It may be possible to target cancers that have a viral component, such as Merkel cell carcinoma (MCC), in a whole new way. Researchers at Seattle’s Fred Hutchinson Cancer Research Center and the University of Washington published an article online Jan. 16 in Cancer Immunology Research suggesting ways to improve immune therapy for certain cancers including a virus-associated form of MCC.1
The Seattle researchers conducted an in-depth analysis of the CD8 T cells that respond to a specific part of the Merkel cell polyomavirus. The researchers focused on T cells that target a specific piece of the virus (KLLEIAPNC [KLL]). They found that only about 20% had T cells specific for the KLL region of the virus, suggesting that about 80% of patients with MCC aren’t making T cells that recognize the target.
The investigators performed an analysis on blood and in tumors from 12 patients who had T cells that could recognize KLL. Among these 12 patients, there were 397 unique ways for the T cells to recognize this piece of the virus and only one T cell receptor was shared between 2 patients. The team hopes that these findings will lead to new therapies where T cell receptors can be turned into a therapy for patients who do not have them. The researchers are planning a trial to investigate whether transgenic T cell therapy can reprogram lymphocytes to eliminate tumors in combination with checkpoint inhibition.
1. Miller NJ Church CD, Dong L, et al. Tumor-inﬁltrating Merkel cell polyomavirus-speciﬁc T cells are diverse and associated with improved patient survival. Cancer Immunol Res. 2017 Jan 16. doi: 10.1158/2326-6066.CIR-16-0210 [Epub ahead of print]