Sheffield continues to surprise -I was expecting rain and steel 🥲

..and the same day we get a definition of what a *good* theory is by @robinsall.bsky.social back here on the island 😅 @sheffielduni.bsky.social

here's a plot showing the increase in the number of persons disappeared by ICE (data as posted by @msbr89.bsky.social):

AND: you can easily play around with the system using VisualPDE developed by @blindmath.bsky.social!! 😍

👉 shorturl.at/kfH4I

Turns out, mechanical nonreciprocity only affects migration dynamics when consumer cells are weakly chemotactic: For sufficiently chemotactic consumers, biochemical non-reciprocity dominates over mechanical forces!

Importantly, after fitting our model with experimental data, we found that DC-T cell migration sits close to the optimal regime (🌟), where both co-migration and colocalization are maximized:

Moreover, the spatial profiles of the cell populations matched the theoretical predictions:

T cells (sensors) showed a concentration peak ahead of DCs (consumers), despite being unable to migrate alone -purely driven by DC-generated gradients!

Strikingly, as predicted by the theory:

🔹DCs (consumers) and T cells (sensors) migrated as coupled travelling waves 🌊
🔹T cells stayed at a conserved distance ahead of DCs!

To test these predictions, we teamed up with the Sixt Lab (ISTA) to design a minimal in vitro experiment:

Dendritic cells (DCs), which shape the gradient, and T cells, acting as sensors, migrated in 1D channels, with cells continuously entering from a reservoir:

🟢When sensor cells become more chemotactic than consumers, they can migrate ahead as a spatially localized “pulse”..

..but the sensor-consumer separation is bounded, as sensors will eventually reach the flat region of the attractant profile!

We find that the chemotactic ability of the sensors controls a sharp transition:

🔴If sensors aren’t chemotactic enough, they can’t follow the gradients generated by consumers and fall behind, leading to an uncoupled migration dynamics.

Inspired by our recent finding that some immune cells can’t self-generate chemical gradients (science.org/doi/10.1126/...), but can "surf" on gradients generated by other cell types, we model:

(i) Consumers: sensing & degrading chemoattractants,
(ii) Sensors: following gradients.

Self-generated gradients guide collective cell movement -but often different cell types must move together, e.g. in immune response.

We develop a theory of self-generated chemotaxis in mixed populations -are there optimal principles for this cooperation?🤔
www.biorxiv.org/content/10.1...

We're based in the School of Mathematical & Physical Sciences @sheffielduni.bsky.social -right next to the amazing peak district! 😍

📣 I’m looking for PhD students to work at the intersection of theoretical physics & biology -topics range from active cell mechanics to collective cell migration & tissue patterning!

Feel free to reach out for more info (DM/email)!

Please repost / share 🙂