Large B-cell lymphoma imprints a dysfunctional immune phenotype that persists years after treatment.

Immunotherapy has become standard of care in the treatment of diffuse large B-cell lymphoma (DLBCL). Changes in immunophenotypes observed at first diagnosis predict therapy outcome but little is known about the resolution of these alterations in remission. Comprehensive characterization of immune changes from fresh, peripheral whole blood revealed a functionally relevant increase of myeloid-derived suppressor cells, reduced naïve T-cells, and an increase of activated and terminally differentiated T-cells before treatment which aggravated after therapy. Suggesting causal relation, injection of lymphoma in mice induced similar changes in the murine T cells. Distinct immune imprints were found in breast cancer and AML survivors. Identified alterations persisted beyond five years of ongoing complete remission and in DLBCL correlated with increased pro-inflammatory markers such as IL-6, B2M, or sCD14. The chronic inflammation was associated with functionally blunted T-cell immunity against SARS-CoV-2-specific peptides and reduced responses correlated with reduced Tn-cells. Persisting inflammation was confirmed by deep sequencing and by cytokine profiles, together pointing towards a compensatory activation of innate immunity. The persisting, lymphoma-induced immune alterations in remission may explain long-term complications, have implications for vaccine strategies, and are likely relevant for immunotherapies.