Tumor necrosis factor (TNF) has been recognized as an immune activation factor in tumor immunotherapy. Our study demonstrated that TNF blockade markedly enhanced the antitumor efficacy of oncolytic adenovirus (AdV) therapy. To minimize systemic side effects, we engineered a recombinant oncolytic AdV encoding a TNF inhibitor (AdV-TNFi) to confine TNF blockade within the tumor microenvironment (TME). AdV-TNFi significantly improved therapeutic outcomes across various solid tumor models, including four murine and two golden hamster cancers. Immune cell profiling identified CD8 + T cells as the primary mediators of AdV-TNFi-induced antitumor effects, rather than CD4 + T or NK cells. Additionally, AdV-TNFi significantly decreased the infiltration of suppressive myeloid-derived immune cells within the TME and promoted long-term antitumor immune surveillance. Further investigation indicated that TNFR2, more than TNFR1, is pertinent to the immunosuppressive TME, with a recombinant AdV-encoding anti-TNFR2 demonstrating comparable antitumor efficacy to AdV-TNFi. Moreover, AdV-TNFi enhanced the antitumor efficacy of gemcitabine and immune checkpoint blockades (ICBs), such as anti-PD-L1 and anti-TIGIT antibodies, in pancreatic carcinoma and the anti-EGFR antibody in colon carcinoma. In conclusion, intratumoral blockade of the TNF/TNFR2 axis using AdV augments cancer immunotherapy efficacy while mitigating the risks associated with systemic TNF or TNFR2 suppression, warranting further clinical investigation.
Using entire tumor cells or tissues that display both common and patient-specific antigens can potentially trigger a comprehensive and long-lasting anti-tumor immune response. However, the limited immunogenicity, low uptake efficiency, and susceptibility to degradation of whole-component antigens present significant challenges. In this study, we employed tumor lysates (TLs) as whole-component antigens, in conjunction with MgAl-layered double hydroxide (MA) as nanoadjuvants and Mn 2+ as immunostimulants, to create personalized MMAT (Mn 2+ -MA-TLs) nanovaccines. After subcutaneous injection of MMAT nanovaccines, the high local concentrations of TLs and Mn 2+ facilitated the recruitment and activation of antigen-presenting cells (APCs), thereby inducing a robust adaptive immune response. Remarkably, MMAT nanovaccines enabled lysosomal escape, enhanced antigen cross-presentation, and activated the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway in APCs. Furthermore, MMAT nanovaccines, when combined with the anti-TIGIT monoclonal antibody (aTIGIT), an immune checkpoint inhibitor, not only stimulated T-cell-based adaptive anti-tumor immune responses but also activated the NK-cell-based innate anti-tumor immunity, effectively suppressing tumor growth, recurrence, and metastasis. Thus, the ternary MMAT nanovaccines developed here introduced a pioneered paradigm for the rapid preparation of whole-component tumor antigens with nanoadjuvants and immunostimulants into nanovaccines, offering new prospects for clinical immunotherapies.
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