To test a drug that works on humans,
in a mouse
Anti-PD1 binds human PD-1 only. It does not bind the mouse receptor. Give it to an ordinary mouse and nothing happens.
The answer is to build a human immune system inside the mouse. Over these 20 lessons you meet the three genes that erase mouse immunity, the Sirpα that keeps human cells alive, the conditioning dose and the CD34⁺ injection, the %hCD45 twelve weeks later, and the clock that xenogeneic GvHD starts. Python runs right inside this page. There is nothing to install.
How you'll learn
Three genes that erase mouse immunity, and one Sirpα that keeps human cells alive. Instead of memorising strain names you see what has to be missing, and why.
Raise the conditioning dose and engraftment goes up — and so does mortality. hu-PBL is fast but over in four weeks. You turn each trade-off yourself on a slider.
Change the donor and the conclusion changes. Quietly drop the mice that died of GvHD and the survival curve lies. You walk into those traps by hand.
Every lesson has a laboratory widget — picking the strain, the conditioning dose, the engraftment gate, the GvHD score, the anti-PD1 schedule, all turned by you.