CSIG-17. IMMUNE MODULATORY ROLE OF TYPE I INTERFERON IN SYNGENEIC MOUSE GLIOMA MODELS

2021 ◽  
Vol 23 (Supplement_6) ◽  
pp. vi36-vi37
Author(s):  
Evelina Blomberg ◽  
Manuela Silginer ◽  
Michael Weller
Keyword(s):  
Tumor Cells ◽  
Immune Cell ◽  
Synergistic Effects ◽  
Xenograft Model ◽  
Prolonged Survival ◽  
Type I ◽  
Syngeneic Mouse ◽  
Glioma Initiating Cells ◽  
Glioma Growth

Abstract Glioblastoma is characterized by a poor prognosis and a challenging phenotype for drug development. Although multimodal treatment, including surgery, radio- and chemotherapy is applied, the overall survival remains just above one year. Numerous clinical trials have studied targeted therapies against commonly deregulated pathways, but an efficient targeted drug is yet to be discovered. Likewise, immunotherapy has not been shown to be active. A subset of glioma tumor cells demonstrates stem-like properties; these cells are commonly referred to as glioma initiating cells (GIC). These types of cells are pluripotent and can by definition initiate and recapitulate glioma growth in experimental animals in vivo. Furthermore, these cells are often resistant to conventional therapies. Interferon β (IFN-β) is an immunomodulatory molecule with anti-cancer properties. We have previously shown that IFN-β greatly reduces sphere-formation capability of GIC. It was also confirmed that IFN-β sensitized resistant GIC to irradiation or the chemotherapeutic agent, temozolomide (TMZ). IFN-β treatment significantly prolonged survival in a xenograft model with GIC cells. In the current project, we want to use syngeneic mouse models to study the immunomodulatory effects of type I IFNs. Preliminary results indicate that abrogation of IFN signalling in tumor cells by CRISPR/Cas9 technology prolonged survival in mice only in cell lines which have substantial baseline autocrine IFN signalling. On the contrary, we did not observe a difference in survival when wild-type tumor cells were implanted in either IFNAR1 deficient or proficient hosts. Flow cytometry analysis will elucidate changes in immune cell recruitment and infiltration upon IFN signalling disruption. Moreover, we explore different treatments in combination with IFN-β as there are indications that TMZ or radiotherapy can have synergistic effects with stimulation of interferon type I signalling.

scholarly journals Revisiting the role of IRF3 in inflammation and immunity by conditional and specifically targeted gene ablation in mice

2018 ◽  
Vol 115 (20) ◽  
pp. 5253-5258 ◽  
Author(s):  
Hideyuki Yanai ◽  
Shiho Chiba ◽  
Sho Hangai ◽  
Kohei Kometani ◽  
Asuka Inoue ◽  
...  
Keyword(s):  
Immune Cell ◽  
Cell Types ◽  
Type I ◽  
Type I Ifn ◽  
Cell Type ◽  
Gene Ablation ◽  
Cell Type Specific

IFN regulatory factor 3 (IRF3) is a transcription regulator of cellular responses in many cell types that is known to be essential for innate immunity. To confirm IRF3’s broad role in immunity and to more fully discern its role in various cellular subsets, we engineered Irf3-floxed mice to allow for the cell type-specific ablation of Irf3. Analysis of these mice confirmed the general requirement of IRF3 for the evocation of type I IFN responses in vitro and in vivo. Furthermore, immune cell ontogeny and frequencies of immune cell types were unaffected when Irf3 was selectively inactivated in either T cells or B cells in the mice. Interestingly, in a model of lipopolysaccharide-induced septic shock, selective Irf3 deficiency in myeloid cells led to reduced levels of type I IFN in the sera and increased survival of these mice, indicating the myeloid-specific, pathogenic role of the Toll-like receptor 4–IRF3 type I IFN axis in this model of sepsis. Thus, Irf3-floxed mice can serve as useful tool for further exploring the cell type-specific functions of this transcription factor.

