Journal: Cell Reports Medicine

Article Title: Targeting severe acidity for tumor-activatable Interleukin-2 therapy

doi: 10.1016/j.xcrm.2025.102572

Figure Lengend Snippet: Chemical composition and pH-responsive behavior of UPS/IL-2-Fc NP (A) Schematic illustrating IL-2-Fc activity control via pH-threshold-dependent encapsulation and release. (B) Chemical structure of UPS polymers used to formulate pH-activatable IL-2-Fc nanoparticles. (C–E) pH-dependent characterization of three UPS/IL-2-Fc formulations: nanoparticle size (C), IL-2-Fc release by ELISA (D), and IL-2 activity in HEK-Blue IL-2 reporter cells (E) ( n = 3). (F) Encapsulation stability of IL-2-Fc in different UPS formulations incubated in PBS, cell culture medium, and mouse plasma at 37°C ( n = 3). (G and H) In vivo evaluation of antitumor efficacy and cytokine release in MC-38 tumor-bearing mice treated with various UPS/IL-2-Fc NPs or unencapsulated IL-2-Fc (0.75 mg/kg, n = 5). Data in (C–G) are presented as mean ± SEM. Heatmap in (H) generated from Z score normalization by column. See also .

Article Snippet: HEK-BlueTM IL-2 Cells , Invivogen , hkb-il2.

Techniques: Activity Assay, Control, Encapsulation, Enzyme-linked Immunosorbent Assay, Incubation, Cell Culture, Clinical Proteomics, In Vivo, Generated

Journal: Cell Reports Medicine

Article Title: Targeting severe acidity for tumor-activatable Interleukin-2 therapy

doi: 10.1016/j.xcrm.2025.102572

Figure Lengend Snippet: pH-responsive blocking and restoration of IL-2 receptor binding by UPS 5.3 (A) Schematic of the experimental design to assess the intrinsic interaction between UPS 5.3 micelles and proteins. (B) FPLC chromatograms showing individual proteins or UPS 5.3 /protein mixtures. (C) Molecular docking model of the DBA dimer (blue) with IL-2, highlighting predicted interaction sites. (D–F) Biolayer interferometry analysis of IL-2-Fc binding to IL-2Rα, IL-2Rβ, and IL-2Rγ, with and without UPS 5.3 NP encapsulation. (G) Schematic illustrating ex vivo assessment of IL-2-Fc binding to immune cells from various organs. (H) Quantification of IL-2-Fc binding to lymphocytes isolated from liver, lung, spleen, and tumor ( n = 5). Data are presented as mean ± SEM. See also and .

Article Snippet: HEK-BlueTM IL-2 Cells , Invivogen , hkb-il2.

Techniques: Blocking Assay, Binding Assay, Encapsulation, Ex Vivo, Isolation

Journal: Cell Reports Medicine

Article Title: Targeting severe acidity for tumor-activatable Interleukin-2 therapy

doi: 10.1016/j.xcrm.2025.102572

Figure Lengend Snippet: Tumor-specific release of IL-2-Fc by UPS 5.3 /IL-2-Fc NP (A) Schematic illustrating measurement of free and total IL-2-Fc levels and the concept of tumor-specific activation. (B) Pharmacokinetic analysis of free and total IL-2-Fc following intravenous administration of UPS 5.3 /IL-2-Fc NP or unencapsulated IL-2-Fc alone ( n = 5). (C) AUC comparison of free and total IL-2-Fc concentrations ( n = 5). (D) PET/computed tomography imaging and quantification in MC-38 tumor-bearing mice 24 h after intravenous injection of 64 Cu-labeled IL-2-Fc or UPS 5.3 /IL-2-Fc NP ( n = 3). (E) Schematic depicting the FRET-based design for assessing IL-2-Fc encapsulation status in vivo . (F) FRET-based analysis of IL-2-Fc encapsulation and release in the spleen, lung, liver, and tumor following systemic administration. Scale bar, 50 μm. Data in (B–D) are shown as mean ± SEM. See also and .

Article Snippet: HEK-BlueTM IL-2 Cells , Invivogen , hkb-il2.

