Direct incorporation of the NKT-cell activator α-galactosylceramide into a recombinant Listeria monocytogenes improves breast cancer vaccine efficacy

M. Singh, W. Quispe-Tintaya, D. Chandra, A. Jahangir, M. M. Venkataswamy, T. W. Ng, S. Sharma-Kharkwal, L. J. Carreño, S. A. Porcelli, C. Gravekamp

Research output: Contribution to journalArticle

14 Scopus citations


Background:Immune suppression in the tumour microenvironment remains a major limitation to successful immunotherapy of cancer. In the current study, we analysed whether the natural killer T cell-activating glycolipid α-galactosylceramide could overcome immune suppression and improve vaccination against metastatic breast cancer.Methods:Mice with metastatic breast cancer (4T1 model) were therapeutically treated with a Listeria monocytogenes-based vaccine expressing tumour-associated antigen Mage-b followed by α-galactosylceramide as separate agents, or as a complex of α-galactosylceramide stably incorporated into Listeria-Mage-b. Effects on metastases, tumour weight, toxicity and immune responses were determined.Results:Sequential treatments of mice with established 4T1 breast carcinomas using Listeria-Mage-b followed by α-galactosylceramide as a separate agent was highly effective at reducing metastases, but was accompanied by severe liver toxicity. In contrast, combined therapy using Listeria-Mage-b modified by incorporation of α-galactosylceramide resulted in nearly complete elimination of metastases without toxicity. This was associated with a significant increase in the percentage of natural killer T cells in the spleen, and an increase in natural killer cell activity and in T cell responses to Mage-b.Conclusions:Our results suggest that direct incorporation of α-galactosylceramide into a live bacterial vaccine vector is a promising non-toxic new approach for the treatment of metastatic breast cancer.

Original languageEnglish (US)
Pages (from-to)1945-1954
Number of pages10
JournalBritish Journal of Cancer
Issue number10
StatePublished - Nov 11 2014



  • Listeria monocytogenes
  • NKT cells
  • a-galactosylceramide
  • breast cancer
  • metastases

ASJC Scopus subject areas

  • Oncology
  • Cancer Research

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