The Monoclonal Antibody nBT062 Conjugated to Cytotoxic Maytansinoids Has Potent and Selective Cytotoxicity against CD138 Positive Multiple Myeloma Cells in Vitro and in Vivo.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 1716-1716 ◽  
Author(s):  
Hiroshi Ikeda ◽  
Teru Hideshima ◽  
Robert J. Lutz ◽  
Sonia Vallet ◽  
Samantha Pozzi ◽  
...  
Keyword(s):  
Multiple Myeloma ◽  
Monoclonal Antibody ◽  
Tumor Cells ◽  
Cell Lines ◽  
Xenograft Model ◽  
Growth Delay ◽  
Selective Cytotoxicity ◽  
Bystander Killing

Abstract CD138 is expressed on differentiated plasma cells and is involved in the development and/or proliferation of multiple myeloma (MM), for which it is a primary diagnostic marker. In this study, we report that immunoconjugates comprised of the murine/human chimeric CD138-specific monoclonal antibody nBT062 conjugated with highly cytotoxic maytansinoid derivatives (nBT062-SMCC-DM1, nBT062-SPDB-DM4 and nBT062-SPP-DM1) showed cytotoxic activity against CD138-positive MM cells both in vitro and in vivo. These agents demonstrated cytotoxicity against OPM1 and RPMI8226 (CD138-positive MM cell lines) in a dose and time-dependent fashion and were also cytotoxic against primary tumor cells from MM patients. Minimal cytotoxicity was noted in CD138-negative cell lines and no activity was observed against peripheral blood mononuclear cells from healthy volunteers, suggesting that CD138-targeting is important for immunoconjugate-mediated cytotoxicity. Examination of the mechanism of action whereby these immunoconjugates induced cytotoxicity in MM cells demonstrated that treatment triggered G2/M cell cycle arrest, followed by apoptosis associated with cleavage of PARP and caspase-3, -8 and -9. Neither interleukin-6 nor insulin-like growth factor-I could overcome the apoptotic effect of these agents. The level of soluble (s)CD138 in the BM plasma from 15 MM patients was evaluated to determine the potential impact of sCD138 on immunoconjugate function. The sCD138 level in BM plasma was found to be significantly lower than that present in MM cell culture supernatants where potent in vitro cytotoxicity was observed, suggesting that sCD138 levels in MM patient BM plasma would not interfere with immunoconjugate activity. Because adhesion to bone marrow stromal cells (BMSCs) triggers cell adhesion mediated drug resistance to conventional therapies, we next examined the effects of the conjugates on MM cell growth in the context of BMSC. Co-culture of MM cells with BMSCs, which protects against dexamethasoneinduced death, had no impact on the cytotoxicity of the immunoconjugates. The in vivo efficacy of these immunoconjugates was also evaluated in SCID mice bearing established CD138-positive MM xenografts and in a SCID-human bone xenograft model of myeloma. Significant tumor growth delay or regressions were observed at immunoconjugate concentrations that were well tolerated in all models tested. The ability of these agents to mediate bystander killing of proximal CD138-negative cells was also evaluated. While nBT062-SPDB-DM4 was inactive against CD138-negative Namalwa cells cultured alone, significant killing of these CD138-negative cells by nBT062-SPDB-DM4 was observed when mixed with CD138-positive OPM2 cells. This bystander killing may contribute to the eradication of MM tumors by disrupting the tumor microenvironment and/or killing CD138-negative MM tumor cells, such as the putative CD138 negative myeloma stem cells. These studies demonstrate strong evidence of in vitro and in vivo selective cytotoxicity of these immunoconjugates and provide the preclinical framework supporting evaluation of nBT062-based immunoconjugates in clinical trials to improve patient outcome in MM.

scholarly journals Antibody-Based Targeting of Interferon-Beta-1a Mutein in HER2-Positive Cancer Enhances Antitumor Effects Through Immune Responses and Direct Cell Killing

2021 ◽  
Vol 11 ◽  
Author(s):  
Chan Gyu Lee ◽  
TaeEun Kim ◽  
Sungyoul Hong ◽  
Jongwan Chu ◽  
Ju Eun Kang ◽  
...  
Keyword(s):  
Tumor Targeting ◽  
Antitumor Effect ◽  
Immune Cell ◽  
Tumor Growth Inhibition ◽  
Type I ◽  
Biophysical Properties ◽  
Her2 Positive ◽  
Antitumor Effects ◽  
Direct Cell

