-Derived Molecules Induce Anti-Tumour Protection by Favouring Both Innate and Adaptive Immune Responses

Lung cancer remains the leading cause of cancer mortality worldwide. Thus, the development of strategies against this type of cancer is of high value. Parasite infections can correlate with lower cancer incidence in humans and their use as vaccines has been recently explored in preclinical models. In this study, we investigated whether immunisations with a lysate from epimastigotes protect from lung tumour growth in mice. We also explore the role of parasite glycans in the induction of the protective immune response. A pre-clinical murine cancer model using the lung tumour cell line LL/2 was used to evaluate the anti-tumour potential, both in preventive and therapeutic settings, of a epimastigote-derived protein lysate. Immunisation with the parasite lysate prevents tumour growth and induces both humoral and cellular anti-tumour immune responses to LL-2 cancer cells. The induced immunity and tumour protection were associated with the activation of natural killer (NK) cells, the production of interferon-γ (IFN-γ) and tumour cell cytotoxicity. We also show that mannose residues in the lysate induce Toll-like receptor (TLR) signalling. The evaluated lysate possesses anti-tumour properties likely by activating innate and adaptive immunity in a process where carbohydrates seem to be essential.