1. Academic Validation
  2. Flagellin synergistically enhances anti-tumor effect of EGFRvIII peptide in a glioblastoma-bearing mouse brain tumor model

Flagellin synergistically enhances anti-tumor effect of EGFRvIII peptide in a glioblastoma-bearing mouse brain tumor model

  • BMC Cancer. 2022 Sep 15;22(1):986. doi: 10.1186/s12885-022-10023-6.
Jin Myung Choi # 1 Sa-Hoe Lim # 1 2 Zhi-Peng Liu 1 Tae Kyu Lee 2 Joon Haeng Rhee 3 Mee Sun Yoon 4 Jung-Joon Min 5 Shin Jung 6 7
Affiliations

Affiliations

  • 1 Brain Tumor Research Laboratory, Biomedical Research Institute, Chonnam National University Hwasun Hospital, Hwasun, 58128, Republic of Korea.
  • 2 Department of Neurosurgery, Chonnam National University Hwasun Hospital &School of Medicine, 322 Seoyang-ro, Hwasun, 58128, Republic of Korea.
  • 3 Department of Microbiology, Chonnam National University Medical School, Hwasun, 58128, Republic of Korea.
  • 4 Department of Radiation Oncology, Chonnam National University Hwasun Hospital &Medical School, Hwasun, 58128, Republic of Korea.
  • 5 Department of Nuclear Medicine, Chonnam National University Medical School, Hwasun, 58128, Republic of Korea.
  • 6 Brain Tumor Research Laboratory, Biomedical Research Institute, Chonnam National University Hwasun Hospital, Hwasun, 58128, Republic of Korea. sjung@chonnam.ac.kr.
  • 7 Department of Neurosurgery, Chonnam National University Hwasun Hospital &School of Medicine, 322 Seoyang-ro, Hwasun, 58128, Republic of Korea. sjung@chonnam.ac.kr.
  • # Contributed equally.
Abstract

Background: Glioblastoma (GBM) is the most aggressive type of brain tumor with heterogeneity and strong invasive ability. Treatment of GBM has not improved significantly despite the progress of immunotherapy and classical therapy. Epidermal growth factor receptor variant III (EGFRvIII), one of GBM-associated mutants, is regarded as an ideal therapeutic target in EGFRvIII-expressed GBM patients because it is a tumor-specific receptor expressed only in tumors. Flagellin B (FlaB) originated from Vibrio vulnificus, is known as a strong Adjuvant that enhances innate and adaptive immunity in various vaccine models. This study investigated whether FlaB synergistically could enhance the anti-tumor effect of EGFRvIII peptide (PEGFRvIII).

Methods: EGFRvIII-GL261/Fluc cells were used for glioblastoma-bearing mouse brain model. Cell-bearing mice were inoculated with PBS, FlaB alone, PEGFRvIII alone, and PEGFRvIII plus FlaB. Tumor growth based on MRI and the survival rate was investigated. T cell population was examined by flow cytometry analysis. Both cleaved Caspase-3 and CD8 + lymphocytes were shown by immunohistochemistry (IHC) staining.

Results: The PEGFRvIII plus FlaB group showed delayed tumor growth and increased survival rate when compared to other treatment groups. As evidence of Apoptosis, cleaved Caspase-3 expression and DNA disruption were more increased in the PEGFRvIII plus FlaB group than in other groups. In addition, the PEGFRvIII plus FlaB group showed more increased CD8 + T cells and decreased Treg cells than other treatment groups in the brain.

Conclusions: FlaB can enhance the anti-tumor effect of PEGFRvIII by increasing CD8 + T cell response in a mouse brain GBM model.

Keywords

Adjuvant; EGFRvIII; Flagellin; Glioblastoma; Immunotherapy.

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