Superior antitumor immunotherapy efficacy of kynureninase modified CAR-T cells through targeting kynurenine metabolism

Abstract

Accumulated oncometabolites in the tumor microenvironment (TME) suppresses the metabolism, expansion, and function of T cells. Immunosuppressive TME also impeded Chimeric Antigen Receptor (CAR)-T cells mediated cytotoxicity since CAR-T cells had to adapt the in vivo metabolic characteristics with high levels of oncometabolites. We screened oncometabolites for the inhibition of glucose uptake in CD8 + T cells and found Kynurenine (Kyn) showed the strongest inhibiting effect on glucose uptake. In vitro experiments showed that 120 μM Kyn treatment in CD8 + T cells resulted in inhibiting the expansion of CD8 + T cells, decreasing the production of granzyme B and interferon-γ. CAR-T cells mediated cytotoxicity was also impaired by the high Kyn treatment from killing assay. We then explored the anti-tumor effect of Kynureninase (KYNU) modified CAR-T cells through catabolism o oncometabolites Kyn. KYNU over-expression (OE) CAR-T cells showed a superior killing effect against cancer cells even in the immunosuppressive TME with high Kyn levels. In vivo experiments confirmed KYNU-OE CAR-T cells showed an excellent anti-tumor effect in a TME with high Kyn levels since it improved the survival of mice bearing NALM6 cancer cells and NALM6-IDO1 cancer cells. The KYNU-modified CAR-T cells displayed distinct phenotypes related to the expansion, function, and memory differentiation status of CAR-T cells. This study explores an immunotherapy strategy for patients with alterations in Kyn metabolism. KYNU-OE CAR-T cells take advantage of Kyn catabolism to improve anti-tumor activity in the metabolic immunosuppressive TME with high Kyn.

Engineering CREB‐activated promoters for adenosine‐induced gene expression

“…Strategies that incorporate other heterologous response elements (e.g., dioxin responsive element or hypoxic responsive element) that allow for response to other mechanisms of immune suppression tumors may also be promising routes to expand the function and utility of these synthetic promoters. [55][56][57] In sum, we engineered effective ADOactivated promoters with high induction strengths that are activated in response to tumoral environmental conditions, as well as put forward considerations for testing ADO-mediated cellular responses in vitro with FBS.…”

Discovering KYNU as a feature gene in hidradenitis suppurativa

“…KYNU is widely expressed in nearly all organs of the body, with particularly elevated levels observed in the liver, urinary bladder, and appendix. 50 KYNU is involved in various inflammatory skin diseases, [51][52][53][54][55] cardiovascular diseases, 56 inflammatory bowel disease, 57,58 and several types of cancers, [59][60][61][62][63] exerting its effects through diverse pathways. While previous studies have indicated abnormalities in tryptophan metabolism within HS lesions, 18 there is currently a scarcity of research confirming the distinctive expression pattern of KYNU specifically in HS.…”

CAR-T Cell Therapy in Hematological Malignancies: Current Opportunities and Challenges

“…Kynurenine (Kyn) is an oncometabolite which exists in various hematopoietic malignancies, such as lymphoma and leukemia, and the enzyme kynurenine catalyzes the degradation of Kyn. Thus, the anti-CD19 CAR-T cells were genetically modified with the enzyme kynurenine gene, and they exhibited the improved antitumor activity against Nalm6-GL cells in the immunosuppressive tumor microenvironment with high Kyn (269). Interestingly, some target antigens are co-expressed on immunosuppressive cells in tumor microenvironment, so targeting these antigens can simultaneously eliminate malignant cells and immunosuppressive cells.…”