Abstract: The present invention includes methods of detecting follicular regulatory T cells (TFR) comprising: obtaining a biological sample from a subject and detecting whether TFR are increased in the tumor sample by contacting the biological sample with antibodies that detect CD3+CD4+ FOXP3+BCL6+ T cells CD3+CD4+CXCR5+GITR+ T cells, or both, when compared to a healthy subject, and detecting the increase of TFR in the tumor sample. The present invention also includes combination therapy that depletes follicular regulatory T cells (TFR) with minimal effect on regulatory T cells (TREGS) to prevent or reduce immune related adverse effects (irAEs).

Abstract: This disclosure provides methods of treating cancer or eliciting an anti-tumor response in a subject by administering an effective amount of a population of T-cells that exhibits higher or lower than baseline expression of one or more genes. In other aspects, methods are provided to diagnose cancer and determine prognosis of cancer patients. Also provided are methods to identify the antigens or antigen receptors associated with the isolated and/or purified cell populations that elicit a more positive prognosis.