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Direct incorporation of the NKT-cell activator α-galactosylceramide into a recombinant Listeria monocytogenes improves breast cancer vaccine efficacy
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 aga...
Autores principales: | , , , , , , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group
2014
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4229631/ https://www.ncbi.nlm.nih.gov/pubmed/25314062 http://dx.doi.org/10.1038/bjc.2014.486 |
Sumario: | 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. |
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