Related Experiment Video
Updated: Sep 25, 2025
Multiplexed Immunofluorescence Analysis and Quantification of Intratumoral PD-1+ Tim-3+ CD8+ T Cells
Published on: February 8, 2018
Decrease of Tumor-infiltrating Regulatory T Cells Using Pentoxifylline: An Ex Vivo Analysis in Triple-negative Breast
Mohammad Hossein Kazemi1, Mahdieh Shokrollahi Barough2, Alireza Ghanavatinejad3
1Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran AND Department of ATMP, Breast Cancer Research Center, Motamed Cancer Institute, ACECR, Tehran, Iran. Kazemi.m03@iums.ac.ir.
Abstract:
Triple-negative breast cancer (TNBC) is the most aggressive type of BC with the highest percentage of tumor-infiltrating lymphocytes (TILs). Hence, TIL therapy is considered a promising approach to target TNBC. Depletion of regulatory T cells (Tregs) in TILs can improve the antitumor function of TIL therapy. Pentoxifylline (PTXF) is a xanthine derivative that can modulate the nuclear factor kappa B (NF-κB) signaling and probably affect the Treg proportion in TILs. We aimed to evaluate the ex vivo effect of PTXF on the proportion of Treg cells in the TILs derived from a mouse model of TNBC. The 4T1 cells were inoculated subcutaneously to BALB/c mice to induce TNBC. TILs were isolated from tumor tissue by enzymatic digestion and cultured alone or with 4T1 cells for 24, 48, and 72 h in the presence of interleukin (IL)-2 and different concentrations of PTXF. The toxicity of PTXF and its effects on Tregs proportion as well as cytokine production was evaluated using MTT assay, flow cytometry, and ELISA, respectively. PTXF had no significant impact on the viability of TILs. Both 500 and 1000 mg/mL of PTXF decreased the proportion of Tregs in a dose-dependent manner. The level of interferon-g and tumor growth factor-b in TILs supernatant was increased and decreased, respectively. Our data suggest that ex vivo treatment of TILs with pentoxifylline could decrease the proportion of Tregs in the conventional IL-2-mediated TIL expansion and change the cytokine balance of TILs in favor of antitumor immune response.
Insights
Pentoxifylline (PTXF) effectively reduces regulatory T cells (Tregs) in tumor-infiltrating lymphocytes (TILs) from triple-negative breast cancer (TNBC) models without impacting cell viability. This suggests PTXF can enhance TIL therapy by modulating immune responses.
Area of Science:
- Immunology
- Oncology
- Pharmacology
Background:
- Triple-negative breast cancer (TNBC) is aggressive and characterized by high tumor-infiltrating lymphocytes (TILs).
- TIL therapy shows promise for TNBC, but regulatory T cells (Tregs) within TILs can suppress anti-tumor immunity.
- Pentoxifylline (PTXF), a xanthine derivative, may modulate immune cell populations, including Tregs.
Purpose of the Study:
- To investigate the ex vivo effects of pentoxifylline (PTXF) on the proportion of regulatory T cells (Tregs) within tumor-infiltrating lymphocytes (TILs) from a mouse model of triple-negative breast cancer (TNBC).
- To assess the impact of PTXF on TIL viability and cytokine production in the context of IL-2-mediated expansion.
Main Methods:
- TNBC was induced in BALB/c mice using 4T1 cells.
- TILs were isolated and cultured with or without 4T1 cells, IL-2, and varying concentrations of PTXF for 24-72 hours.
- Cell viability (MTT assay), Treg proportion (flow cytometry), and cytokine levels (ELISA) were analyzed.
Main Results:
- Pentoxifylline (PTXF) demonstrated no significant toxicity to TILs at tested concentrations.
- PTXF significantly decreased the proportion of Tregs in a dose-dependent manner.
- PTXF altered cytokine profiles, increasing interferon-gamma and decreasing tumor growth factor-beta.
Conclusions:
- Ex vivo treatment with pentoxifylline can reduce Treg populations during IL-2-mediated TIL expansion for TNBC.
- PTXF treatment shifts the cytokine balance in TILs towards an anti-tumor immune response.
- Pentoxifylline represents a potential adjuvant therapy to enhance TIL-based immunotherapy for TNBC.
