Soft tissue sarcoma.

Gene therapy mediated by recombinant adeno-associated virus (AAV) vectors is a promising treatment for systemic monogenic diseases. However, vector immunogenicity represents a major limitation to gene transfer with AAV vectors, particularly for vector re-administration. Here, we demonstrate that synthetic vaccine particles encapsulating rapamycin (SVP[Rapa]), co-administered with AAV vectors, prevents the induction of anti-capsid humoral and cell-mediated responses. This allows successful vector re-administration in mice and nonhuman primates. SVP[Rapa] dosed with AAV vectors reduces B and T cell activation in an antigen-selective manner, inhibits CD8+ T cell infiltration in the liver, and efficiently blocks memory T cell responses. SVP[Rapa] immunomodulatory effects can be transferred from treated to naive mice by adoptive transfer of splenocytes, and is inhibited by depletion of CD25+ T cells, suggesting a role for regulatory T cells. Co-administration of SVP[Rapa] with AAV vector represents a powerful strategy to modulate vector immunogenicity and enable effective vector re-administration.

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Antigen-selective modulation of AAV immunogenicity with tolerogenic rapamycin nanoparticles enables successful vector re-administration

Peptides have emerged as important therapeutics that are being rigorously tested in angiogenesis-dependent diseases due to their low toxicity and high specificity. Since the discovery of endogenous proteins and protein fragments that inhibit microvessel formation (thrombospondin, endostatin) several peptides have shown promise in pre-clinical and clinical studies for cancer. Peptides have been derived from thrombospondin, collagens, chemokines, coagulation cascade proteins, growth factors, and other classes of proteins and target different receptors. Here we survey recent developments for anti-angiogenic peptides with length not exceeding 50 amino acid residues that have shown activity in pre-clinical models of cancer or have been tested in clinical trials; some of the peptides have been modified and optimized, e.g., through L-to-D and non-natural amino acid substitutions. We highlight technological advances in peptide discovery and optimization including computational and bioinformatics tools and novel experimental techniques.

Anti-angiogenic peptides for cancer therapeutics

SUMMARY
AAV-based gene transfer protocols have shown remarkable success when directed to immune-privileged sites such as for retinal disorders like Lebers congenital amaurosis. In contrast, AAV-mediated gene transfer into liver or muscle tissue for diseases such as hemophilia B, α1 anti-trypsin deficiency and muscular dystrophy has demonstrated a decline in gene transfer efficacy over time. It is now known that in humans, AAV triggers specific pathways that recruit immune sensors. These factors initiate an immediate reaction against either the viral capsid or the vector encoded protein as part of innate immune response or to produce a more specific adaptive response that generates immunological memory. The vector-transduced cells are then rapidly destroyed due to this immune activation. However, unlike other viral vectors, AAV is not immunogenic in murine models. Its immunogenicity becomes apparent only in large animal models and human subjects. Moreover, humans are natural hosts to AAV and exhibit a high seroprevalence against AAV vectors. This limits the widespread application of AAV vectors into patients with pre-existing neutralising antibodies or memory T cells. To address these issues, various strategies are being tested. Alternate serotype vectors (AAV1-10), efficient expression cassettes, specific tissue targeting, immune-suppression and engineered capsid variants are some approaches proposed to minimise this immune stimulation. In this review, we have summarised the nature of the immune response documented against AAV in various pre-clinical and clinical settings and have further discussed the strategies to evade them. Copyright © 2013 John Wiley & Sons, Ltd.

Adeno-associated virus (AAV) vectors in gene therapy: immune challenges and strategies to circumvent them

Adeno-associated virus (AAV) vectors are a platform of choice for in vivo gene transfer applications. However, neutralizing antibodies (NAb) to AAV can be found in humans and some animal species as a result of exposure to the wild-type virus, and high-titer NAb develop following AAV vector administration. In some conditions, anti-AAV NAb can block transduction with AAV vectors even when present at low titers, thus requiring prescreening before vector administration. Here we describe an improved in vitro, cell-based assay for the determination of NAb titer in serum or plasma samples. The assay is easy to setup and sensitive and, depending on the purpose, can be validated to support clinical development of gene therapy products based on AAV vectors.

Determination of anti-adeno-associated virus vector neutralizing antibody titer with an in vitro reporter system.

