Novel cell lines derived from Chinese hamster kidney tissue

Yoshinori Kawabe; Masamichi Kamihira

doi:10.1371/journal.pone.0266061

Peer Review History

Original SubmissionJanuary 5, 2022
28 Jan 2022 Decision Letter - Wuqiang Zhu, Editor PONE-D-22-00223Novel cell lines derived from Chinese hamster kidney tissuePLOS ONE Dear Dr. Kamihira, Thank you for submitting your manuscript to PLOS ONE. After careful consideration, we feel that it has merit but does not fully meet PLOS ONE’s publication criteria as it currently stands. Therefore, we invite you to submit a revised version of the manuscript that addresses the points raised during the review process. ============================== ACADEMIC EDITOR: Please include additional data to characterize the cell line, and add more information about methodology as requested by the reviewers. ============================== Please submit your revised manuscript by Mar 14 2022 11:59PM. If you will need more time than this to complete your revisions, please reply to this message or contact the journal office at plosone@plos.org. When you're ready to submit your revision, log on to https://www.editorialmanager.com/pone/ and select the 'Submissions Needing Revision' folder to locate your manuscript file. Please include the following items when submitting your revised manuscript: A rebuttal letter that responds to each point raised by the academic editor and reviewer(s). You should upload this letter as a separate file labeled 'Response to Reviewers'. A marked-up copy of your manuscript that highlights changes made to the original version. You should upload this as a separate file labeled 'Revised Manuscript with Track Changes'. An unmarked version of your revised paper without tracked changes. You should upload this as a separate file labeled 'Manuscript'. If you would like to make changes to your financial disclosure, please include your updated statement in your cover letter. Guidelines for resubmitting your figure files are available below the reviewer comments at the end of this letter. If applicable, we recommend that you deposit your laboratory protocols in protocols.io to enhance the reproducibility of your results. Protocols.io assigns your protocol its own identifier (DOI) so that it can be cited independently in the future. For instructions see: https://journals.plos.org/plosone/s/submission-guidelines#loc-laboratory-protocols. Additionally, PLOS ONE offers an option for publishing peer-reviewed Lab Protocol articles, which describe protocols hosted on protocols.io. Read more information on sharing protocols at https://plos.org/protocols?utm_medium=editorial-email&utm_source=authorletters&utm_campaign=protocols. We look forward to receiving your revised manuscript. Kind regards, Wuqiang Zhu, MD, PhD Academic Editor PLOS ONE Journal Requirements: When submitting your revision, we need you to address these additional requirements. 1. Please ensure that your manuscript meets PLOS ONE's style requirements, including those for file naming. The PLOS ONE style templates can be found at https://journals.plos.org/plosone/s/file?id=wjVg/PLOSOne_formatting_sample_main_body.pdf and https://journals.plos.org/plosone/s/file?id=ba62/PLOSOne_formatting_sample_title_authors_affiliations.pdf 2. To comply with PLOS ONE submissions requirements, in your Methods section, please provide additional information regarding the experiments involving animals and ensure you have included details on (1) methods of sacrifice, (2) methods of anesthesia and/or analgesia, and (3) efforts to alleviate suffering. 3. We note that you have included the phrase “data not shown” in your manuscript. Unfortunately, this does not meet our data sharing requirements. PLOS does not permit references to inaccessible data. We require that authors provide all relevant data within the paper, Supporting Information files, or in an acceptable, public repository. Please add a citation to support this phrase or upload the data that corresponds with these findings to a stable repository (such as Figshare or Dryad) and provide and URLs, DOIs, or accession numbers that may be used to access these data. Or, if the data are not a core part of the research being presented in your study, we ask that you remove the phrase that refers to these data. [Note: HTML markup is below. Please do not edit.] Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Partly Reviewer #2: Yes ******** 2. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: I Don't Know Reviewer #2: Yes ****** 3. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: No Reviewer #2: Yes ****** 4. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: • In the chapter of result, the authors referred “Initially, the cells were a mixture of fibroblasts and epithelial cells (S1 Fig). On day 31 of culture after the seventh passage, the cell population was mostly composed of epithelial cells (S1 Fig).” The author just shows the bright field pictures of the cells, and does not prove the properties of the cells through some specific markers. If some immunofluorescence staining pictures of fibroblast markers such as alpha Smooth Muscle Actin and epithelial cell markers such as cytokeratins or E-cadherin can be provided it will be more convincing. • How the authors got the cell proliferation curve of FIGURE 1C and 1D? The authors may have briefly described the cell seeding method for this experiment. But I did not find information about data collection. I think it should be stated in the chapter of MATERIALS AND METHODS. • The authors referred “the expression of CD24 and CD133 [30], which are renal stem cell markers, was increased, and CD24 expression was maintained at a high level even after immortalization (Fig 3D).”, About the expression of CD24 and CD133 it would be more intuitive and convincing if the authors could add immunofluorescence staining experiments, the bar graphs of qPCR and western blot can be more intuitive and convincing. • The authors referred “The immortalization might be caused by increased gene expression fluctuation and activation of proto-oncogenes, suggesting that CHK cells are derived from renal stem cells.“ The analysis of the causes of spontaneous immortalization in this cell line is overly dependent on the results of DNA microarray. If the authors can proceed further study about the relation between proto-oncogenes and cell immortalization I believe the article will be very interesting. Reviewer #2: Immortalized cell lines exhibit a high level of genetic and phenotypic diversity and instability. In the current study, the authors established a new immortalized kidney cell lines from Chinese hamster tissue. They analyzed the phenotypic changes that occurred during the immortalization of kidney cells derived from Chinese hamster tissue in terms of karyotype and gene expression profiles. The paper is well written. The Introduction and Discussion sections provide useful information for the readers. It seems to me an original work and of high applicability. There are several issues the authors need to address to improve the manuscript. 1. The authors detect the expression of CD24 and CD133, which are renal stem cell markers. Did the authors detect other renal stem cell marker genes? There is not enough evidence to suggest CHK-Q cells might be transformed from renal stem cells. 2. The authors established a new immortalized kidney cell lines from Chinese hamster tissue. What is the advantage of these new immortalized kidney cell lines? What is the application of CHK-Q cells? 3. The chromosomes bear structural abnormality and undergo changes in structure and number during cell proliferation in CHK-Q cells. The cell line is unstable and may lose productivity over time in the manufacturing process. In the manuscript, the authors suggest the cell line could be used as a host for the production of biopharmaceuticals, alongside CHO cells and other kidney-derived cell lines. Did the authors detect productivity (for example: lentivirus package) over time in the lab? 4. In lines 150-151: “Data were quantified using Feature Extraction software (Agilent Technologies) and normalized using R statistical processing software.” How do the authors normalize the DNA microarray data? Is raw intensity data for each experiment log10 transformed and then used for the calculation of Z scores? 5. In lines 263-265: “(PCA) showed that the primary cells were different to CHK-Q cells and completely different to the CHO-K1 cells used as a control (Fig 3A). A similar tendency was observed in the heat map analysis (Fig 3B).” However, it is not easy to find this tendency in Fig 3B. 6. These figures are low-resolution images. Figure legends maybe can separately from Results part on a page, at the end of the manuscript. ****** 6. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review?** For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: No [NOTE: If reviewer comments were submitted as an attachment file, they will be attached to this email and accessible via the submission site. Please log into your account, locate the manuscript record, and check for the action link "View Attachments". If this link does not appear, there are no attachment files.] While revising your submission, please upload your figure files to the Preflight Analysis and Conversion Engine (PACE) digital diagnostic tool, https://pacev2.apexcovantage.com/. PACE helps ensure that figures meet PLOS requirements. To use PACE, you must first register as a user. Registration is free. Then, login and navigate to the UPLOAD tab, where you will find detailed instructions on how to use the tool. If you encounter any issues or have any questions when using PACE, please email PLOS at figures@plos.org. Please note that Supporting Information files do not need this step. https://doi.org/10.1371/journal.pone.0266061.r001
