Fig. 8
From: Cold and hot tumors: from molecular mechanisms to targeted therapy
Nanoparticle-Mediated Tumor Microenvironment Intrinsic Immunomodulation Enhancing Cancer Immunotherapy. Engineered nanoparticles administered via subcutaneous or intravenous injection are internalized by either innate immune cells or tumor cells, releasing various payloads in lymph nodes, the tumor immune microenvironment, and vasculature. Nanoparticles possess the capacity to selectively target innate immune pathways, thereby augmenting innate immune responses against cancer. This is primarily due to the stimulation of innate immune cells by released agonists/antigens. This stimulation initiates the secretion of pro-immunogenic cytokines downstream, which subsequently enhances T-cell activation and infiltration in lymph node. Consequently, this process enhances the anti-tumoral immune responses of cytotoxic T lymphocytes (CTLs). Furthermore, nanoparticles effectively modulate the immunosuppressive tumor microenvironment (TME), improving tumors’ sensitivity to immunotherapy by engaging in specific interactions with innate immune cells. This includes elevating the presence of neutrophils and natural killer (NK) cells at tumor sites, diminishing the functions of M2 macrophages and myeloid-derived suppressor cells (MDSCs), transforming M2 macrophages into the M1 phenotype, and inciting the activation of NK cells. In this context, red arrows represent promotion, while black bars symbolize inhibition. This figure was created using Figdraw
