Systemic Delivery of an Adjuvant CXCR4-CXCL12 Signaling Inhibitor Encapsulated in Synthetic Protein Nanoparticles for Glioma Immunotherapy

Glioblastoma (GBM) is an aggressive primary brain cancer, with a 5 year survival of ∼5%. Challenges that hamper GBM therapeutic efficacy include (i) tumor heterogeneity, (ii) treatment resistance, (iii) immunosuppressive tumor microenvironment (TME), and (iv) the blood-brain barrier (BBB). The C-X-C motif chemokine ligand-12/C-X-C motif chemokine receptor-4 (CXCL12/CXCR4) signaling pathway is activated in GBM and is associated with tumor progression. Although the CXCR4 antagonist (AMD3100) has been proposed as an attractive anti-GBM therapeutic target, it has poor pharmacokinetic properties, and unfavorable bioavailability has hampered its clinical implementation. Thus, we developed synthetic protein nanoparticles (SPNPs) coated with the transcytotic peptide iRGD (AMD3100-SPNPs) to target the CXCL2/CXCR4 pathway in GBM via systemic delivery. We showed that AMD3100-SPNPs block CXCL12/CXCR4 signaling in three mouse and human GBM cell cultures in vitro and in a GBM mouse model in vivo. This results in (i) inhibition of GBM proliferation, (ii) reduced infiltration of CXCR4+ monocytic myeloid-derived suppressor cells (M-MDSCs) into the TME, (iii) restoration of BBB integrity, and (iv) induction of immunogenic cell death (ICD), sensitizing the tumor to radiotherapy and leading to anti-GBM immunity. Additionally, we showed that combining AMD3100-SPNPs with radiation led to long-term survival, with ∼60% of GBM tumor-bearing mice remaining tumor free after rechallenging with a second GBM in the contralateral hemisphere. This was due to a sustained anti-GBM immunological memory response that prevented tumor recurrence without additional treatment. In view of the potent ICD induction and reprogrammed tumor microenvironment, this SPNP-mediated strategy has a significant clinical translation applicability.Fil: Alghamri, Mahmoud S.. University Of Michigan Medical School; Estados UnidosFil: Banerjee, Kaushik. University Of Michigan Medical School; Estados UnidosFil: Mujeeb, Anzar A.. University Of Michigan Medical School; Estados UnidosFil: Mauser, Ava. University of Michigan; Estados UnidosFil: Taher, Ayman. University Of Michigan Medical School; Estados UnidosFil: Thalla, Rohit. University Of Michigan Medical School; Estados UnidosFil: McClellan, Brandon L.. University Of Michigan Medical School; Estados UnidosFil: Varela, Maria L.. University Of Michigan Medical School; Estados UnidosFil: Stamatovic, Svetlana M.. University Of Michigan Medical School; Estados UnidosFil: Martinez Revollar, Gabriela. University Of Michigan Medical School; Estados UnidosFil: Andjelkovic, Anuska V.. University Of Michigan Medical School; Estados UnidosFil: Gregory, Jason V.. University of Michigan; Estados UnidosFil: Kadiyala, Padma. University Of Michigan Medical School; Estados UnidosFil: Calinescu, Alexandra. University Of Michigan Medical School; Estados UnidosFil: Jiménez, Jennifer A.. University of Michigan; Estados UnidosFil: Apfelbaum, April A.. University of Michigan; Estados UnidosFil: Lawlor, Elizabeth R.. University of Washington; Estados UnidosFil: Carney, Stephen. University of Michigan; Estados UnidosFil: Comba, Andrea. University Of Michigan Medical School; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Faisal, Syed Mohd. University Of Michigan Medical School; Estados UnidosFil: Barissi, Marcus. University Of Michigan Medical School; Estados UnidosFil: Edwards, Marta B.. University Of Michigan Medical School; Estados UnidosFil: Appelman, Henry. University Of Michigan Medical School; Estados UnidosFil: Sun, Yilun. Case Western Reserve University; Estados UnidosFil: Gan, Jingyao. University of Michigan; Estados UnidosFil: Ackermann, Rose. University of Michigan; Estados UnidosFil: Schwendeman, Anna. University of Michigan; Estados UnidosFil: Candolfi, Marianela. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones Biomédicas; ArgentinaFil: Olin, Michael R.. University of Minnesota; Estados UnidosFil: Lahann, Joerg. University of Michigan; Estados UnidosFil: Lowenstein, Pedro R.. University of Michigan; Estados UnidosFil: Castro, Maria G.. University of Michigan; Estados Unido

