iScience (Jun 2020)

A Structurally Simple Vaccine Candidate Reduces Progression and Dissemination of Triple-Negative Breast Cancer

  • Amedeo Amedei,
  • Fatemeh Asadzadeh,
  • Francesco Papi,
  • Maria Giuliana Vannucchi,
  • Veronica Ferrucci,
  • Iris A. Bermejo,
  • Marco Fragai,
  • Carolina Vieira De Almeida,
  • Linda Cerofolini,
  • Stefano Giuntini,
  • Mauro Bombaci,
  • Elisa Pesce,
  • Elena Niccolai,
  • Francesca Natali,
  • Eleonora Guarini,
  • Frank Gabel,
  • Chiara Traini,
  • Stefano Catarinicchia,
  • Federica Ricci,
  • Lorenzo Orzalesi,
  • Francesco Berti,
  • Francisco Corzana,
  • Massimo Zollo,
  • Renata Grifantini,
  • Cristina Nativi

Journal volume & issue
Vol. 23, no. 6
p. 101250

Abstract

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Summary: The Tn antigen is a well-known tumor-associated carbohydrate determinant, often incorporated in glycopeptides to develop cancer vaccines. Herein, four copies of a conformationally constrained mimetic of the antigen TnThr (GalNAc-Thr) were conjugated to the adjuvant CRM197, a protein licensed for human use. The resulting vaccine candidate, mime[4]CRM elicited a robust immune response in a triple-negative breast cancer mouse model, correlated with high frequency of CD4+ T cells and low frequency of M2-type macrophages, which reduces tumor progression and lung metastasis growth. Mime[4]CRM-mediated activation of human dendritic cells is reported, and the proliferation of mime[4]CRM-specific T cells, in cancer tissue and peripheral blood of patients with breast cancer, is demonstrated. The locked conformation of the TnThr mimetic and a proper presentation on the surface of CRM197 may explain the binding of the conjugate to the anti-Tn antibody Tn218 and its efficacy to fight cancer cells in mice.

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