Genes". Cells. 10 (7): 1667. doi: 10.3390/cells10071667 . ISSN   2073-4409. PMC   8304725 . PMID   34359846.
  12. ↑ Shahid, Nayiar; Chromwell, Christopher; Hubbard, Basil; Hammond, James (May 2021). "Characterization of a Novel HEK293 Cell Line (HEK293-ENT1KO) to Assess the Role of Equilibrative Nucleoside Transporter Subtype-2". The FASEB Journal. 35 (S1). doi: 10.1096/fasebj.2021.35.S1.02185 . ISSN   0892-6638.
  13. ↑ "HEK293 expression platform (L-10894/11266/11565)" (PDF). National Research Council Canada. April 2019.
  14. ↑ Rio DC, Clark SG, Tjian R (4 Jan 1985). "A mammalian host-vector system that regulates expression and amplification of transfected genes by temperature induction". Science. 227 (4682): 23–28. Bibcode:1985Sci...227...23R. doi:10.1126/science.2981116. PMID   2981116.
  15. ↑ Lin YC, Boone M, Meuris L, Lemmens I, Van Roy N, Soete A, Reumers J, Moisse M, Plaisance S, Drmanac R, Chen J, Speleman F, Lambrechts D, Van de Peer Y, Tavernier J, Callewaert N (3 Sep 2014). "Genome dynamics of the human embryonic kidney 293 lineage in response to cell biology manipulations". Nat. Commun. 5. 4767. Bibcode:2014NatCo...5.4767L. doi:10.1038/ncomms5767. PMC   4166678 . PMID   25182477.
  16. ↑ Shahid, Nayiar; Chromwell, Christopher; Hubbard, Basil; Hammond, James (May 2021). "Characterization of a Novel HEK293 Cell Line (HEK293-ENT1KO) to Assess the Role of Equilibrative Nucleoside Transporter Subtype-2". The FASEB Journal. 35 (S1). doi: 10.1096/fasebj.2021.35.S1.02185 . ISSN   0892-6638.
  17. ↑ Fredj S, Sampson KJ, Liu H, Kass RS (May 2006). "Molecular basis of ranolazine block of LQT-3 mutant sodium channels: evidence for site of action". British Journal of Pharmacology. 148 (1): 16–24. doi:10.1038/sj.bjp.0706709. PMC   1617037 . PMID   16520744.
  18. ↑ Amar L, Desclaux M, Faucon-Biguet N, Mallet J, Vogel R (March 2006). "Control of small inhibitory RNA levels and RNA interference by doxycycline induced activation of a minimal RNA polymerase III promoter". Nucleic Acids Research. 34 (5): e37. doi:10.1093/nar/gkl034. PMC   1390691 . PMID   16522642.
  19. ↑ Kanno T, Yamamoto H, Yaguchi T, Hi R, Mukasa T, Fujikawa H, et al. (June 2006). "The linoleic acid derivative DCP-LA selectively activates PKC-epsilon, possibly binding to the phosphatidylserine binding site". Journal of Lipid Research. 47 (6): 1146–56. doi: 10.1194/jlr.M500329-JLR200 . PMID   16520488.
  20. ↑ Li T, Paudel HK (March 2006). "Glycogen synthase kinase 3beta phosphorylates Alzheimer's disease-specific Ser396 of microtubule-associated protein tau by a sequential mechanism". Biochemistry. 45 (10): 3125–33. doi:10.1021/bi051634r. PMID   16519507.
  21. ↑ Mustafa H, Strasser B, Rauth S, Irving RA, Wark KL (April 2006). "Identification of a functional nuclear export signal in the green fluorescent protein asFP499". Biochemical and Biophysical Research Communications. 342 (4): 1178–82. doi:10.1016/j.bbrc.2006.02.077. PMID   16516151.
  22. ↑ Stillman BW, Gluzman Y (August 1985). "Replication and supercoiling of simian virus 40 DNA in cell extracts from human cells". Molecular and Cellular Biology. 5 (8): 2051–60. doi: 10.1128/mcb.5.8.2051 . PMC   366923 . PMID   3018548.
