il 21 concentration  (Proteintech)

Journal: Acta Pharmaceutica Sinica. B

Article Title: Attenuated Salmonella secreting interleukin-21 activates T-cells and induces anti-tumor effects

doi: 10.1016/j.apsb.2025.09.025

Figure Lengend Snippet: Construction and characterization of IL-21-secreting Salmonella . (A) Plasmid map designed for the secretion of FlgM-tagged IL-21. (B) After overnight culturing of the Salmonella strain secreting IL-21, 0.2% l -arabinose was added to induce IL-21 expression. Whole cells, cell lysates, and supernatants were collected, and Western blot analysis was performed using anti-His and anti-IL-21 antibodies, respectively. (C) IL-21 secretion was confirmed by ELISA ( n = 5). (D) Growth of the strain secreting IL-21 was compared between induced (0.2% l -arabinose) and non-induced groups by measuring the OD at 600 nm. (E) Western blot analysis using anti-His was conducted to track the secretion of IL-21 over time following induction with 0.2% l -arabinose. (F) Motility assays were performed to examine the motility of the IL-21-secreting strain under 0.2% l -arabinose. The experiments were repeated at least three times, and representative data are shown. Scale bar = 5 mm. Significance is indicated as ∗∗∗∗ P < 0.0001. Data are presented as mean ± SEM.

Article Snippet: After collecting all supernatant samples, the IL-21 concentration was measured using a mouse IL-21 ELISA Kit (KE10012, Proteintech, Rosemont, IL, USA).

Techniques: Plasmid Preparation, Expressing, Western Blot, Enzyme-linked Immunosorbent Assay

Journal: Acta Pharmaceutica Sinica. B

Article Title: Attenuated Salmonella secreting interleukin-21 activates T-cells and induces anti-tumor effects

doi: 10.1016/j.apsb.2025.09.025

Figure Lengend Snippet: Antitumor efficacy of IL-21-secreting Salmonella in tumor-bearing mice. (A) Treatment schedule for cancer therapy using IL-21-secreting Salmonella . CT26 cells (5 × 10 5 ) were subcutaneously injected into the right flank of BALB/c mice. When the tumor size reached approximately 100 mm 3 , Salmonella (2 × 10 7 CFU) was administered intravenously, and from Day 3 post-injection, l -arabinose (80 mg/mouse) was administered intraperitoneally. IL-21(−), without l -arabinose; IL-21(+), with l -arabinose. (B) Representative images of tumor-bearing mice. (C) Tumor volume at 2-day intervals. (D) Body weight changes in each treatment group. (E) Survival curves for each treatment group (data from B–E; n = 7). (F) TUNEL analysis of tumors from each treatment group. (G) Ki-67 expression in tumors from each treatment group. bar = 50 μm. Image quantification data are presented in (H, I) (data from F–I; n = 3). Significance is indicated as ∗ P < 0.05, ∗∗ P < 0.01, ∗∗∗ P < 0.001. Data are presented as the mean ± SEM.

Article Snippet: After collecting all supernatant samples, the IL-21 concentration was measured using a mouse IL-21 ELISA Kit (KE10012, Proteintech, Rosemont, IL, USA).

Techniques: Injection, TUNEL Assay, Expressing

Journal: Acta Pharmaceutica Sinica. B

Article Title: Attenuated Salmonella secreting interleukin-21 activates T-cells and induces anti-tumor effects

doi: 10.1016/j.apsb.2025.09.025

Figure Lengend Snippet: IL-21-secreting Salmonella promotes T cell infiltration and antitumor activity. (A) Experimental scheme in tumor-bearing mice: Immune cells were analyzed in tumor tissues on Day 7. (B) Anti-IL-21 was detected in the tumor tissues using ELISA. (C) In tumor tissues, anti-IL-21 was confirmed through IHC. Scale bar = 50 μm. (D) Image quantification data (data from B–D; n = 3). (E–G) Flow cytometry analysis showed that CD4 + and CD8 + T cells were activated by IL-21 in mouse tumor tissues (data from E–G; n = 3). Significance is indicated as ∗ P < 0.05, ∗∗ P < 0.01, ∗∗∗ P < 0.001. Data are presented as the mean ± SEM.

Article Snippet: After collecting all supernatant samples, the IL-21 concentration was measured using a mouse IL-21 ELISA Kit (KE10012, Proteintech, Rosemont, IL, USA).

Techniques: Activity Assay, Enzyme-linked Immunosorbent Assay, Flow Cytometry

Journal: Acta Pharmaceutica Sinica. B

Article Title: Attenuated Salmonella secreting interleukin-21 activates T-cells and induces anti-tumor effects

doi: 10.1016/j.apsb.2025.09.025

Figure Lengend Snippet: IL-21-secreting Salmonella promotes T cell infiltration and antitumor activity. The schedule for immune cell analysis is shown in A. (A, B) Tumor tissues obtained on Day 7 were fixed and processed for IF analysis. CD4 + and CD8 + T cells were analyzed using IF staining. (C, D) Granzyme B and Perforin levels in CD8 + T cells were analyzed using immunofluorescence staining. Scale bar = 50 μm. Image quantification data are presented in (E–H) ( n = 3). Significance is indicated by ∗ P < 0.05, ∗∗ P < 0.01, ns = not significant. Data are presented as the mean ± SEM.

Article Snippet: After collecting all supernatant samples, the IL-21 concentration was measured using a mouse IL-21 ELISA Kit (KE10012, Proteintech, Rosemont, IL, USA).

Techniques: Activity Assay, Cell Analysis, Staining, Immunofluorescence

Journal: Acta Pharmaceutica Sinica. B

Article Title: Attenuated Salmonella secreting interleukin-21 activates T-cells and induces anti-tumor effects

doi: 10.1016/j.apsb.2025.09.025

Figure Lengend Snippet: Antitumor efficacy of IL-21-secreting Salmonella combined with anti-PD-L1 antibody in tumor-bearing mice. (A) Schedule for combination therapy with IL-21-secreting Salmonella and anti-PD-L1 antibody. CT26 cells (5 × 10 5 ) were subcutaneously injected into the right flank of BALB/c mice. When the tumor size reached approximately 100 mm 3 , Salmonella (2 × 10 7 CFU) was administered intravenously, and simultaneously, anti-PD-L1 antibody (200 μg/mouse) was administered intraperitoneally four times starting from Day 0. Additionally, starting at 3 dpi, l -arabinose (80 mg/mouse) was administered daily via the intraperitoneal route. IL-21(−), without l -arabinose; IL-21(+), with l -arabinose. (B) Representative images of tumor-bearing mice. (C) Tumor volume at 2-day intervals. (D) Body weight changes for each treatment group. (E) Survival curves for each treatment group (data from B–E; n = 5). (F) TUNEL analysis of tumors from each treatment group. (G) Ki-67 expression images of tumors from each treatment group. Scale bar = 50 μm. Image quantification data are presented in (H, I) (data from F–I; n = 3). Significance is indicated at ∗∗ P < 0.01, ∗∗∗∗ P < 0.0001; ns = not significant. Data are presented as the mean ± SEM.

Article Snippet: After collecting all supernatant samples, the IL-21 concentration was measured using a mouse IL-21 ELISA Kit (KE10012, Proteintech, Rosemont, IL, USA).

Techniques: Injection, TUNEL Assay, Expressing

Journal: Acta Pharmaceutica Sinica. B

Article Title: Attenuated Salmonella secreting interleukin-21 activates T-cells and induces anti-tumor effects

doi: 10.1016/j.apsb.2025.09.025

Figure Lengend Snippet: IL-21-secreting Salmonella exhibits in vivo biosafety. (A) IL-21-secreting Salmonella (2 × 10 7 CFU) was administered intravenously, and observations were made at 2, 24, 48, 72, 168, and 336 h. (B) After Salmonella administration as described in (A), tissue homogenates of the heart, liver, spleen, lung, kidney, and tumor were cultured on solid LB agar plates and photographed on Days 1, 7, and 14. (C) Time-dependent quantitative distribution of Salmonella in tumors and major organs in each group (data from A; n = 3). (D) Number of IL-21-secreting Salmonella clones in major organs and tumors (Data from B; n = 3). Data are presented as mean ± standard deviation (E–H). ALT, AST, BUN, and CREA biochemical indicators were measured in the serum at Days 7, 14 and 21 post-administrations. The yellow-shaded areas indicate the average normal range ( n = 3). Data are presented as the mean ± SEM.

Article Snippet: After collecting all supernatant samples, the IL-21 concentration was measured using a mouse IL-21 ELISA Kit (KE10012, Proteintech, Rosemont, IL, USA).

Techniques: In Vivo, Cell Culture, Clone Assay, Standard Deviation