Alphavirus‐driven interferon gamma (IFNG) expression inhibits tumor growth in orthotopic 4T1 breast cancer model

Olga Trofimova, Ksenija Korotkaja, Dace Skrastina, Juris Jansons, Karina Spunde, Maria Isaguliants, Anna Zajakina (Coresponding Author)

Research output: Contribution to journalArticlepeer-review

5 Citations (Scopus)
1 Downloads (Pure)


Interferon gamma (IFNg) is a pleiotropic cytokine that can potentially reprogram the tumor microenvironment; however, the antitumor immunomodulatory properties of IFNg still need to be validated due to variable therapeutic outcomes in preclinical and clinical studies. We developed a replication‐deficient Semliki Forest virus vector expressing IFNg (SFV/IFNg) and evaluated its immunomodulatory antitumor potential in vitro in a model of 3D spheroids and in vivo in an immunocompetent 4T1 mouse breast cancer model. We demonstrated that SFV‐derived, IFN‐g‐stimulated bone marrow macrophages can be used to acquire the tumoricidal M1 phenotype in 3D nonattached conditions. Coculturing SFV/IFNg‐infected 4T1 spheroids with BMDMs inhibited spheroid growth. In the orthotopic 4T1 mouse model, intratumoral administration of SFV/IFNg virus particles alone or in combination with the Pam3CSK4 TLR2/1 ligand led to significant inhibition of tumor growth compared to the administration of the control SFV/Luc virus particles. Analysis of the composition of intratumoral lymphoid cells isolated from tumors after SFV/IFNg treatment revealed increased CD4+ and CD8+ and decreased T‐reg (CD4+/CD25+/FoxP3+) cell populations. Furthermore, a significant decrease in the populations of cells bearing myeloid cell markers CD11b, CD38, and CD206 was observed. In conclusion, the SFV/IFNg vector induces a therapeutic antitumor T‐cell response and inhibits myeloid cell infiltration in treated tumors.

Original languageEnglish
Article number1247
Issue number11
Publication statusPublished - Nov 2021


  • Alphavirus
  • Bone‐marrow‐derived macrophages
  • Cancer immunotherapy
  • CD38
  • Interferon gamma
  • Pam3CSK4
  • Spheroids
  • Viral vectors

Field of Science*

  • 3.1 Basic medicine
  • 3.2 Clinical medicine
  • 3.3 Health sciences

Publication Type*

  • 1.1. Scientific article indexed in Web of Science and/or Scopus database


Dive into the research topics of 'Alphavirus‐driven interferon gamma (IFNG) expression inhibits tumor growth in orthotopic 4T1 breast cancer model'. Together they form a unique fingerprint.

Cite this