Synergism of dual AAV gene therapy and rapamycin rescues GSDIII phenotype in muscle and liver.

Glycogen storage disease type III (GSDIII) is a rare metabolic disorder due to glycogen debranching enzyme (GDE) deficiency. Reduced GDE activity leads to pathological glycogen accumulation responsible for impaired hepatic metabolism and muscle weakness. To date, there is no curative treatment for GSDIII. We previously reported that 2 distinct dual AAV vectors encoding for GDE were needed to correct liver and muscle in a GSDIII mouse model. Here, we evaluated the efficacy of rapamycin in combination with AAV gene therapy. Simultaneous treatment with rapamycin and a potentially novel dual AAV vector expressing GDE in the liver and muscle resulted in a synergic effect demonstrated at biochemical and functional levels. Transcriptomic analysis confirmed synergy and suggested a putative mechanism based on the correction of lysosomal impairment. In GSDIII mice livers, dual AAV gene therapy combined with rapamycin reduced the effect of the immune response to AAV observed in this disease model. These data provide proof of concept of an approach exploiting the combination of gene therapy and rapamycin to improve efficacy and safety and to support clinical translation.

Liposomes as tunable platform to decipher the antitumor immune response triggered by TLR and NLR agonists.

Liposomes are powerful tools for the optimization of peptides and adjuvant composition in cancer vaccines. Here, we take advantage of a liposomal platform versatility to develop three vaccine candidates associating a peptide from HA influenza virus protein as CD4 epitope, a peptide from HPV16 E7 oncoprotein as CD8 epitope and TLR4, TLR2/6 or NOD1 agonists as adjuvant. Liposomal vaccine containing MPLA (TLR4 liposomes), are the most effective treatment against the HPV-transformed orthotopic lung tumor mouse model, TC-1. This vaccine induces a potent Th1-oriented antitumor immunity, which leads to a significant reduction in tumor growth and a prolonged survival of mice, even when injected after tumor appearance. This efficacy is dependent on CD8+ T cells. Subcutaneous injection of this treatment induces the migration of skin DCs to draining lymph nodes. Interestingly, TLR2/6 liposomes trigger a weaker Th1-immune response which is not sufficient for the induction of a prolonged antitumor activity. Although NOD1 liposome treatment results in the control of early tumor growth, it does not extend mice survival. Surprisingly, the antitumor activity of NOD1 vaccine is not associated with a specific adaptive immune response. This study shows that our modulable platform can be used for the strategical development of vaccines.

Optimization of peptide-based cancer vaccine compositions, by sequential screening, using versatile liposomal platform.

Therapeutic cancer vaccines need thoughtful design to efficiently deliver appropriate antigens and adjuvants to the immune system. In the current study, we took advantage of the versatility of a liposomal platform to conceive and customize vaccines containing three elements needed for the induction of efficient antitumor immunity: i) a CD4 epitope peptide able to activate CD4+ T helper cells, ii) a CD8 tumor-specific epitope peptide recognized by CD8+ T cytotoxic cells and iii) Pattern Recognition Receptor (PRR) agonists which stand as adjuvants. Each type of component, conjugated to liposomes, was evaluated individually by comparing their vaccine efficacy after immunization of naïve mice. These screening steps resulted in the optimization of three liposomal constructs bearing a peptide from HA influenza virus protein as CD4 epitope, a peptide from HPV16 E7 oncoprotein as CD8 epitope and TLR4, TLR2/6 or NOD1 agonists as adjuvant, which displayed antitumor efficiency against a mouse model of disseminated tumors transformed by HPV16. Our results validated the interest of our customizable liposomal platform as delivery system for cancer vaccination. We also demonstrated its interest as tool for vaccine design allowing the strategical selection of components, and the evaluation of epitope-adjuvant association.

Enhancing tumor specific immune responses by transcutaneous vaccination.

INTRODUCTION: Our understanding of the involvement of the immune system in cancer control has increased over recent years. However, the development of cancer vaccines intended to reverse tumor-induced immune tolerance remains slow as most current vaccine candidates exhibit limited clinical efficacy. The skin is particularly rich with multiple subsets of dendritic cells (DCs) that are involved to varying degrees in the induction of robust immune responses. Transcutaneous administration of cancer vaccines may therefore harness the immune potential of these DCs, however, this approach is hampered by the impermeability of the stratum corneum. Innovative vaccine formulations including various nanoparticles, such as liposomes, are therefore needed to properly deliver cancer vaccine components to skin DCs. Areas covered: The recent insights into skin DC subsets and their functional specialization, the potential of nanoparticle-based vaccines in transcutaneous cancer vaccination and, finally, the most relevant clinical trial advances in liposomal and in cutaneous cancer vaccines will be discussed. Expert commentary: To define the optimal conditions for mounting protective skin DC-induced anti-tumor immune responses, investigation of the cellular and molecular interplay that controls tumor progression should be pursued in parallel with clinical development. The resulting knowledge will then be translated into improved cancer vaccines that better target the most appropriate immune players.

Cutaneous leishmaniasis in the central provinces of Hama and Edlib in Syria: Vector identification and parasite typing.

BACKGROUND: Cutaneous leishmaniasis is a disease transmitted by sand fly bites. This disease is highly prevalent in Syria where Leishmania major and Leishmania tropica are the known aetiological agents. In 2011, more than 58,000 cases were reported in the country by the Ministry of Health. The central region of the country harbors 20 % of the reported cases. However, the epidemiology of the disease in this area is not well understood. An epidemiological survey was conducted in 2010 to identity the circulating parasite and the sand fly vector in the central provinces of Edlib and Hama. METHODS: Sand fly specimens were collected using CDC light traps and identified morphologically. Total DNA was extracted from the abdomens of female specimens and from Giemsa-stained skin lesion smears of 80 patients. Leishmania parasites were first identified by sequencing the ITS1 gene amplicons. Then polymorphism analysis was performed using the RFLP technique. RESULTS: A total of 2142 sand flies were collected. They belonged to eight species, among which Phlebotomus sergenti and Phlebotomus papatasi were the most predominant. L. tropica ITS1 gene was amplified from two pools of P. sergenti specimens and from skin smears of cutaneous leishmaniasis patients. This suggests that P. sergenti is the potential vector species in the study area. The digestion profiles of the obtained amplicons by TaqI restriction enzyme were identical for all analysed L. tropica parasites. Moreover, L. infantum ITS1 gene was amplified from two pools of Phlebotomus tobbi in the relatively humid zone of Edlib. CONCLUSIONS: L. tropica is confirmed to be the aetiological agent of cutaneous leishmaniasis cases in the central provinces. RFLP technique failed to show any genetic heterogeneity in the ITS1 gene among the tested parasites. The molecular detection of this parasite in human skin smears and in P. sergenti supports the vector status of this species in the study area. The detection of L. infantum in P. tobbi specimens indicates a potential circulation of this parasite in the humid zone of Edlib. Further epidemiological studies are needed to evaluate the burden of this visceral parasite in the study region.