Type I interferon (IFN) has been approved as an anticancer agent to treat some malignancies. However, IFNs have a short in vivo half-life, systemic toxicity, and poor biophysical properties, which prevent it from being widely used for cancer therapy. This study aimed to construct recombinant IFN-β-1a mutein immunocytokines that comprise a human epidermal growth factor receptor 2 (HER2)-targeting antibody and IFN-β muteins with an additional glycosylation, which can overcome the limitation of the cytokine itself. Hence, the molecular design aims to 1) enhance productivity and biophysical properties by adding secondary glycosylation in IFN-β, 2) increase the therapeutic index of IFN-β therapy by preferential retention at the tumor by possessing high affinity for HER2-expressing cancer cells, and 3) improve the pharmacokinetics and, thus, the convenience of IFN-β administration. The yield of trastuzumab-IFN-β mutein was higher than that of trastuzumab-wild-type IFN-β in the mammalian cell culture system. Trastuzumab-IFN-β mutein showed similar IFN activity and HER2-targeting ability equivalent to that of IFN-β mutein and trastuzumab, respectively. Trastuzumab-IFN-β mutein directly inhibited the growth of HER2-positive gastric cancer cell lines and was more effective than trastuzumab or IFN-β mutein alone. Trastuzumab-IFN-β mutein and IFN-β mutein displayed enhanced immune cell-mediated cytotoxicity. Collectively, trastuzumab-IFN-β mutein may have indirect immune cell-mediated antitumor effects and direct cell growth inhibitory effects. Tumor-targeting effect of trastuzumab-IFN-β mutein was analyzed using in vivo fluorescence imaging. The accumulation of trastuzumab-IFN-β mutein was observed in HER2-positive tumors rather than other tissues except the liver. To evaluate the both direct tumor growth inhibition effect and indirect immune cell-mediated antitumor effect, we tested the effect of trastuzumab-IFN-β mutein in HER2-positive cancer xenograft models using nude mice or humanized mice. Trastuzumab-IFN-β mutein could significantly enhance tumor regression when compared with trastuzumab or IFN-β mutein. In addition, an increase in tumor-infiltrating lymphocytes was observed in the trastuzumab-IFN-β mutein-treated group, implying that the tumor-targeting IFN-β may have an enhanced antitumor effect through increased immune response. Therefore, targeting IFN-β with an anti-HER2 monoclonal antibody makes the immunocytokine more potent than either agent alone. These novel findings suggest that trastuzumab-IFN-β mutein merits clinical evaluation as a new candidate of anticancer therapeutics.

scholarly journals Neuroinvasion of SARS-CoV-2 in human and mouse brain

2021 ◽  
Vol 218 (3) ◽  
Author(s):  
Eric Song ◽  
Ce Zhang ◽  
Benjamin Israelow ◽  
Alice Lu-Culligan ◽  
Alba Vieites Prado ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
Immune Cell ◽  
Multiple Organ ◽  
Type I ◽  
Organ Systems ◽  
The Central Nervous System ◽  
Interferon Responses ◽  
The Brain ◽  
Immune Cell Infiltrates

Although COVID-19 is considered to be primarily a respiratory disease, SARS-CoV-2 affects multiple organ systems including the central nervous system (CNS). Yet, there is no consensus on the consequences of CNS infections. Here, we used three independent approaches to probe the capacity of SARS-CoV-2 to infect the brain. First, using human brain organoids, we observed clear evidence of infection with accompanying metabolic changes in infected and neighboring neurons. However, no evidence for type I interferon responses was detected. We demonstrate that neuronal infection can be prevented by blocking ACE2 with antibodies or by administering cerebrospinal fluid from a COVID-19 patient. Second, using mice overexpressing human ACE2, we demonstrate SARS-CoV-2 neuroinvasion in vivo. Finally, in autopsies from patients who died of COVID-19, we detect SARS-CoV-2 in cortical neurons and note pathological features associated with infection with minimal immune cell infiltrates. These results provide evidence for the neuroinvasive capacity of SARS-CoV-2 and an unexpected consequence of direct infection of neurons by SARS-CoV-2.

scholarly journals Single-Domain Antibodies for Targeting, Detection, and In Vivo Imaging of Human CD4+ Cells

