Immune Immune Booster 20: Lipid GPS for T cells with Susan Schwab
Dec 16, 2025
In this engaging discussion, Professor Susan Schwab from NYU Grossman School of Medicine shares her journey from environmental advocacy to pioneering research in immunology. She dives into how sphingosine-1-phosphate (S1P) directs T cell movement, deciding when they should leave tissues. Susan also reveals intriguing findings about S1P's role in leukemia migration and highlights the use of optogenetic tools to track T cell behavior. Plus, she shares a hilarious travel tale involving flying cockroaches!
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Caramel Color Led To A Key Discovery
- Schwab traced a mysterious lymphopenia from caramel color to vitamin B6 differences between lab diets.
- That led to finding a vitamin B6–dependent enzyme degrades a chemoattractant and tied into S1P regulation.
S1P Gradients Guide T Cell Exit
- Sphingosine 1-phosphate (S1P) forms gradients that tell T cells when they've reached a vessel and should exit tissues.
- High S1P in blood and lymph versus low tissue levels provides a key ‘stay-or-go’ cue for T cells.
T Cells Constantly Decide To Stay Or Go
- T cells repeatedly face 'stay-or-go' decisions across development, activation, and tissue residency.
- Proper timing of exits prevents autoimmunity, enables effective surveillance, and shapes memory versus chronic inflammation.