The purpose of this paper is to determine the efficacy of combining radiation therapy with endostar, a recombined humanized endostatin, in human nasopharyngeal carcinoma and human lung adenocarcinoma xenografts. Tumor xenografts were established in the hind limb of male athymic nude mice (BALB/c-nu) by subcutaneous transplantation. The tumor-bearing mice were assigned into four treatment groups: sham therapy (control), endostar (20 mg/kg, once daily for 10 days), radiation therapy (6 Gray per day to 30 Gray, once a day for 1 week), and endostar plus radiation therapy (combination). The experiment was repeated and mice were killed at days 3, 6, and 10 after initiation therapy, and the tumor tissues and blood samples were collected to analyze the kinetics of antitumor, antiangiogenesis, and antivascularization responses of different therapies. In human nasopharyngeal carcinoma and human lung adenocarcinoma xenografts, endostar significantly enhanced the effects of tumor growth inhibition, endothelial cell and tumor cell apoptosis induction, and improved tumor cell hypoxia of radiation therapy. Histological analyses demonstrated that endostar plus radiation also induced a significant reduction in microvascular density, microvascular area, and vascular endothelial growth factor and matrix metalloproteinase-2 expression compared with radiation and endostar alone respectively. We concluded that endostar significantly sensitized the function of radiation in antitumor and antiangiogenesis in human nasopharyngeal carcinoma and human lung adenocarcinoma xenografts by increasing the apoptosis of the endothelial cell and tumor cell, improving the hypoxia of the tumor cell, and changing the proangiogenic factors. These data provided a rational basis for clinical practice of this multimodality therapy.

Endostar, a recombined humanized endostatin, enhances the radioresponse for human nasopharyngeal carcinoma and human lung adenocarcinoma xenografts in mice.

This study was conducted to evaluate the effectiveness and safety of intensity-modulated radiotherapy (IMRT) and concurrent paclitaxel plus cisplatin (TP regimen) for upper esophageal carcinoma. 36 patients of upper esophageal carcinoma were retrospectively analyzed. Patients were treated with IMRT (median 60 Gy) combined with concurrent TP regimen chemotherapy. The Kaplan-Meier analysis was performed in statistical analysis. Toxicities were recorded according to the NCI CTC version 3.0. 36 patients aged 43–73 years (median 57 years). The median follow-up period was 14.0 months. The 1-year and 2-year survival rates were 83.3% and 42.8% respectively. The median progression-free survival (PFS) time and overall survival (OS) time were 12.0 (95% CI: 7.8–16.2 months) and 18.0 months (95% CI: 9.9–26.1 months), respectively. Grade 3 neutropenia, radiation-induced esophagitis and radiodermatitis were observed in 5 (13.9%), 3 (8.3%) and 8 (22.2%) patients respectively. There were two treatment-related deaths due to esophageal perforation and hemorrhea. For those patients with upper esophageal carcinoma, IMRT combined with concurrent TP regimen chemotherapy was an effective treatment. However, more attention should be paid to the occurrence of perforation and hemorrhea.

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Paclitaxel and cisplatin combined with intensity-modulated radiotherapy for upper esophageal carcinoma

Assessment of a passive immunity mouse model to quantitatively analyze the impact of neutralizing antibodies on adeno-associated virus-mediated gene transfer

Paclitaxel and Cisplatin Combined with Intensity-Modulated Radiotherapy for Upper Esophageal Carcinoma

A 36-year-old woman had presented with dry cough for 2 months. Thoracic computed tomography (CT) scan showed a 12 cm × 8 cm ×5 cm mass in the anterior mediastinum. Due to intimately involving the aortic arch, tumor was removed incompletely. Residual tumor remained approximate 2 cm × 3 cm × 4 cm. Histologic diagnosis was a mature cystic teratoma containing a carcinoid. Subsequently, radiotherapy (RT) was administrated on residual tumor for a total dose of 50 Gy at 2 Gy/d fraction in 25 fractions. At 2-year follow-up, the patient had stable disease. In conclusion, adjuvant radiotherapy with 50 Gy is an effective approach for residual tumor of mediastinal carcinoid teratoma.

Lingli Tu

Papers

Endostar, a recombined humanized endostatin, enhances the radioresponse for human nasopharyngeal carcinoma and human lung adenocarcinoma xenografts in mice.

Paclitaxel and cisplatin combined with intensity-modulated radiotherapy for upper esophageal carcinoma

Assessment of a passive immunity mouse model to quantitatively analyze the impact of neutralizing antibodies on adeno-associated virus-mediated gene transfer

Paclitaxel and Cisplatin Combined with Intensity-Modulated Radiotherapy for Upper Esophageal Carcinoma

Postoperative radiotherapy for residual tumor of primary mediastinal carcinoid teratoma