Replies to post #483 on Genocea Biosciences Inc (GNCAQ)

[jondoeuk]

Speaking of double positive cell populations, one group has published data that show tumour-reactive CD8+ T-cells are CD39/CD103 double positive https://www.nature.com/articles/s41467-018-05072-0

These cells have been found in many solid tumours, including melanoma, lung, renal, breast, head and neck cancer, colon, ovarian, and pancreatic. Some types have a much higher frequency (e.g., melanoma and lung, 30-80%), while others don't (e.g., pancreatic and colorectal liver mets, 2-15%). These TIL have a resident memory phenotype and are highly enriched within the tumour site(s) when compared to peripheral blood.

They are enriched for cells reactive to neoantigens and/or viral associated tumour antigens (HPV+ types). They express high levels of exhaustion markers (e.g., PD-1, CTLA-4, TIM-3 and LAG-3), but also are enriched for activation and proliferation markers (e.g., 4-1BB, Granzyme B and Ki-67).

One company can sort and culture as few as 2-10,000 TIL and grow them to billions in a five-week span. They plan to perform a PhI trial this year.