2021 ◽  
Vol 12 ◽  
Author(s):  
Bjoern Traenkle ◽  
Philipp D. Kaiser ◽  
Stefania Pezzana ◽  
Jennifer Richardson ◽  
Marius Gramlich ◽  
...  
Keyword(s):  
T Cell ◽  
Immune Cell ◽  
Inflammatory Diseases ◽  
Xenograft Model ◽  
Single Domain ◽  
Positron Emission ◽  
Depth Analysis ◽  
Single Domain Antibodies

The advancement of new immunotherapies necessitates appropriate probes to monitor the presence and distribution of distinct immune cell populations. Considering the key role of CD4+ cells in regulating immunological processes, we generated novel single-domain antibodies [nanobodies (Nbs)] that specifically recognize human CD4. After in-depth analysis of their binding properties, recognized epitopes, and effects on T-cell proliferation, activation, and cytokine release, we selected CD4-specific Nbs that did not interfere with crucial T-cell processes in vitro and converted them into immune tracers for noninvasive molecular imaging. By optical imaging, we demonstrated the ability of a high-affinity CD4-Nb to specifically visualize CD4+ cells in vivo using a xenograft model. Furthermore, quantitative high-resolution immune positron emission tomography (immunoPET)/MR of a human CD4 knock-in mouse model showed rapid accumulation of 64Cu-radiolabeled CD4-Nb1 in CD4+ T cell-rich tissues. We propose that the CD4-Nbs presented here could serve as versatile probes for stratifying patients and monitoring individual immune responses during personalized immunotherapy in both cancer and inflammatory diseases.

scholarly journals Ionizing radiation improves RIG-I mediated immunotherapy through enhanced p53 activation in malignant melanoma

2021 ◽  
Author(s):  
Silke Lambing ◽  
Stefan Holdenrieder ◽  
Patrick Müller ◽  
Christian Hagen ◽  
Stephan Garbe ◽  
...  
Keyword(s):  
Cell Death ◽  
Malignant Melanoma ◽  
Tumor Cell ◽  
Low Dose ◽  
Immune Cell ◽  
Cytotoxic T Cell ◽  
Great Promise ◽  
Type I ◽  
Tumor Cell Death

The activation of the innate immune receptor RIG-I is a promising approach in immunooncology and currently under investigation in clinical trials. RIG-I agonists elicit a strong immune activation in both tumor and immune cells and induce both direct and indirect immune cell-mediated tumor cell death which involves tumor-specific cytotoxic T-cell response and type I interferon-driven innate cytotoxic immunity. Besides RIG-I, irradiation is known to induce cytotoxic DNA damage resulting in tumor debulking followed by the induction of tumor-specific immunity. To date, it is unclear whether the molecular antitumor effects of RIG-I and irradiation are additive or even synergize. Here, we investigated the combination of RIG-I activation with radiotherapy in melanoma. We found that low dose x-ray irradiation enhanced the extent and immunogenicity of RIG-I mediated tumor cell death in human and murine melanoma cell lines and in the murine B16 melanoma model in vivo. Pathway analysis of transcriptomic data revealed a central role for p53 downstream of the combined treatment, which was corroborated using p53-/- B16 cells. In vivo, the additional effect of irradiation on immune cell activation and inhibition of tumor growth was lost in mice carrying p53-knockout B16 tumors, while the response to RIG-I stimulation in those mice was maintained. Thus, our results identify p53 as pivotal for the synergy of RIG-I with irradiation, resulting in potent induction of immunogenic tumor cell death. Consequently, low dose radiotherapy holds great promise to further improve the efficacy or RIG-I ligands especially in patients with malignant melanoma or other tumors exhibiting a functional p53 pathway.

scholarly journals Identification of Potent Paracaspase MALT1 Inhibitors for Hematological Malignancies

Blood ◽  
2020 ◽  
Vol 136 (Supplement 1) ◽  
pp. 30-30
Author(s):  
Wu Yin ◽  
Nie Zhe ◽  
Andrew Placzek ◽  
Michael Trzoss ◽  
Goran Krilov ◽  
...  
Keyword(s):  
B Cell ◽  
Cell Lymphoma ◽  
Synergistic Effects ◽  
Xenograft Model ◽  
B Cell Lymphoma ◽  
B Cell Lymphomas ◽  
Publicly Traded ◽  
Ongoing Work

