The differential immunological impact of photon vs proton radiation therapy in high grade lymphopenia

This study was a collaboration between several MGH labs (regrettably delayed for some years due to PIs leaving and a global pandemic), investigating the immunological impact of different forms of radiation therapy (xRT) upon the immune system during radiation-induced lymphopenia, given the importance of rationally designing xRT and immune checkpoint blockade combination therapies.

While proton-based xRT had a relatively minor impact on the T cell repertoire despite the profound lymphopenia, photons induced a dramatic loss of diversity driven by CD8 T cell expansions, reminiscent of the my prior HIV study.