Metabolic reprogramming of antitumor T cells for optimal adoptive immunotherapy

2020 Fiscal Year Research-status Report

• Project/Area Number: 20K22793
• Research Institution: Aichi Cancer Center Research Institute
• Principal Investigator: 呉 智聞 愛知県がんセンター(研究所), 腫瘍免疫応答研究分野, リサーチレジデント (80883983)
• Project Period (FY): 2020-09-11 – 2022-03-31
• Keywords: CAR-T / metabolism / immunotherapy

Outline of Annual Research Achievements

We have explored metabolic targets associated with T cell functions and identified that CAR-T cells treated with dorsomorphin (DM), a selective AMPK inhibitor, significantly maintained a young memory phenotype and cytokine polyfunctionality in a dose-dependent manner without affecting proliferative capacity compared with untreated group.
DM-treated T cells showed reduced levels of phosphor-Akt as well as phosphor-AMPK. When DM-treated T cells were infused into NSG mice, they showed enhanced persistence compared with the control T cells.
In addition to pharmacologic inhibition, we also tested the effect of genetic knockout (K.O.) and dominant-negative (DN) mutant modification of AMPK subunit (PRKAA1) in CAR-T cells. The result is consistent with DM-treated group in vitro.

Current Status of Research Progress

3: Progress in research has been slightly delayed.

Reason

The AMPK pathway is considered to redirect cellular metabolism towards increased catabolism and decreased anabolism through negatively regulating one of the main anabolic pathway mTOR/Akt. Unexpectedly, dorsomorphin-treated T cells also showed reduced levels of phosphor-Akt as well as phosphor-AMPK, suggesting that AMPK inhibition paradoxically suppresses Akt signaling, which may result in supporting memory T cell formation.
We are working on the mechanism according to the phenotype we observed and try to figure it out to catch up the procedure as planned.

Strategy for Future Research Activity

Molecular mechanism on how Dorsomorphin affects memory T cell differentiation will be investigated. We will perform RNA-sequencing analysis to elucidate how the AMPK inhibition affects transcriptional profiles of CAR-T cells.
We will analyze metabolic changes including glycolysis, oxygen consumption, fatty acid oxidation and glutaminolysis in the AMPK-inhibited T cells compared with control T cells. The effect of PRKAA1-KO and DN-PRKAA1 in CAR-T cells will be evaluated in vivo as well.
The persistence and differentiation of CAR-T cells with various treatment will be analyzed.
Next, we will test antitumor efficacy of dorsomorphin-treated CAR-T cells in the solid tumor model. Mice will be regularly injected with dorsomorphin or vehicle and analyzed for tumor progression.

Causes of Carryover

It is necessary to be used for next year because immunodeficient mice (NSG mice) will be purchased to perform in vivo functional analysis of T cells. Meanwhile we will analyze gene expression profiles of T cells by RNA sequencing.