The position of phosphorylcholine on the lipopolysaccharide of <i>Haemophilus influenzae</i> affects binding and sensitivity to C‐reactive protein‐mediated killing
Bibliographic record
Abstract
The lic1 locus of Haemophilus influenzae controls the incorporation of environmental choline into lipopolysaccharide (LPS) as phosphorylcholine (ChoP) as well as the phase variation of this structure. ChoP is the target of an acute phase reactant in serum, C-reactive protein (CRP), which mediates killing through the activation of complement when bound to the organism. Structural analysis of the oligosaccharide region of the H. influenzae LPS showed that ChoP is linked to different hexose residues on different chain extensions in strains Rd and Eagan. Differences in the molecular environment of ChoP affect the epitope defined by monoclonal antibody 12D9 and were associated with polymorphisms within LicD, a putative diphosphonucleoside choline transferase. Exchanging the licD genes between the two strains with ChoP on different chain extensions was sufficient to switch its position. Allelic variants with ChoP on a hexose on heptose III rather than heptose I were sensitive to CRP-mediated serum bactericidal activity regardless of the genetic background. Differences in CRP-mediated killing correlated with differences in the binding of CRP from human serum to whole bacteria. This suggests that, in addition to the mechanism involving phase variation, the structural rearrangements within the oligosaccharide contribute to evasion of innate and acquired immunity.
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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".