Expression of Semaphorin4C by Th2-stimulated B cells
Bibliographic record
Abstract
Background Semaphorins are a family of proteins implicated in neurogenesis, angiogenesis and axonal migration. Previous work from our laboratory has shown that Th2stimulated B cells express a unique semaphorin, SEMA4C. Given the roles of other semaphorins, we hypothesized that SEMA4C was expressed on Th2stimulated B cells and might play a role in B cell trafficking and tissue homing therefore being expressed stronger in terminally differentiated B cells, such as memory and plasma cells. Experiment and results B cells were purified from tonsils removed from children undergoing routine tonsillectomy. They were cultured for 24 hours or 7 days at a concentration of 5X10 4 cells/mL in complete medium in the presence of aCD40 with either IFNg, IL-4, IL-21 or both IL-4 and IL-21. RNA was extracted, cDNA was made, and SEMA4C mRNA was amplified by qPCR and compared to the housekeeping gene GAPDH. After 24h culture, SEMA4C mRNA expression was detected only in IL-4stimulated cells but after 7 days, the expression was much stronger in both conditions containing IL-21, and decreased in IL-4-only stimulated cells. B cells were also similarly cultured for 72 hours at a concentration of 0.5X10 6 cells/mL in chamber slides. Slides were stained for SEMA4C with a fluorescent Alexa488 antibody and then visualized using fluorescent microscopy. As expected, stimulation with IL-21 yielded much higher SEMA4C expression than IL-4 alone whereas IFNg did not induce significant staining. Figures 1 and 2. Conclusion SEMA4C is induced in B cells upon Th2 stimulation but increases further upon follicle-like differentiation triggered by IL-21. This data confirms that SEMA4C is specific to terminally-differentiated B cells and supports our hypothesis that it might play a role in B-cell trafficking and homing in peripheral tissue follicles. SEMA4C could therefore be a key player in local allergic inflammation.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| 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 | 0.001 |
| Insufficient payload (model declined to judge) | 0.004 | 0.002 |
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 source (direct Gemma or distilled Codex), 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".