Mitochondrial metabolism sustains CD8+ T cell migration for an efficient infiltration into solid tumors

The ability of CD8+ T cells to infiltrate solid tumors and reach cancer cells is associated with improved patient survival and responses to immunotherapy. Thus, identifying the factors controlling T cell migration in tumors is critical, so that strategies to intervene on these targets can be developed. Although interstitial motility is a highly energy-demanding process, the metabolic requirements of CD8+ T cells migrating in a 3D environment remain unclear. Here, we demonstrate that the tricarboxylic acid (TCA) cycle is the main metabolic pathway sustaining human CD8+ T cell motility in 3D collagen gels and tumor slices while glycolysis plays a more minor role. Using pharmacological and genetic approaches, we report that CD8+ T cell migration depends on the mitochondrial oxidation of glucose and glutamine, but not fatty acids, and both ATP and ROS produced by mitochondria are required for T cells to migrate. Pharmacological interventions to increase mitochondrial activity improve CD8+ T cell intratumoral migration and CAR T cell recruitment into tumor islets leading to better control of tumor growth in human xenograft models. Our study highlights the rationale of targeting mitochondrial metabolism to enhance the migration and antitumor efficacy of CAR T cells in treating solid tumors.

EBV-Positive Inflammatory Follicular Dendritic Cell Sarcoma of the Spleen: Report of an Aggressive Form With Molecular Characterization

EBV-positive inflammatory follicular dendritic cell sarcoma (EBV+ inflammatory FDCS) is a rare neoplasm almost exclusively located in the spleen or liver. It is characterized by a proliferation of EBV-positive spindle-shaped cells bearing follicular dendritic cell markers, associated with an abundant lymphoplasmacytic infiltrate. EBV+ inflammatory FDCS is often asymptomatic or responsible for mild symptoms. It usually displays an indolent course and its prognosis is excellent after tumor removal, although relapsing and metastatic forms exist. Herein, we describe an aggressive form of splenic EBV+ inflammatory FDCS in a 79-year-old woman presenting with abdominal pain, deterioration of general health status, major inflammatory syndrome, and symptomatic hypercalcemia. A splenectomy was performed leading to a rapid improvement in her clinical condition and normalization of laboratory abnormalities. Unfortunately, her symptoms and laboratory abnormalities reappeared 4 months later. Computed tomography showed a mass in the splenectomy site and multiple liver and peritoneal nodules. Further analyses were performed on tumor tissue and showed positive phospho-ERK staining of tumoral cells indicating activation of MAPK pathway. Inactivating mutations were found on CDKN2A and NF1 genes. Subsequently, the patient's condition deteriorated rapidly. Since interleukin-6 levels were dramatically increased, tocilizumab was used but only had a transient effect on the patient's symptoms and inflammatory syndrome. Antitumor agent gemcitabine was initiated but her clinical condition continued to deteriorate and the patient died 2 weeks later. The management of aggressive forms of EBV+ inflammatory FDCS remains challenging. However, since these tumors seem to display genetic alterations, better characterization could lead to molecular targeted therapies.

Impact of sarcopenia indexes on survival and severe immune acute toxicity in metastatic non-small cell lung cancer patients treated with PD-1 immune checkpoint inhibitors

BACKGROUND & AIMS

Sarcopenia has long been associated with higher toxicity induced by anti-cancer treatments and shorter survival in patients with solid tumors. The creatinine-to-cystatin ratio (CC ratio, serum creatinine/cystatin C × 100) and the sarcopenia index (SI, serum creatinine × cystatin C (CysC)-based glomerular filtration rate (eGFR_CysC)) are have been reported to be correlated with skeletal muscle mass. The aim of this study is to assess primarily whether the CC ratio and the SI could predict mortality in metastatic non-small cell lung cancer (NSCLC) patients treated with PD-1 inhibitors, and secondarily their impact on severe immune-related adverse effects (irAEs).

METHODS

From the prospective CERTIM cohort, we analyzed retrospectively stage IV NSCLC patients, who received PD-1 inhibitors between June 2015 and November 2020 in Cochin Hospital (Paris, France). We assessed sarcopenia measuring skeletal muscle area (SMA) by computed tomography and handgrip strength (HGS) by a hand dynamometer.

