Conventional tumor-infiltrating lymphocyte (TIL) therapy for solid tumors relies on high-dose interleukin-2 (IL-2) during expansion and post-infusion, and promotes T-cell exhaustion and toxicity. Herein, we developed a feeder-free, low-dose IL-2 TIL expansion protocol and evaluated whether hydroxychloroquine (HCQ) or programmed cell death protein 1 (PD-1) blockade might enhance therapeutic efficacy and decrease IL-2 dependence.
TILs from multiple solid tumors were expanded ex vivo with decreased-dose IL-2, IL-7, and IL-15 plus CD3/CD28 co-stimulation, without feeder cells. TIL products were assessed via quality control, T-cell phenotypes, and exhaustion markers. Cytotoxic activity was measured in vitro through interferon-gamma (IFN-γ) release and real-time cell analysis (RTCA). HCQ-induced changes in major histocompatibility complex class I (MHC-I) and programmed death-ligand 1 (PD-L1) expression were assessed in tumor cell lines, and RTCA-based cytotoxicity was evaluated using T-cell receptor–engineered T cells (TCR-T cells). The in vivo efficacy of HCQ and PD-1 blockade separately combined with TIL therapy was examined in a colorectal cancer patient-derived xenograft (PDX) model.
The protocol consistently produced viable TILs of favorable quality across tumor types, with variable CD8+ and memory T-cell profiles. Expanded TILs showed effector-to-target (E:T) ratio-dependent tumor cell killing in RTCA and secreted IFN-γ across multiple tumor types. HCQ significantly upregulated MHC-I expression in vitro (P < 0.05) without affecting PD-L1 expression or impairing TIL proliferation, and enhanced early TCR-T–mediated killing. In the PDX model, TIL plus HCQ, compared with TIL, showed less tumor growth and greater MHC-I expression, although these differences were not significant, given the small sample size. TIL plus low-dose PD-1 blockade significantly reduced tumor volume versus the control group (P = 0.002) and maintained higher body weights than the TIL-only and control groups.
The feasibility of a feeder-free, low-dose IL-2 TIL expansion system was demonstrated. PD-1 blockade significantly enhanced antitumor activity and treatment tolerability, thus supporting its promise as an alternative to high-dose IL-2. HCQ demonstrated potential immunomodulatory effects, although its in vivo benefit was minimal. This strategy warrants further clinical evaluation in solid tumors.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |