Pancreatic adenocarcinoma is one of the leading causes of cancer-related deaths, and its therapy remains a challenge. Our proposed therapeutic approach is based on the intratumoral injections of mannan-BAM, toll-like receptor ligands, and anti-CD40 antibody (thus termed MBTA therapy), and has shown promising results in the elimination of subcutaneous murine melanoma, pheochromocytoma, colon carcinoma, and smaller pancreatic adenocarcinoma (Panc02). Here, we tested the short- and long-term effects of MBTA therapy in established subcutaneous Panc02 tumors two times larger than in previous study and bilateral Panc02 models as well as the roles of CD4+ and CD8+ T lymphocytes in this therapy. The MBTA therapy resulted in eradication of 67% of Panc02 tumors with the development of long-term memory as evidenced by the rejection of Panc02 cells after subcutaneous and intracranial transplantations. The initial Panc02 tumor elimination is not dependent on the presence of CD4+ T lymphocytes, although these cells seem to be important in long-term survival and resistance against tumor retransplantation. The resistance was revealed to be antigen-specific due to its inability to reject B16-F10 melanoma cells. In the bilateral Panc02 model, MBTA therapy manifested a lower therapeutic response. Despite numerous combinations of MBTA therapy with other therapeutic approaches, our results show that only simultaneous application of MBTA therapy into both tumors has potential for the treatment of the bilateral Panc02 model.

• Klíčová slova
• Cancer immunotherapy, Checkpoint inhibitors, Mannan, Metastases, Pancreatic adenocarcinoma, TLR ligands,
• MeSH
• adenokarcinom imunologie   patologie   MeSH
• antigeny CD40 antagonisté a inhibitory   MeSH
• imidazoly farmakologie   MeSH
• imunoterapie MeSH
• kyseliny teichoové farmakologie   MeSH
• ligandy MeSH
• lipopolysacharidy farmakologie   MeSH
• mannany farmakologie   MeSH
• myši MeSH
• nádory slinivky břišní imunologie   patologie   MeSH
• poly I-C farmakologie   MeSH
• protokoly antitumorózní kombinované chemoterapie farmakologie   MeSH
• T-lymfocyty účinky léků   imunologie   MeSH
• toll-like receptory MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• antigeny CD40 MeSH
• imidazoly MeSH
• kyseliny teichoové MeSH
• ligandy MeSH
• lipopolysacharidy MeSH
• lipoteichoic acid MeSH Prohlížeč
• mannany MeSH
• poly I-C MeSH
• resiquimod MeSH Prohlížeč
• toll-like receptory MeSH

Immunotherapy emerges as a fundamental approach in cancer treatment. Up to date, the efficacy of numerous different immunotherapies has been evaluated. The use of microorganisms or their parts for immune cell activation, referred to as Pathogen-Associated Molecular Patterns (PAMPs), represents highly promising concept. The therapeutic effect of PAMPs can be further amplified by suitable combination of different types of PAMPs such as Toll like receptor (TLR) agonists and phagocytosis activating ligands. Previously, we used the combination of phagocytosis activating ligand (mannan) and mixture of TLR agonists (resiquimod (R-848), poly(I:C), inactivated Listeria monocytogenes) for successful treatment of melanoma in murine B16-F10 model. In the present study, we optimized the composition and timing of previously used mixture. Therapeutic mixture based on well-defined chemical compounds consisted of mannan anchoring to tumor cell surface by biocompatible anchor for membranes (BAM) and TLR agonists resiquimod, poly(I:C), and lipoteichoic acid (LTA). The optimization resulted in (1) eradication of advanced stage progressive melanoma in 83% of mice, (2) acquisition of resistance to tumor re-transplantation, and (3) potential anti-metastatic effect. After further investigation of mechanisms, underlying anti-tumor responses, we concluded that both innate and adaptive immunity are activated and involved in these processes. We tested the efficacy of our treatment in Panc02 murine model of aggressive pancreatic tumor as well. Simultaneous application of agonistic anti-CD40 antibody was necessary to achieve effective therapeutic response (80% recovery) in this model. Our results suggest that herein presented immunotherapeutic approach is a promising cancer treatment strategy with the ability to eradicate not only primary tumors but also metastases.

• Klíčová slova
• Cancer immunotherapy, Melanoma B16-F10, Metastasis, Panc02, Phagocytosis, TLR agonists,
• MeSH
• adenokarcinom imunologie   patologie   terapie   MeSH
• fagocytóza * MeSH
• imidazoly terapeutické užití   MeSH
• imunoterapie MeSH
• kyseliny teichoové terapeutické užití   MeSH
• lipopolysacharidy terapeutické užití   MeSH
• mannany terapeutické užití   MeSH
• melanom experimentální imunologie   patologie   terapie   MeSH
• myši inbrední C57BL MeSH
• nádorové buněčné linie MeSH
• nádory slinivky břišní imunologie   patologie   terapie   MeSH
• neutrofily imunologie   MeSH
• poly I-C terapeutické užití   MeSH
• toll-like receptory agonisté   MeSH
• tumor burden účinky léků   MeSH
• tumor infiltrující lymfocyty imunologie   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• imidazoly MeSH
• kyseliny teichoové MeSH
• lipopolysacharidy MeSH
• lipoteichoic acid MeSH Prohlížeč
• mannany MeSH
• poly I-C MeSH
• resiquimod MeSH Prohlížeč
• toll-like receptory MeSH