RESULTS

In total, 200 patients were analyzed. The CC ratio and the IS were significantly correlated with SMA and HGS: r_CC/SMA = 0.360, r_SI/SMA = 0.407, r_CC/HGS = 0.331, r_SI/HGS = 0.370. In multivariate analysis of overall survival, a lower CC ratio (HR 1.73, P = 0.033) and a lower SI (HR 1.89, P = 0.019) were independent predictors of poor prognosis. In univariate analysis of severe irAEs, CC ratio (OR 1.01, P = 0.628) and SI (OR 0.99, P = 0.595) were not associated with a higher risk of severe irAEs.

CONCLUSIONS

In metastatic NSCLC patients treated with PD-1 inhibitors, a lower CC ratio and a lower SI are independent predictors of mortality. However, they are not associated with severe irAEs.

Abstract 1693: Prediction of the efficacy of nivolumab using resting energy expenditure in metastatic non-small cell lung cancer (mNSCLC) patients

Background: Immune evasion and deregulation of energy metabolism play a pivotal role in cancer progression. Immunosuppression in the tumor microenvironment can be based on the mutual metabolic requirements of immune and tumor cells. We evaluated the value of resting energy expenditure (REE) as a predictor of outcome, in mNSCLC patients under Nivolumab, an immune checkpoint inhibitor.

Methods: We studied the relation between REE, clinical and biological markers of cachexia and inflammation, and response to Nivolumab in 82 consecutive mNSCLC patients. Efficacy was assessed every 2 months according to Response Evaluation Criteria in Solid Tumors (RECIST) criteria. REE was measured using indirect calorimetry, before the initiation of Nivolumab. According to their REE and with the use of Boothby's standard, patients were categorized as hypermetabolic, normometabolic and hypometabolic. Body mass index (BMI), performance status (PS), C-reactive protein (CRP), albumin, Neutrophil Lymphocyte R Ratio (NLR) and PD-L1 tumor expression were also recorded.

Results: Patients characteristics were: 62% males, median age of 65 years (range 37-78), 61% PS 0-1, median BMI of 24 kg.m-² (range 17-39), 78% nonsquamous NSCLC. The analysis of REE was available for 69 out of 82 consecutive pts: 37.7% were hypermetabolic, 47.8% were normometabolic, and 14.5% were hypometabolic. In univariate analysis, hypometabolism was a strong predictive marker of disease progression (Table 1), with positive and negative predictive values of 0.80 and 0.52 respectively. In multivariate analysis, independent parameters associated with disease progression were baseline hypometabolism (vs normometabolism: OR 1.77 [1.31-2.39] p= 0.0004) and albumin (per 1pt increase: OR 0.96 [0.94-0.99] p= 0.005).

Conclusion: Rest energy expenditure assessed by calorimetry appears as a biomarker of nivolumab clinical activity independently of PD1/PDL1 status.

Table 1Disease control (best response) n (%)<85% calculated REE n=10 (14.5%) Hypometabolic85-115% calculated REE n=33 (47.8%) Normometabolic>115% calculated REE n=26 (37.7%) Hypermetabolicunivariate OR (Hypometabolic vs normometabolic)pProgression8 (80%)11 (33%)17 (65%)8 [1.4-44.2]0.0007Disease control rate2 (20%)22 (67%)9 (35%)

Citation Format: Claire Gervais, Pascaline Boudou-Rouquette, Anne Jouinot, Jeanne Chapron, Jennifer Arrondeau, Marco Alifano, Frédérique Giraud, Olivier Huillard, Jérôme Alexandre, Clara Vazeille, Jean-Philippe Durand, Karen Leroy, Marie-Pierre Revel, Jean-Pascal de Bandt, Luc Cynober, Diane Damotte, Audrey Lupo-Mansuet, François Goldwasser. Prediction of the efficacy of nivolumab using resting energy expenditure in metastatic non-small cell lung cancer (mNSCLC) patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1693.