Fitness and immune-escape within germinal centers shape premalignant evolution toward lymphoma

09 Jul 20264 min read0 viewsVerified Feed

GIST (Key Takeaways)

Germinal centers (GCs) support physiological B-cell mutagenesis and are considered lymphoma-permissive; nevertheless, lymphoma development is uncommon. Human in situ follicular neoplasia (ISFN) captures this paradox: premalignant B-cells can persist within GCs for prolonged periods without progressing to overt lymphoma. We found that human ISFN, but not normal GCs, are infiltrated by CD8 T-cells, suggesting that premalignant GC B-cells are locally immune-surveilled.
Using mouse models that separate early premalignant fitness from lymphoma-associated evolution, we show that fitness-enhanced premalignant GC B-cells expand transiently but are selectively eliminated by infiltrating cytotoxic CD8 T-cells, while normal GC B-cells are spared. By contrast, evolved premalignant GC B-cells retain their fitness but disable productive CD8 T-cell cytotoxic differentiation, allowing persistence and lymphoma-like transcriptional and genomic evolution. These findings establish GCs as active immune-surveillance sites and show that progression from premalignancy to lymphoma requires both enhanced GC fitness and escape from local immune control.
Key findingsGCs undergo active immune-surveillance to detect premalignant B-cells. Premalignant GC B-cells trigger cytotoxic CD8 T-cell responses. Lymphoma-associated evolution enables immune-escape within GCs.
Fitness and immune-escape drive evolution from premalignancy to lymphoma.