Techniques: Activation Assay, Comparison, Computed Tomography, Imaging, Injection, Labeling, Encapsulation, In Vivo

Journal: Cell Reports Medicine

Article Title: Targeting severe acidity for tumor-activatable Interleukin-2 therapy

doi: 10.1016/j.xcrm.2025.102572

Figure Lengend Snippet: UPS 5.3 /IL-2-Fc NP binds cytotoxic immune cells in tumors and elicits strong antitumor responses (A) Schematic illustrating tumor-specific activation of UPS 5.3 /IL-2-Fc NP in response to severe acidity, promoting cytotoxic immune cell stimulation. (B) Treatment schedule for in vivo evaluation of NK and CD8 + T cell binding and activation. (C) Binding and activation of CD8 + T cells and NK cells by UPS 5.3 /IL-2-Fc NP (red) in MC-38 tumors, showing comparable effects to unencapsulated IL-2-Fc (blue, n = 5). (D) Dose-dependent antitumor efficacy of UPS 5.3 /IL-2-Fc NP in the MC-38 tumor model (n = 7–8). (E) Anti-tumor effect in 4T1 orthotopic tumors with starting size >400 mm 3 . UPS 5.3 /IL-2-Fc NP was administered at 2.25 mg/kg for three doses ( n = 6). (F) Combination therapy in the B16F10 model using UPS 5.3 /IL-2-Fc with either anti-PD-1 or PolySTING. UPS 5.3 /IL-2-Fc NP was administered at 2.25 mg/kg, twice (n = 5–7). Data are shown as mean ± SEM. ∗∗ p < 0.01, ∗∗∗ p < 0.001, ∗∗∗∗ p < 0.0001. See also and .

Article Snippet: HEK-BlueTM IL-2 Cells , Invivogen , hkb-il2.

Techniques: Activation Assay, Cell Stimulation, In Vivo, Binding Assay

Journal: Cell Reports Medicine

Article Title: Targeting severe acidity for tumor-activatable Interleukin-2 therapy

doi: 10.1016/j.xcrm.2025.102572

Figure Lengend Snippet: UPS 5.3 encapsulation blocks IL-2-Fc binding to NK cells in normal tissues, reducing systemic toxicity (A) Treatment regimen and assessment of cell and receptor dependency in IL-2-Fc-induced vascular leak syndrome (VLS). (B) Schematic illustrating UPS 5.3 -mediated inhibition of NK cell activation by IL-2-Fc in normal tissues. (C) Treatment schedule for in vivo evaluation of NK cell binding and activation in major organs. (D) Comparison of IL-2-Fc binding to NK cells and NK cell counts in the spleen, liver, and lung from UPS 5.3 -IL-2-Fc NP (red) and unencapsulated IL-2-Fc (blue). (n = 5–7). (E–G) Improved safety profile of UPS 5.3 /IL-2-Fc NP in C57BL/6 mice, demonstrated by stable body weight (E, n = 5), >100-fold reduction in systemic IFN-γ (F, n = 5), and absence of lung edema (G, n = 3). n = 3 for (A); n = 5 for (D–G). Data are presented as mean ± SEM. ∗∗∗∗ p < 0.0001. See also .

Article Snippet: HEK-BlueTM IL-2 Cells , Invivogen , hkb-il2.

Techniques: Encapsulation, Binding Assay, Inhibition, Activation Assay, In Vivo, Comparison

Journal: Cell Reports Medicine

Article Title: Targeting severe acidity for tumor-activatable Interleukin-2 therapy

doi: 10.1016/j.xcrm.2025.102572

Figure Lengend Snippet: UPS 5.3 NP encapsulation of IL-2-Fc leverages macrophage clearance to reduce systemic toxicity (A) Treatment regimen and histological analysis showing differential IL-2-Fc distribution in the spleen following nanoparticle or free IL-2-Fc administration. W, white pulp; R, red pulp. Scale bars, 100 μm. (B) Body weight changes in C57BL/6 mice treated with IL-2-Fc or UPS 5.3 /IL-2-Fc NP, with or without macrophage depletion using anti-CSF1R ( n = 3). IL-2-Fc dose: 0.75 mg/kg per injection. (C) PBMC-engrafted humanized mice treated with different IL-2-Fc formulations ( n = 5). (D) CD34 + cell-engrafted humanized mice treated with different IL-2-Fc formulations ( n = 5). IL-2-Fc dose for (C and D): 2.25 mg/kg per injection. (E) Circulating cytokine profiles measured in both humanized mouse models post-treatment ( n = 3). Data are presented as mean ± SEM. ∗ p < 0.05, ∗∗ p < 0.01. See also .

Article Snippet: HEK-BlueTM IL-2 Cells , Invivogen , hkb-il2.

Techniques: Encapsulation, Injection