Some oncolytic viruses, such as talimogene laherparepvec, are FDA approved and are already in phase III clinical trials for the treatment of melanoma patients [157], facilitating their implementation in glioma combination treatment approaches

Some oncolytic viruses, such as talimogene laherparepvec, are FDA approved and are already in phase III clinical trials for the treatment of melanoma patients [157], facilitating their implementation in glioma combination treatment approaches. carboxy-terminal hydrolase Nanomedicine-based immunotherapy for glioblastoma The cargo-based delivery of therapeutic agents, which induce an immune response, is a topic of high interest in glioma treatment, as highlighted in a recent article, glioblastoma is hot for personalized vaccines [90]. A detailed schematic illustration of the immune response in glioblastoma is shown in Fig.?2. Open in a separate window Fig. 2 Optimal design of nanoparticle-based delivery of drugs, cargoes/or adjuvants, and immunotherapy of FKBP4 glioblastoma.Diverse types of nanoscale materials can serve as vehicles for targeted delivery of tumor-cytotoxic nanomedicines Immunotherapy for glioblastoma relies on the dendritic cell (DC)-mediated presentation of tumor-associated peptides, antigens, or epitopes (used in vaccination therapy) [91]. These tumor lysate-derived constituents are administered directly or through CAR T cells for adaptive immune organization. Then, cytotoxic T lymphocytes (CTLs) are activated after interacting with DCs via the major histocompatibility complex (MHC) class IICT-cell receptor (TCR) (signal 1) and CD80/CD86-CD28 (signal 2). Upon activation, CTLs interrogate glioblastoma-associated antigens expressed on MHC class I molecules and destroy tumor cells [92, 93]. However, BMS-819881 glioblastoma cells frequently avoid obliteration through enhanced expression of immune checkpoint ligands, such as programmed death-ligand 1 (PD-L1) receptors. These ligand receptors bind with complementary receptors on CTLs via PD-1 and cause the suppression of CTL activation. BMS-819881 Immune checkpoint blockade therapy with monoclonal antibodies can disrupt this communication [94, 95]. Moreover, the inhibitory immune checkpoint blockade of cytotoxic T lymphocyte protein 4 (CTLA-4) also stimulates the interaction of CD28 with CD80 and CD86 on DCs and promotes T-cell priming. Glioblastoma-associated antigens, containing IL-13 receptor subunit-2 and epidermal growth factor receptor (EGFR) variant III, are also expressed on the tumor cell surface and can BMS-819881 self-regulate MHC class I [96]. These tumor-associated antigens are exploited as specific targets of genetically modified CAR T-cell therapies [97]. A summary of the advantages and disadvantages of various immunotherapy-based strategies for the treatment of glioblastoma is presented in Table?2. Table 2 Comparison of multiple nanomedicine-based immunotherapies for glioblastoma gene (AdV-tk) to enhance anti-PD-1 efficacy in syngeneic glioblastoma-bearing mouse models [152]. AdV-tk upregulated IFN signaling and enhanced PD-L1 levels, while cytotoxic CD8+ T cells were allowed to accumulate in tumors. The combination of gene therapy with immunotherapy significantly increased the percentage of long-term survival in glioblastoma-bearing animals from 30%C50% (treatment with single agents) to 88% [152]. Despite the promise of gene combination therapy for glioblastoma, this approach is still hindered by an inefficient delivery system to tumor sites [153, 154]. Recently, nanoparticles have overcome these shortfalls to deliver gene-mediated immunotherapeutic agents to brain tumors [155]. Erel-Akbaba et al. [156] developed a solid lipid nanoparticle (SLN) decorated with the cyclic peptide iRGD (CCRGDKGPDC) to deliver siRNAs against both EGFR and PD-L1 (Fig.?6). When the cyclic peptide iRGD is conjugated to nanoparticles, this enables the nanoparticles to cross the BBB and enhances the targeting ability of this therapy in glioblastoma-bearing mice. Moreover, the SLN possesses a strong degree of lipophilicity and a positive charge that facilitates BBB penetration. After binding with siRNA, the hydrodynamic size of the f(SLN)CiRGD:siRNA complex was measured to be 24.1?nm with a positive charge around the complex. Nanoparticle f(SLN)CiRGD:siRNA treatment led to the downregulation of PD-L1 and EGFR expression levels by 8.6% and 54.7%, respectively [156]. Furthermore, the median survival of the mice treated with f(SLN)CiRGD:siRNA BMS-819881 combined with radiation increased to 38 days from 21 days (control group) [156]. To date, gene therapy has mostly been applied to enhance systemic therapy for glioma treatment, but it can also significantly regulate immunosuppressive signals. Some oncolytic viruses, such as talimogene laherparepvec, are FDA approved and are already in phase III clinical trials for the treatment of melanoma patients [157], facilitating their implementation in.