  23. ↑ Thomas P, Smart TG (2005). "HEK293 cell line: a vehicle for the expression of recombinant proteins". Journal of Pharmacological and Toxicological Methods. 51 (3): 187–200. doi:10.1016/j.vascn.2004.08.014. PMID   15862464.
  24. ↑ He TC, Zhou S, da Costa LT, Yu J, Kinzler KW, Vogelstein B (March 1998). "A simplified system for generating recombinant adenoviruses". Proc Natl Acad Sci U S A. 95 (5): 2509–14. Bibcode:1998PNAS...95.2509H. doi: 10.1073/pnas.95.5.2509 . PMC   19394 . PMID   9482916.
  25. ↑ Kovesdi, I; Hedley, SJ (August 2010). "Adenoviral producer cells". Viruses. 2 (8): 1681–703. doi: 10.3390/v2081681 . PMC   3185730 . PMID   21994701.
  26. ↑ Fanelli A (2016). "HEK293 Cell Line: human embryonic kidney cells" . Retrieved 3 December 2017.
  27. ↑ Dautzenberg FM, Higelin J, Teichert U (February 2000). "Functional characterization of corticotropin-releasing factor type 1 receptor endogenously expressed in human embryonic kidney 293 cells". European Journal of Pharmacology. 390 (1–2): 51–9. doi:10.1016/S0014-2999(99)00915-2. PMID   10708706.
  28. ↑ Meyer zu Heringdorf D, Lass H, Kuchar I, Lipinski M, Alemany R, Rümenapp U, Jakobs KH (March 2001). "Stimulation of intracellular sphingosine-1-phosphate production by G-protein-coupled sphingosine-1-phosphate receptors". European Journal of Pharmacology. 414 (2–3): 145–54. doi:10.1016/S0014-2999(01)00789-0. PMID   11239914.
  29. ↑ Luo J, Busillo JM, Benovic JL (August 2008). "M3 muscarinic acetylcholine receptor-mediated signaling is regulated by distinct mechanisms". Molecular Pharmacology. 74 (2): 338–47. doi:10.1124/mol.107.044750. PMC   7409535 . PMID   18388243.
  30. ↑ Zagranichnaya TK, Wu X, Villereal ML (August 2005). "Endogenous TRPC1, TRPC3, and TRPC7 proteins combine to form native store-operated channels in HEK-293 cells". The Journal of Biological Chemistry. 280 (33): 29559–69. doi: 10.1074/jbc.M505842200 . PMID   15972814.
  31. ↑ Wong A (2006). "The ethics of HEK 293". The National Catholic Bioethics Quarterly. 6 (3): 473–95. doi:10.5840/ncbq20066331. PMID   17091554.
  32. 1 2 Schorr I (20 December 2020). "The Facts about the COVID Vaccines and Fetal Cell Lines". National Review.
  33. ↑ "Balkan Insight: Tulpina religioasă a anti-vaccinismului se răspândește în Europa Centrală și de Est - International - HotNews.ro". 20 January 2021.
  34. ↑ RELIGIOUS STRAIN OF ANTI-VAX GROWS IN CEE, balkaninsight.com
  35. ↑ "Nota della Congregazione per la Dottrina della Fede sulla moralità dell'uso di alcuni vaccini anti-Covid-19". press.vatican.va. Retrieved 2024-03-06.
  36. ↑ Rahman G (26 November 2020). "There are no foetal cells in the AstraZeneca Covid-19 vaccine". Full Fact.
  37. ↑ Regalado, Antonio (7 October 2020). "Trump's antibody treatment was tested using cells originally derived from an abortion". MIT Technology Review. Retrieved 2021-09-30. It's how you want to parse it," says Alexandra Bowie, a Regeneron spokesperson. "But the 293T cell lines available today are not considered fetal tissue
  38. ↑ Zimmerman, Richard K. (2021-07-13). "Helping patients with ethical concerns about COVID-19 vaccines in light of fetal cell lines used in some COVID-19 vaccines". Vaccine. 39 (31): 4242–4244. doi:10.1016/j.vaccine.2021.06.027. ISSN   1873-2518. PMC   8205255 . PMID   34172329.
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