A recent paper published in the journal Nature earlier this year shed some light on why some patients with soft-tissue sarcoma survived longer than others. The researchers expected that it came down to which patients had the most T cells, an immune cell known to contribute to the success of immunotherapy. However, after studying the gene expression of 608 soft-tissue sarcoma tumours, the researchers discovered that the patients with the best outcome had more B cells located within specialised immune-cell clusters, called tertiary lymphoid structures, found at the site of the tumour. These patients so had a high response rate to pembrolizumab, a PD-1 checkpoint inhibitor, in a phase 2 clinical trial.
“Usually in this field most people are focusing on T cells because they’re the immune cells that are mostly responsible for targeting and killing tumour cells,” said Dr Petitprez, who conducted the research at the French National Institute of Health and Medical Research and the French League Against Cancer in Paris. “But our work is important because we showed that B cells contribute to immune checkpoint blockade response. This could be a good tool to guide therapeutic decisions so patients get treatment that’s most likely to be effective for their particular cancer.”
Dr Petitprez’s work is one of three papers published earlier this year in Nature that suggest that B cells have a role in boosting the immune response to several kinds of cancer, including melanoma and renal cell carcinoma (RCC). Although the exact mechanism of action is still unknown, the ability of B cells to generate antibodies suggests they boost the action of T cells, and play a dynamic role in the immune system.