RT Journal Article SR Electronic T1 Trojan-horse silk fibroin nanocarriers loaded with a re-call antigen to redirect immunity against cancer JF Journal for ImmunoTherapy of Cancer JO J Immunother Cancer FD BMJ Publishing Group Ltd SP e005916 DO 10.1136/jitc-2022-005916 VO 11 IS 1 A1 Elia Bari A1 Francesca Ferrera A1 Tiziana Altosole A1 Sara Perteghella A1 Pierluigi Mauri A1 Rossana Rossi A1 Giulia Passignani A1 Luca Mastracci A1 Martina Galati A1 Giuseppina Iliana Astone A1 Maddalena Mastrogiacomo A1 Patrizio Castagnola A1 Daniela Fenoglio A1 Dario Di Silvestre A1 Maria Luisa Torre A1 Gilberto Filaci YR 2023 UL http://jitc.bmj.com/content/11/1/e005916.abstract AB Background The current challenge for immunotherapies is to generate effective antitumor immunity. Since tumor immune escape mechanisms do not impact pre-existing and consolidated immune responses, we tested the hypothesis of redirecting a pregenerated immunity to cancer: to recall a non-tumor antigen response against the tumor, silk fibroin nanoparticles (SFNs) have been selected as ‘Trojan-horse’ carriers, promoting the antigen uptake by the tumor cells.Methods SFNs have been loaded with either ovalbumin (OVA) or CpG oligonucleotide (CpG) as antigen or adjuvant, respectively. In vitro uptake of SFNs by tumor (B16/F10 melanoma and MB49 bladder cancer) or dendritic cells, as well as the presence of OVA-specific T cells in splenic and tumor-infiltrating lymphocytes, were assessed by cytometric analyses. Proof-of-concept of in vivo efficacy was achieved in an OVA-hyperimmune B16/F10 murine melanoma model: SFNs-OVA or SFNs-CpG were injected, separately or in association, into the subcutaneous peritumoral area. Cancer dimensions/survival time were monitored, while, at the molecular level, system biology approaches based on graph theory and experimental proteomic data were performed.Results SFNs were efficiently in vitro uptaken by cancer and dendritic cells. In vivo peritumor administration of SFNs-OVA redirected OVA-specific cytotoxic T cells intratumorally. Proteomics and systems biology showed that peritumoral treatment with either SFNs-OVA or SFNs-CpG dramatically modified tumor microenvironment with respect to the control (CTR), mainly involving functional modules and hubs related to angiogenesis, inflammatory mediators, immune function, T complex and serpins expression, redox homeostasis, and energetic metabolism. Both SFNs-OVA and SFNs-CpG significantly delayed melanoma growth/survival time, and their effect was additive.Conclusions Both SFNs-OVA and SFNs-CpG induce effective anticancer response through complementary mechanisms and show the efficacy of an innovative active immunotherapy approach based on the redirection of pre-existing immunity against cancer cells. This approach could be universally applied for solid cancer treatments if translated into the clinic using re-call antigens of childhood vaccination.All data relevant to the study are included in the article or uploaded as supplementary information. All data are available in the main text or the Supplemental materials.