Revision 1
9 Mar 2022 Author Response Response to Academic Editor: Comment: Please include additional data to characterize the cell line, and add more information about methodology as requested by the reviewers. Response: We have addressed all the comments raised by the reviewers. We hope that our explanations and revisions are satisfactory. In addition, we re-confirmed the journal requirements: 1) PLOS ONE’s style requirements, 2) the experiments involving animals and 3) data not shown. In the experiments involving animals, we have not bred animals and kidney tissues were purchased from the laboratory animal supplier (Charles River Laboratories, Japan). According to the supplier company, female Chinese hamsters were sacrificed by exsanguination under deep anesthesia before harvesting the kidneys, and the animal experiment was conducted under the ethical principles and guidelines in the company. The sentences have been included in the manuscript (Page 8, Line 116). We removed the “data not shown” phrases and provided the related results as supplementary figures (S6-S8 Figs). To Reviewer 1: Thank you very much for the valuable comments that helped us to improve our paper. According to your comments, we revised the manuscript. Comment 1: In the chapter of result, the authors referred “Initially, the cells were a mixture of fibroblasts and epithelial cells (S1 Fig). On day 31 of culture after the seventh passage, the cell population was mostly composed of epithelial cells (S1 Fig).” The author just shows the bright field pictures of the cells, and does not prove the properties of the cells through some specific markers. If some immunofluorescence staining pictures of fibroblast markers such as alpha Smooth Muscle Actin and epithelial cell markers such as cytokeratins or E-cadherin can be provided it will be more convincing. Response 1: Thank you for the comment. Since it is difficult to obtain anti-Chinese hamster antibodies for specific marker proteins, commercially available anti-mouse antibodies (alpha smooth muscle actin [#ab7817, Abcam] and cytokeratin 19 [#ab220193, Abcam]) were used for immunostaining. Unfortunately, however, these antibodies did not react with Chinese hamster-derived proteins. The heterogeneity of cells during early stage of passage culture was also confirmed by RT-PCR of marker genes specific for epithelial cells and fibroblasts, as shown in Figure A. Fibroblast marker genes (Collagen 1 A1, aSMA and Vinentin) and epithelial marker genes (E-cadherin, Cytokeratin19 and EpCAM) were clearly detected in cells from the second passage, while fibroblast marker genes of Collagen 1 A1 and aSMA were not detected in cells from the ninth passage. Figure A. RT-PCR analysis for fibroblast and epithelial marker genes. Lane M, phiX-174-HincII digest; Lane 1, distilled water; Lane 2, 2nd passage; Lane 3, 9th passage. Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene was used as an internal control. Comment 2: How the authors got the cell proliferation curve of FIGURE 1C and 1D? The authors may have briefly described the cell seeding method for this experiment. But I did not find information about data collection. I think it should be stated in the chapter of MATERIALS AND METHODS. Response 2: According to your suggestion, we added the following sentences in Page 7, Line 101. (Page 7, Line 101) To measure cell proliferation curves, cells were seeded on 24-well tissue culture plates coated with collagen type I (AGC Techno Glass) at a cell density of 2.0 × 104 cells/well in 1.0 mL of DF medium and cultured in adherent conditions for 4 days. For suspension culture, cells were seeded in 125-mL Erlenmeyer flasks at a cell density of 2.0 × 105 cells/mL in 30 mL of CHO-S-SFMII medium and cultured under swirling for 4 days. All culture conditions were prepared in triplicate. Viable cell density was determined by the trypan blue exclusion method. Comment 3: The authors referred “the expression of CD24 and CD133 [30], which are renal stem cell markers, was increased, and CD24 expression was maintained at a high level even after immortalization (Fig 3D).”, About the expression of CD24 and CD133 it would be more intuitive and convincing if the authors could add immunofluorescence staining experiments, the bar graphs of qPCR and western blot can be