Introduction: MALT1 (mucosa-associated lymphoid tissue lymphoma translocation protein 1), was identified as a translocation protein fused with cIAP2 in mucosa-associated lymphoid tissue (MALT) B cell lymphomas. MALT1, a key mediator of NF-κB signaling and the main driver of a subset of B-cell lymphomas, functions via formation of a complex with CARMA1 and BCL10 to mediate antigen receptor-induced lymphocyte activation. MALT1 has been considered as a potential therapeutic target for several non-Hodgkin B cell lymphomas as well as chronic lymphocytic leukemia (CLL). Here, we describe the discovery of novel, potent MALT1 inhibitors that result in antiproliferative effects in non-Hodgkin B-cell lymphoma cells. Results: We have identified novel small molecule MALT1 inhibitors using our proprietary physics-based Free Energy Perturbation (FEP+) modeling technology. Our compounds show potent (sub nM) inhibition of MALT1 enzymatic activity, as well as high binding affinity (sub nM) to MALT1 protein measured by Surface Plasmon Resonance (SPR). BCL10 is a binding partner of MALT1 that is cleaved by MALT1 at the C-terminus. Our inhibitors were efficacious in a target engagement assay showing prevention of BCL10 cleavage in Activated B-cell (ABC) subtype of diffuse large B cell lymphoma (DLBCL) cell lines OCI-LY3 and OCI-LY10, which are Bruton tyrosine kinase (BTK) inhibitor ibrutinib-resistant and -responsive respectively. Our compounds are potent inhibitors of IL10 secretion in both OCI-LY3 and OCI-LY10 cells, which is consistent with the inhibition of NF-κB signaling. We also examined the effect of our MALT1 inhibitors on ABC-DLBCL cell proliferation. Our inhibitors demonstrated potent anti-proliferative effects in both OCI-LY3 and OCI-LY10 cell lines, as well as synergistic effects with ibrutinib in a BTKi sensitive ABC-DLBCL cell panel. Examinations of a protease panel and off-target safety screening panel, as well as in vivo high dose tolerability study showed our compound had excellent selectivity and significant safety margin. Plasma IL10 and tumor BCL10 have been identified as robust PD markers in PK/PD studies in both OCI-LY3 and OCI-LY10 tumor bearing mice. Dose-dependent tumor growth inhibition was observed after 3 weeks of treatment in OCI-LY3 xenograft model, with efficacy also observed in combination with venetoclax. Ongoing work: We are continuing to explore the synergistic effects of our compounds with BTK inhibitors in B-cell lymphoma mouse models. Preliminary data showed potent inhibition of IL-2 secretion in Jurkat cells from our compound treatment. Additional studies are ongoing to elucidate the role of MALT1 inhibition in Treg as well as Teffector cells in vitro and in vivo. Refinement of the current inhibitor series, using co-crystal structures, is in progress in preparation for further development of optimized molecules. Conclusion and Future Plans: We have identified novel potent MALT1 protease small molecule inhibitors that are efficacious in the in vitro B-cell lymphoma cell proliferation assays and in the in vivo B-cell lymphoma xenograft model. Our data suggest that targeting MALT1 may expand therapy options for patients with selected B-cell lymphomas, such as ABC-DLBCL. Our work provided insight into the anti-tumor efficacy of our inhibitors in B-cell lymphomas as single agent, and ongoing work will continue to assess the potential combination with BTKi to overcome drug-induced resistance in patients with relapsed/refractory B-cell lymphoma. Disclosures Yin: Schrodinger: Current Employment, Current equity holder in publicly-traded company. Zhe:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Placzek:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Trzoss:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Krilov:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Feng:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Lawrenz:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Pelletier:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Lai:Triplet Therapeutics: Current Employment, Current equity holder in private company. Bell:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Calkins:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Grimes:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Tang:Schrodinger: Current Employment, Current equity holder in publicly-traded company. McRobb:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Gerasyuto:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Feher:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Mondal:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Jensen:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Wright:Schrodinger: Current Employment, Current equity holder in publicly-traded company. Akinsanya:Schrodinger: Current Employment, Current equity holder in publicly-traded company.

scholarly journals TMIC-12. TUMOR EDGE-DESTINED CELLS IN GBM CELLS IN A CELL-INTRINSIC MECHANISM

