A Novel Recombinant Modified Vaccinia Ankara Virus expressing Interleukin-13 Receptor α2 Antigen for Potential Cancer Immunotherapy

Curr Mol Med. 2024;24(6):758-770. doi: 10.2174/1566524023666230331085007.

Abstract

Background: Genetically altered recombinant poxviruses hold great therapeutic promise in animal models of cancer. Poxviruses can induce effective cellmediated immune responses against tumor-associated antigens. Preventive and therapeutic vaccination with a DNA vaccine expressing IL-13Rα2 can mediate partial regression of established tumors in vivo, indicating that host immune responses against IL-13Rα2 need further augmentation.

Objective: The aim of the study is developing a recombinant modified vaccinia Ankara (MVA) expressing IL-13Rα2 (rMVA-IL13Rα2) virus and study in vitro infectivity and efficacy against IL-13Rα2 positive cell lines.

Methods: We constructed a recombinant MVA expressing IL-13Rα2 and a green fluorescent protein (GFP) reporter gene. Purified virus titration by infection of target cells and immunostaining using anti-vaccinia and anti-IL-13Rα2 antibodies was used to confirm the identity and purity of the rMVA-IL13Rα2.

Results: Western Blot analysis confirmed the presence of IL-13Rα2 protein (~52 kDa). Flow cytometric analysis of IL-13Rα2 negative T98G glioma cells when infected with rMVA-IL13Rα2 virus demonstrated cell-surface expression of IL-13Rα2, indicating the infectivity of the recombinant virus. Incubation of T98G-IL13Rα2 cells with varying concentrations (0.1-100 ng/ml) of interleukin-13 fused to truncated Pseudomonas exotoxin (IL13-PE) resulted in depletion of GFP+ fluorescence in T98G-IL13Rα2 cells. IL13-PE (10-1000 ng/ml) at higher concentrations also inhibited the protein synthesis in T98G-IL13Rα2 cells compared to cells infected with the control pLW44-MVA virus. IL13- PE treatment of rMVA-IL13Rα2 infected chicken embryonic fibroblast and DF-1 cell line reduced virus titer compared to untreated cells.

Conclusion: rMVA-IL13Rα2 virus can successfully infect mammalian cells to express IL-13Rα2 in a biologically active form on the surface of infected cells. To evaluate the efficacy of rMVA-IL13Rα2, immunization studies are planned in murine tumor models.

Keywords: GFP; IL-13Rα2; IL13-PE; MVA; green fluorescent protein; interleukin-13 fused to mutated form of Pseudomonas exotoxin.; interleukin-13 receptor α2; modified vaccinia ankara.

MeSH terms

  • Animals
  • Cancer Vaccines / genetics
  • Cancer Vaccines / immunology
  • Cell Line, Tumor
  • Exotoxins / genetics
  • Exotoxins / immunology
  • Genetic Vectors / genetics
  • Green Fluorescent Proteins / genetics
  • Green Fluorescent Proteins / metabolism
  • Humans
  • Immunotherapy* / methods
  • Interleukin-13 Receptor alpha2 Subunit* / genetics
  • Interleukin-13 Receptor alpha2 Subunit* / immunology
  • Interleukin-13 Receptor alpha2 Subunit* / metabolism
  • Neoplasms / immunology
  • Neoplasms / therapy
  • Pseudomonas aeruginosa Exotoxin A
  • Vaccinia virus* / genetics
  • Vaccinia virus* / immunology
  • Virulence Factors / genetics
  • Virulence Factors / immunology

Substances

  • Interleukin-13 Receptor alpha2 Subunit
  • Cancer Vaccines
  • Exotoxins
  • Pseudomonas aeruginosa Exotoxin A
  • Green Fluorescent Proteins
  • Virulence Factors

Supplementary concepts

  • Modified Vaccinia Ankara virus