more intuitive and convincing. Response 3: We have tried immunostaining of CD24 and CD133 on CHK cells using commercially available anti-mouse CD24 antibodies (#MA5-11828, Invitrogen; #130-110-825, Miltenyi Biotec) and anti-rat or rabbit CD133 antibodies (#14-1331-82, Invitrogen or #NB120-16518, Miltenyi Biotec, respectively). However, these antibodies failed to recognize Chinese hamster targets. According to your suggestion, we evaluated CD24/CD133 expression in CHK cells by qRT-PCR (Fig 3D). CD24 and CD133 were expressed in immortalized CHK-Q cells at least 4- and 19-fold higher than in primary cells, respectively. We added the related sentences in Page 11, 175, Page 17, Line 289 and Page 18, Line 307. (Page 11, Line 175) For quantitative RT-PCR analysis, total RNA of cells was extracted and reverse-transcribed into cDNA using reverse-transcriptase and oligo-dT primers. cDNAs were mixed with corresponding primers (S1 Table) and quantitative PCR reagent (Thunderbird SYBR qPCR Mix, Toyobo) in accordance with the manufacturer’s instructions. PCR was performed using a quantitative PCR device (QuantStudio3, Applied Biosystems, Waltham, MA, USA) under the following conditions: 95°C for 1 min, followed by 45 cycles of amplification at 95°C for 15 s, 58°C for 15 s, and 72°C for 30 s, with a final cycle of amplification for melting curve analysis at 95°C for 30 s, 58°C for 30 s, and 95°C for 30 s. The fold change in the CD24 and CD133 specific transcripts relative to the glyceraldehyde-3-phosphate dehydrogenase (GAPDH) endogenous control gene was determined by the ΔΔCt method. The mRNA expression levels were expressed as mean values with standard deviations. (Page 17, Line 289) By quantitative RT-PCR analysis, the expression levels of CD24 and CD133 in immortalized CHK-Q cells were increased by at least 4- and 19-fold, respectively, compared with those in primary cells (Fig 3D). (Page 18, Line 307) (D) Expression analysis of kidney stem cell markers (CD24 and CD133) by quantitative RT-PCR. Data are expressed as mean ± SD (n = 3). Comment 4: The authors referred “The immortalization might be caused by increased gene expression fluctuation and activation of proto-oncogenes, suggesting that CHK cells are derived from renal stem cells.“ The analysis of the causes of spontaneous immortalization in this cell line is overly dependent on the results of DNA microarray. If the authors can proceed further study about the relation between proto-oncogenes and cell immortalization I believe the article will be very interesting. Response 4: Thank you for the comment. However, the detailed relation between immortalization and proto-oncogene expression is still unclear and further study should be needed. To Reviewer 2: We would like to appreciate your comments that helped us to improve our manuscript. We revised the manuscript according to your comments. Comment 1: The authors detect the expression of CD24 and CD133, which are renal stem cell markers. Did the authors detect other renal stem cell marker genes? There is not enough evidence to suggest CHK-Q cells might be transformed from renal stem cells. Response 1: Relative expression profiles of renal stem cell marker genes from the DNA microarray data are summarized in Fig. S6. We added the following sentences in Page 17, Line 291. (Page 17, Line 291) The elevated expression of other renal stem cell marker genes such as paired box 2 (PAX2), paired box 8 (PAX8), homeobox B7 (HOXB7) and CBP/p300 interacting transactivator with Glu/Asp rich carboxy-terminal domain 1 (CITED1) [33,34] was detected in immortalized CHK cells (S6 Fig). Comment 2: The authors established a new immortalized kidney cell lines from Chinese hamster tissue. What is the advantage of these new immortalized kidney cell lines? What is the application of CHK-Q cells? Response 2: Thank you for this comment. We observed renal cyst-like structure formation in a gel sandwich culture of CHK-Q cells. Renal cyst-like structure formation has not been reported using other kidney-derived cell lines. We think that CHK-Q cells can be used to construct a renal cyst model for evaluating cell polarity and drug transport in kidney. We do not intend to include the results in this paper, but this will be reported in the future. Comment 3: The chromosomes bear structural abnormality and undergo changes in structure and number during cell proliferation in CHK-Q cells. The cell line is unstable and may lose productivity over time in the manufacturing process. In the manuscript, the authors suggest the cell line could be used as a host for the production of biopharmaceuticals, alongside CHO cells and other kidney-derived cell lines. Did the authors detect productivity (for example: lentivirus package) over time in the lab? Response 3: Although CHK-Q cells have not been applied to lentivirus production, recombinant antibody genes have been introduced into CHK-Q cells. Recombinant CHK-Q cells showed stable production of the target protein, demonstrating that CHK-Q cells can be used as host cells for producing biopharmaceutical proteins. These data will be published in the future. Comment 4: In lines 150-151: “Data were quantified using Feature Extraction software (Agilent Technologies) and normalized using R statistical processing software.” How do the authors normalize the DNA microarray data? Is raw intensity data for each experiment log10 transformed and then used for the calculation of Z scores? Response 4: Data were quantified using Feature Extraction software (Agilent Technologies). The raw signal intensities of samples were log2-transformed and normalized by a quantile algorithm in the preprocessCore library package on Bioconductor software [28,29]. According to your suggestion, we modified the related sentences and added the following sentences in Page 10, Line 160, together with the references. (Page 10, Line 160) Data were quantified using Feature Extraction software (Agilent Technologies). The raw signal intensities of samples were normalized by a quantile algorithm in the preprocessCore library package on Bioconductor software [28,29]. (References) 28. Bolstad BM, Irizarry RA, Astrand M, Speed TP. A comparison of normalization methods for high density oligonucleotide array data based on variance and bias. Bioinformatics 2003;19:185-193. 29. Gentleman RC, Carey VJ, Bates DM, Bolstad B, Dettling M, Dudoit S, et al. Bioconductor: open software development for computational biology and bioinformatics. Genome Biol. 2004;5:R80. Comment 5: In lines 263-265: “(PCA) showed that the primary cells were different to CHK-Q cells and completely different to the CHO-K1 cells used as a control (Fig 3A). A similar tendency was observed in the heat map analysis (Fig 3B).” However, it is not easy to find this tendency in Fig 3B. Response 5: Hierarchical clustering using the Pearson's correlation distance/average linkage method was added on heatmap in Fig 3B. (Page 18, Line 305) Hierarchical clustering was analyzed using the Pearson's correlation distance/average linkage method. Comment 6: These figures are low-resolution images. Figure legends maybe can separately from Results part on a page, at the end of the manuscript. Response 6: High resolution images can be downloaded from the journal homepage. The download link can be found in each figure. Regarding the preparation of figure legends, we followed the journal’s instructions. Attachments Attachment Submitted filename: Response to Reviewers_0309.docx https://doi.org/10.1371/journal.pone.0266061.r002
14 Mar 2022 Decision Letter - Wuqiang Zhu, Editor Novel cell lines derived from Chinese hamster kidney tissue PONE-D-22-00223R1 Dear Dr. Kamihira, We’re pleased to inform you that your manuscript has been judged scientifically suitable for publication and will be formally accepted for publication once it meets all outstanding technical requirements. Within one week, you’ll receive an e-mail detailing the required amendments. When these have been addressed, you’ll receive a formal acceptance letter and your manuscript will be scheduled for publication. An invoice for payment will follow shortly after the formal acceptance. To ensure an efficient process, please log into Editorial Manager at http://www.editorialmanager.com/pone/, click the 'Update My Information' link at the top of the page, and double check that your user information is up-to-date. If you have any billing related questions, please contact our Author Billing department directly at authorbilling@plos.org. If your institution or institutions have a press office, please notify them about your upcoming paper to help maximize its impact. If they’ll be preparing press materials, please inform our press team as soon as possible -- no later than 48 hours after receiving the formal acceptance. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information, please contact onepress@plos.org. Kind regards, Wuqiang Zhu, MD, PhD Academic Editor PLOS ONE Additional Editor Comments (optional): Reviewers' comments: Reviewer's Responses to Questions Comments to the Author 1. If the authors have adequately addressed your comments raised in a previous round of review and you feel that this manuscript is now acceptable for publication, you may indicate that here to bypass the “Comments to the Author” section, enter your conflict of interest statement in the “Confidential to Editor” section, and submit your "Accept" recommendation. Reviewer #1: All comments have been addressed Reviewer #2: All comments have been addressed ******** 2. Is the manuscript technically sound, and do the data support the conclusions? The manuscript must describe a technically sound piece of scientific research with data that supports the conclusions. Experiments must have been conducted rigorously, with appropriate controls, replication, and sample sizes. The conclusions must be drawn appropriately based on the data presented. Reviewer #1: Yes Reviewer #2: Yes ****** 3. Has the statistical analysis been performed appropriately and rigorously? Reviewer #1: Yes Reviewer #2: Yes ****** 4. Have the authors made all data underlying the findings in their manuscript fully available? The PLOS Data policy requires authors to make all data underlying the findings described in their manuscript fully available without restriction, with rare exception (please refer to the Data Availability Statement in the manuscript PDF file). The data should be provided as part of the manuscript or its supporting information, or deposited to a public repository. For example, in addition to summary statistics, the data points behind means, medians and variance measures should be available. If there are restrictions on publicly sharing data—e.g. participant privacy or use of data from a third party—those must be specified. Reviewer #1: Yes Reviewer #2: Yes ****** 5. Is the manuscript presented in an intelligible fashion and written in standard English? PLOS ONE does not copyedit accepted manuscripts, so the language in submitted articles must be clear, correct, and unambiguous. Any typographical or grammatical errors should be corrected at revision, so please note any specific errors here. Reviewer #1: Yes Reviewer #2: Yes ****** 6. Review Comments to the Author Please use the space provided to explain your answers to the questions above. You may also include additional comments for the author, including concerns about dual publication, research ethics, or publication ethics. (Please upload your review as an attachment if it exceeds 20,000 characters) Reviewer #1: Although the data presented by the authors did not quite meet my expectations, the authors explained why and provided some additional experimental data to support their experimental results. It is hoped that there will be better experimental reagents in the future, otherwise the application of this cell line will be limited. Reviewer #2: The authors have adequately addressed my comments, the manuscript has improved from its previous version. ****** 7. PLOS authors have the option to publish the peer review history of their article (what does this mean?). If published, this will include your full peer review and any attached files. If you choose “no”, your identity will remain anonymous but your review may still be made public. Do you want your identity to be public for this peer review?** For information about this choice, including consent withdrawal, please see our Privacy Policy. Reviewer #1: No Reviewer #2: No https://doi.org/10.1371/journal.pone.0266061.r003
Formally Accepted
24 Mar 2022 Acceptance Letter - Wuqiang Zhu, Editor PONE-D-22-00223R1 Novel cell lines derived from Chinese hamster kidney tissue Dear Dr. Kamihira: I'm pleased to inform you that your manuscript has been deemed suitable for publication in PLOS ONE. Congratulations! Your manuscript is now with our production department. If your institution or institutions have a press office, please let them know about your upcoming paper now to help maximize its impact. If they'll be preparing press materials, please inform our press team within the next 48 hours. Your manuscript will remain under strict press embargo until 2 pm Eastern Time on the date of publication. For more information please contact onepress@plos.org. If we can help with anything else, please email us at plosone@plos.org. Thank you for submitting your work to PLOS ONE and supporting open access. Kind regards, PLOS ONE Editorial Office Staff on behalf of Dr. Wuqiang Zhu Academic Editor PLOS ONE https://doi.org/10.1371/journal.pone.0266061.r004

Open letter on the publication of peer review reports

PLOS recognizes the benefits of transparency in the peer review process. Therefore, we enable the publication of all of the content of peer review and author responses alongside final, published articles. Reviewers remain anonymous, unless they choose to reveal their names.

We encourage other journals to join us in this initiative. We hope that our action inspires the community, including researchers, research funders, and research institutions, to recognize the benefits of published peer review reports for all parts of the research system.

Learn more at ASAPbio .