Endogenous Retrovirus‐Like Particle‐Deficient CHO Cells Can be Generated by CRISPR or shRNA and Enriched Based on Cell‐Surface Expression of Retroviral Envelope Protein
Bibliographic record
Abstract
Despite evidence that they are not functional or infective, retrovirus-like particles (RVLPs), originating from endogenous proviral sequences in Chinese hamster ovary (CHO) cells, present a safety risk for biotherapeutics manufactured using this cell line due to their resemblance to other mammalian leukemia viruses. Here, we demonstrate that CRISPR- and shRNA-based cell engineering strategies can be used to disrupt RVLP production by targeting the RVLP nucleotide sequences. Additionally, specific antibodies were generated to monitor RVLP protein expression, including RVLP envelope (Env) protein localized on the surface of CHO cells, greatly facilitating selection of RVLP-deficient clones. These modified CHO cells showed reduced RVLP production while maintaining or enhancing the ability to produce recombinant virus-like particles (VLPs), highlighting their potential application in biomanufacturing, especially for complex biologics that are incompatible with standard RVLP mitigation procedures, namely viral inactivation and nanofiltration.
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How this classification was reachedexpand
Full frame distilled prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. Learned from the 10,348 direct Codex labels and 10,348 direct Gemma labels. Candidate is the union of thresholded teacher heads; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels or direct frontier model labels.
Codex and Gemma teacher scores by category
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.000 | 0.000 |
| Insufficient payload (model declined to judge) | 0.000 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one teacher head, not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".