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Carmen?

@probablycarmen.bsky.social

42 followers 58 following 18 posts

Doctorate Candidate at the Bottanelli lab? #FUBiochemistry ?

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Carmen? @probablycarmen.bsky.social · 09/07/2025

Woops! .png with no background ruined EVERYTHING. Here is a readable version:

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Carmen? @probablycarmen.bsky.social · 09/07/2025

13. Even when we used a non-signalling CAR mutant, CD45 was still excluded at protrusions. So the enhanced CD45 exclusion is not signalling-dependent.

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Carmen? @probablycarmen.bsky.social · 09/07/2025

12. We observed that exclusion at protrusion contacts happened earlier and more strongly when compared to CD45 exclusion at flat membranes

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Carmen? @probablycarmen.bsky.social · 09/07/2025

11. The answer is the increased of CD45 exclusion at protrusion mediated contacts

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Carmen? @probablycarmen.bsky.social · 09/07/2025

10. Interestingly, Lck doesn’t rearrange at the macroscale. It stays uniformly distributed even during activation, without any specific enrichment in protrusions at any point So what drives the enhanced protrusion CAR activation?

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Carmen? @probablycarmen.bsky.social · 09/07/2025

8. Then comes LAT, clustering downstream of ZAP-70. LAT clusters appear faster and more intensely in protrusions compared to main body membrane regions

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Carmen? @probablycarmen.bsky.social · 09/07/2025

7. The CAR clusters are activated immediately and the increased CAR enrichment in protrusions is accompanied with an increased ZAP-70 recruitment to these structures

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Carmen? @probablycarmen.bsky.social · 09/07/2025

6. The result: CARs enrich faster and stronger in protrusion contacts than flat membranes

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Carmen? @probablycarmen.bsky.social · 09/07/2025

5. In collaboration with Amin from the @ewerslab.bsky.social, we developed an image analysis pipeline to distinguish between protrusions and main body protein rearrangements

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Carmen? @probablycarmen.bsky.social · 09/07/2025

4. The logic works both ways: protrusive structures from the breast cancer cell are also able to push into the T cell and create a contact that accumulates CARs!

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Carmen? @probablycarmen.bsky.social · 09/07/2025

3. But the game changes when T cells meet their targets. First contacts happen via protrusions. Within seconds, CARs cluster specifically at these sites. In here, you can see a Jurkat T cell expressing a HER2-CAR (yellow) and a membrane marker (cyan) contacting a breast cancer cell (magenta).

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Carmen? @probablycarmen.bsky.social · 09/07/2025

2. In resting T cells, none of these signalling proteins were enriched in protrusions...

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Carmen? @probablycarmen.bsky.social · 09/07/2025

We CRISPR-edited Jurkat T cells to tag key signalling proteins Lck, ZAP-70, LAT, and CD45 at their endogenous loci. This means no overexpression or immunolabelling artefacts! Then we used live-cell STED and confocal imaging to track them in 4D

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