This study will focus on optimization of cancer immunotherapy and overcoming mechanisms that enable tumor cells to evade anti-tumor immune reactions. This work will be performed on the mouse TC-1 tumor model. To stimulate anti-tumor immunity, adaptive immunity will be induced by DNA immunization and innate immunity, particularly repolarization of tumor-associated macrophages into tumoricidal M1 phenotype, will be activated by adjuvants. Immunotherapy will attempt to overcome three tumor escape mechanisms: downregulation of MHC-I expression, immunosuppression mediated by checkpoint receptors, and immunosuppression caused by enzymatic activity of IDO1. Overcoming MHC-I downregulation will be studied by using TC-1 clones with both reversibly and irreversibly reduced MHC-I expression, activation of checkpoint signaling will be blocked by monoclonal antibodies, and IDO1 will be inactivated by a small molecular inhibitor. Tumor microenvironment will be analyzed to reveal other mechanisms contributing to tumor progression. Infiltrating immune cells will be characterized by flow cytometry. Immunohistochemical staining will be used to test some parameters of tumor microenvironment and identify areas with different properties, such as hypoxia, infiltration with immune cells, and vitality of tumor cells. After laser capture microdissection, RNA from these areas will be sequenced and differential gene expression will be analyzed to characterize positional and temporal heterogeneity of tumors. Further improvements of combined immunotherapy will be advised based on the results of tumor-heterogeneity analysis.
Grzelak A, Polakova I, Smahelova J, Vackova J, Pekarcikova L, Tachezy R and Smahel M: Experimental combined immunotherapy of tumours with major histocompatibility complex class I downregulation. Int J Mol Sci 2018, 19: 3693
Smahel M, Polakova I, Duskova M, Ludvikova V, Kastankova I. The effect of helper epitopes and cellular localization of an antigen on the outcome of gene gun DNA immunization. Gene Ther 2014; 21: 225-32.
Smahel M. Biolistic DNA vaccination against cervical cancer. Methods Mol Biol 2013; 940: 339-55.
Smahel M, Tejklova P, Smahelova J, Polakova I, Mackova J. Mutation in the immunodominant epitope of the HPV16 E7 oncoprotein as a mechanism of tumor escape. Cancer Immunol Immunother 2008; 57: 823-31.
Smahel M, Sima P, Ludvikova V, Marinov I, Pokorna D, Vonka V. Immunisation with modified HPV16 E7 genes against mouse oncogenic TC-1 cell sublines with downregulated expression of MHC class I molecules. Vaccine 2003; 21: 1125-36.
Center for Tumor Ecology – Research of the Cancer Microenvironment Supporting Cancer Growth and Spread, participation (Excellent Research, Czech Ministry of Education, Youth and Sports (MEYS), 2018-2023)
The role of aspartyl beta-hydroxylase in tumors associated and non-associated with human papillomaviruses, participation (Inter-Excellence, Inter-Action LTAUSA18, MEYS, 2019-2022)
Experimental cancer immunotherapy, tumor heterogeneity, and overcoming tumor immune escape (Czech Science Foundation, 2019-2021)
BIOCEV - from Fundamental to Applied Research, participation (MEYS, 2016-2020)
Experimental cancer immunotherapy, tumor heterogeneity, and overcoming tumor immune escape (Czech Science Foundation, 2019-2021)
Deadline is closed