In Vitro Characterization of Influenza A Virus Attachment in the Upper and Lower Respiratory Tracts of Pigs
Bibliographic record
Abstract
The binding of influenza A viruses to epithelial cells in the respiratory tract of mammals is a key step in the infection process. Therefore, direct assessment of virus-host cell interaction using virus histochemistry (VH) will enhance our understanding of the pathogenesis of these new viruses. For this study, the authors selected viruses that represented the 4 main genetic clusters of North American swine H1 (SwH1) viruses, along with A/California/04/2009 H1N1 and a vaccine strain for the positive controls, and the virus label, fluorescein isothiocyanate (FITC), for the negative control. A group of 5 viruses containing a 2-amino acid insertion adjacent to the binding site of the hemagglutinin protein and their presumed ancestral viruses were also examined for changes in binding patterns. Viruses were bound to formalin-fixed paraffin-embedded, 6-week-old (6w) and adult pig tissues. Qualitative VH scores per respiratory zone ranged from + to +++, with bronchioles having the highest and most consistent scores, regardless of animal age. For the 6w bronchioles, a quantitative VH score was calculated using digital images of 5 bronchioles per tissue section using image analysis software. Significant differences in attachment were found among the SwH1 viruses (P < .0001) and among the ancestral and insertion viruses (P < .0001). These results provide new insights on virus binding to porcine respiratory epithelial cells and the usefulness of morphometric scores. The results also highlight limitations of in vitro techniques, including VH for predicting virulence and host range.
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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 | 0.001 | 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".