The Epstein-Barr Virus Immediate-Early Protein BZLF1 Induces both a G(2) and a Mitotic Block

The Epstein-Barr virus immediate-early protein BZLF1 is a transcriptional activator that mediates the switch from latent to lytic infection. Here we demonstrate that BZLF1 induces both a G(2) block and a mitotic block in HeLa cells and inhibits chromosome condensation. While the G(2) block is associated with decreased cyclin B1 in host cells and can be rescued by overexpression of cyclin B1, the mechanism for the mitotic defect is as yet undetermined

Epstein-Barr Virus Immediate-Early Proteins BZLF1 and BRLF1 Activate the ATF2 Transcription Factor by Increasing the Levels of Phosphorylated p38 and c-Jun N-Terminal Kinases

Expression of either Epstein-Barr virus (EBV) immediate-early protein BZLF1 (Z) or BRLF1 (R) is sufficient to convert EBV infection from the latent to lytic form. Disruption of viral latency requires transcriptional activation of the Z and R promoters. The Z and R proteins are transcriptional activators, and each immediate-early protein activates expression of the other immediate-early protein. Z activates the R promoter through a direct binding mechanism. However, R does not bind directly to the Z promoter. In this study, we demonstrate that the ZII element (a cyclic AMP response element site) in the Z promoter is required for efficient activation by R. The ZII element has been shown to be important for induction of lytic EBV infection by tetradecanoyl phorbol acetate and surface immunoglobulin cross-linking and is activated by Z through an indirect mechanism. We demonstrate that both R and Z activate the cellular stress mitogen-activated protein (MAP) kinases, p38 and JNK, resulting in phosphorylation (and activation) of the cellular transcription factor ATF2. Furthermore, we show that the ability of R to induce lytic EBV infection in latently infected cells is significantly reduced by inhibition of either the p38 kinase or JNK pathways. In contrast, inhibition of stress MAP kinase pathways does not impair the ability of Z expression vectors to disrupt viral latency, presumably because expression of Z under the control of a strong heterologous promoter bypasses the need to activate Z transcription. Thus, both R and Z can activate the Z promoter indirectly by inducing ATF2 phosphorylation, and this activity appears to be important for R-induced disruption of viral latency

Natalizumab plus interferon beta-1a reduces lesion formation in relapsing multiple sclerosis

The SENTINEL study showed that the addition of natalizumab improved outcomes for patients with relapsing multiple sclerosis (MS)who had experienced disease activitywhile receiving interferon beta-1a (IFNβ-1a) alone. Previously unreported secondary and tertiary magnetic resonance imaging (MRI) measures are presented here. Patients received natalizumab 300 mg (n=589) or placebo (n=582) intravenously every 4 weeks plus IFNβ-1a 30 μg intramuscularly once weekly. Annual MRI scans allowed comparison of a range of MRI end points versus baseline. Over 2 years, 67% of patients receiving natalizumab plus IFNβ-1a remained free of newor enlarging T2- lesions compared with 30% of patients receiving IFNβ-1a alone. The mean change from baseline in T2 lesion volume over 2 years decreased in patients receiving natalizumab plus IFNβ-1a and increased in those receiving IFNβ-1a alone (–277.5 mm3 versus 525.6 mm3; pb0.001). Compared with IFNβ-1a alone, add-on natalizumab therapy resulted in a smaller increase in mean T1-hypointense lesion volume after 2 years (1821.3 mm3 versus 2210.5mm3; pb0.001), a smaller mean number of new T1-hypointense lesions over 2 years (2.3 versus 4.1; pb0.001), and a slower rate of brain atrophy during the second year of therapy (–0.31% versus –0.40%; p=0.020). Natalizumab add-on therapy reduced gadolinium-enhancing, T1-hypointense, and T2 MRI lesion activity and slowed brain atrophy progression in patients with relapsing MS who experienced disease activity despite treatment with IFNβ-1a alon