Innate immunity based cancer immunotherapy: B16-F10 murine melanoma model

Abstract

BackgroundUsing killed microorganisms or their parts to stimulate immunity for cancer treatment dates back to the end of 19th century. Since then, it undergone considerable development. Our novel approach binds ligands to the tumor cell surface, which stimulates tumor phagocytosis. The therapeutic effect is further amplified by simultaneous application of agonists of Toll-like receptors. We searched for ligands that induce both a strong therapeutic effect and are safe for humans.MethodsB16-F10 murine melanoma model was used. For the stimulation of phagocytosis, mannan or N-formyl-methionyl-leucyl-phenylalanine, was covalently bound to tumor cells or attached using hydrophobic anchor. The following agonists of Toll-like receptors were studied: monophosphoryl lipid A (MPLA), imiquimod (R-837), resiquimod (R-848), poly(I:C), and heat killed Listeria monocytogenes.ResultsR-848 proved to be the most suitable Toll-like receptor agonist for our novel immunotherapeutic approach. In combination with covalently bound mannan, R-848 significantly reduced tumor growth. Adding poly(I:C) and L. monocytogenes resulted in complete recovery in 83% of mice and in their protection from the re-transplantation of melanoma cells.ConclusionAn efficient cancer treatment results from the combination of Toll-like receptor agonists and phagocytosis stimulating ligands bound to the tumor cells.Electronic supplementary materialThe online version of this article (doi:10.1186/s12885-016-2982-x) contains supplementary material, which is available to authorized users.

Induction of Immune Response against Metastatic Tumors via Vaccination of Mannan‐BAM, TLR Ligands, and Anti‐CD40 Antibody (MBTA)

“…Mannan‐BAM synthesis was performed as previously reported. [ 9,11,14 ] Aminated mannan was prepared by reductive amination. [ 42 ] Mannan solution in an environment of ammonium acetate (300 mg mL −1 ) was reduced by 0.2 m sodium cyanoborohydride at pH 7.5 and 50 °C for five days.…”

“…To bolster mannan‐BAM's inductive effect on innate immune cells, three TLR ligands (lipoteichoic acid (LTA), polyinosinic‐polycytidylic acid poly(I:C), and resiquimod (R‐848)) and immunostimulatory anti‐CD40‐mAb were incorporated as adjuvants. [ 8,9,11,13–15 ] LTA from Bacillus subtilis activates TLR2 mediated inflammatory pathways known to increase TNFα secretion. [ 16,17 ] Poly(I:C), a synthetic analog of viral dsRNA, activates TLR3 mediated signaling previously demonstrated to activate antigen‐presenting cells (APCs), modulate the phenotype of tumor associated macrophages to more immunosupportive phenotypes, and induce tumor cell apoptosis.…”

The Significant Reduction or Complete Eradication of Subcutaneous and Metastatic Lesions in a Pheochromocytoma Mouse Model after Immunotherapy Using Mannan-BAM, TLR Ligands, and Anti-CD40

“…Recently, immunotherapy based on the activation of innate immunity via pathogen-associated molecular patterns (PAMPs) has been tested in melanoma, which is also a neural crest tumor. Intratumoral application of PAMPs, particularly ligands stimulating phagocytosis and toll-like receptor (TLR) ligands, resulted in the complete elimination of over 80% of subcutaneous tumors in the B16-F10 melanoma mouse model [15,16,17].…”

“…Ligands stimulating phagocytosis initiate ingestion of pathogens by phagocytic immune cells [18,19]. PAMP-based immunotherapy uses intratumoral administration of mannan, a simple polysaccharide from Saccharomyces cerevisiae, as a ligand stimulating phagocytosis [16]. Mannan recognized by mannan-binding lectin (MBL) activates the complement lectin pathway [20].…”

Pigmented melanoma cell migration study on murine syngeneic B16F10 melanoma cells or tissue transplantation models

“…Melanoma is an aggressive and lethal form of skin cancer with a poor prognosis, especially due to its susceptibility to early distant metastasis (1), even from primary non-identifiable tumors (2). Several murine melanoma models, including syngeneic or xenograft transplantation, genetically modified models, ultraviolet radiation, or chemically induced melanoma, have been developed in recent decades to study the tumor line selection and cancer immunology (3,4), to elucidate the mechanisms of melanoma progression and metastasis (5)(6)(7)(8), and to design and evaluate the novel anticancer therapeutic agents (9)(10)(11).…”