Imunomodulação do microambiente do câncer de mama por nanopartículas de HA-PEI-PLGA-MTX combinado ao anti-PD-L1 via supressão do eixo de sinalização IL-10/STAT3/NF-kB

Abstract

Inflammation associated with the tumour microenvironment in triple negative breast cancer is closely related to the development and progression of the tumour. In this sense understand the involved mechanisms, as well as ways to combat the inflammatory process is challenging and has been widely investigated. In this study, a novel immunotherapeutic approach that combines the use of anti-PD-L1 immune checkpoint inhibitor and PLGA-based methotrexate (MTX) nanocarrier, covered with polyethyleneimine (Pei) and hyaluronic acid (HA) is suggested as way to reduce the development and progression of breast cancer through immunomodulating its tumour microenvironment. From the allographic model of orthotopic breast cancer development, the tumours were evaluated by qRT-PCR and immunohistochemistry. Complementary analysis of biocompatibility and internalization of nanoparticles, as well as the investigation of cell death profile, cells migration and polarization of macrophages were evaluated in vitro by flow cytometry and immunofluorescence. Naked or HA-coated PeiPLGA-MTX nanoparticles, alone or combined with anti-PDL1, were able to slow the tumours development, as well as liver metastases in vivo. A significant reduction of tumour development markers expression, such as NF-κB and STAT3, BCL-2, Survivin, MDR1 and Vimentin, was observed. In addition, such treatments also promoted an increase in the amount of T CD8 and M1 macrophages (CD68) effector cells, as well as a significant reduction in M2 macrophages (CD163) and immunosuppressive molecules such as IL-10, TGF-β, CCL22 and PD-L1 in the tumour microenvironment. Such results shed light on the understanding of immunological mechanisms that underlie tumour progression and brings up a promising drug carrier based on PLGA nanoparticles capable of satisfactorily modulating the immunological tumour microenvironment of breast cancer via IL10/STAT3/NF-κB signaling axis suppression, especially in M2 macrophages.