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi249-vi249
Author(s):  
Daisuke Yamashita ◽  
Mutsuko Minata ◽  
Hai Yu ◽  
Soujun Zhang ◽  
Chaoxi Li ◽  
...  
Keyword(s):  
Tumor Cells ◽  
Glioma Initiating Cells ◽  
Intrinsic Mechanism ◽  
Unfavorable Clinical Outcome ◽  
Current Therapies ◽  
A Cell ◽  
Cell Subpopulations ◽  
Tumor Edge

Abstract The highly infiltrative nature of glioblastoma (GBM) underscores limited response to current therapies and subsequent unfavorable clinical outcome. Despite the gross total resection of tumors located in the enhancing lesions, GBMs inevitably recur from the areas adjacent to the resection cavity that retains tumor cells with tumor-initiating capacity with therapy resistant nature (glioma-initiating cells: GICs). Here, we identified, in clinical GBM tumors, two mutually-exclusive glioma-initiating cell subpopulations in two different regions of GBM tumors, core- and edge-located glioma-initiating cells that co-exist in single tumors (Minata et al. Cell Reports. 2019). Following this observation, we further established patient-derived GBM clones from both tumor core and edge tissues, termed core-GICs and edge-GICs, and uncovered their distinct molecular signatures. Unexpectedly, we found that these two distinct GIC subpopulations retain the spatial identity, meaning that the core GICs locate themselves in the injected site, whereas the edge GICs initiated to form edge-like lesions, when xenografted into mouse brains. Through OMICs analyses, we identified CD38 as a key molecule to determine the edge phenotype both in vitro and in vivo. Collectively, our findings indicate, for the first time, that GBM cells are heterogeneous to be composed of tumor cells destined to be located in distinct regions of the tumors in a molecularly-defined manner.

scholarly journals SCIDOT-28. TARGETED NANOPARTICLES FOR IMPROVED DRUG DELIVERY TO MEDULLOBLASTOMA

2019 ◽  
Vol 21 (Supplement_6) ◽  
pp. vi277-vi277
Author(s):  
Joelle P Straehla ◽  
Natalie Boehnke ◽  
Tamara G Dacoba ◽  
Paula T Hammond
Keyword(s):  
Drug Delivery ◽  
Endothelial Cells ◽  
Side Effects ◽  
Tumor Cells ◽  
Chemical Engineering ◽  
Xenograft Model ◽  
In Vivo Studies ◽  
Layer By Layer

Abstract Platinum-based agents remain a key component of therapy for children with medulloblastoma, despite significant systemic side effects and only modest blood-brain barrier (BBB) penetration. Cisplatin has a cerebrospinal fluid-to-plasma ratio <5% and dose-limiting side effects of nephrotoxicity, ototoxicity, and myelosuppression. Improving delivery of cisplatin across the BBB and selectively accumulating in tumors could improve its therapeutic index. To this end, we are leveraging chemical engineering techniques to rationally design cisplatin nanoparticles (NPs) to cross the BBB and preferentially enter medulloblastoma tumor cells. Using the layer-by-layer (LbL) platform to ‘wrap’ polyelectrolytes around a NP core by iterative electrostatic adsorption, we screened six negatively charged polypeptide and polysaccharide outer layers in medulloblastoma cell lines. Poly-L-aspartic acid (PLD) layered NPs had significant accumulation in tumor cells after 24 hours incubation, with an uptake index of 18±4 over unlayered control NPs. Next, we generated propargyl-functionalized PLD and used click chemistry to covalently conjugate the BBB shuttle ligands glutathione, angiopep-2, and transferrin, which have been shown to mediate transcytosis across brain endothelial cells. PLD layered NPs functionalized with angiopep-2 and transferrin had enhanced uptake in medulloblastoma tumor cells and NPs functionalized with glutathione were non-inferior to PLD layered NPs. After incubation with endothelial cells in vitro, all three BBB shuttle ligands enhanced uptake of PLD layered NPs over unlayered and non-functionalized control NPs. We then incorporated cisplatin into the nanoparticle core of this platform. Cisplatin-loaded NPs with PLD layering and ligand functionalization were more effective than free cisplatin as measured by IC50 over 72 hours in culture, and led to faster apoptosis as assessed by flow cytometry with annexin V and propidium iodide staining. In summary, functionalized nanoparticles are a promising platform to modulate drug delivery to medulloblastoma. In vivo studies using an orthotopic xenograft model are underway to investigate biodistribution, efficacy, and toxicity.

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