The stimulation of the immune system using oncolytic adenoviruses (OAds) has attracted significant interest and several studies suggested that OAds immunogenicity might be important for their efficacy. Therefore, we developed a versatile and rapid system to adsorb tumor-specific major histocompatibility complex class I (MHC-I) peptides onto the viral surface to drive the immune response toward the tumor epitopes. By studying the model epitope SIINFEKL, we demonstrated that the peptide-coated OAd (PeptiCRAd) retains its infectivity and the cross presentation of the modified-exogenous epitope on MHC-I is not hindered. We then showed that the SIINFEKL-targeting PeptiCRAd achieves a superior antitumor efficacy and increases the percentage of antitumor CD8+ T cells and mature epitope-specific dendritic cells in vivo. PeptiCRAds loaded with clinically relevant tumor epitopes derived from tyrosinase-related protein 2 (TRP-2) and human gp100 could reduce the growth of primary-treated tumors and secondary-untreated melanomas, promoting the expansion of antigen-specific T-cell populations. Finally, we tested PeptiCRAd in humanized mice bearing human melanomas. In this model, a PeptiCRAd targeting the human melanoma-associated antigen A1 (MAGE-A1) and expressing granulocyte and macrophage colony-stimulating factor (GM-CSF) was able to eradicate established tumors and increased the human MAGE-A1-specific CD8+ T cell population. Herein, we show that the immunogenicity of OAds plays a key role in their efficacy and it can be exploited to direct the immune response system toward exogenous tumor epitopes. This versatile and rapid system overcomes the immunodominance of the virus and elicits a tumor-specific immune response, making PeptiCRAd a promising approach for clinical testing.

Oncolytic viruses are able to specifically replicate, infect, and kill only cancer cells. Their combination with chemotherapeutic drugs has shown promising results due to the synergistic action of virus and drugs; the combinatorial therapy is considered a potential clinically relevant approach for cancer. In this study, we optimized a strategy to absorb peptides on the viral capsid, based on electrostatic interaction, and used this strategy to deliver an active antitumor drug. We used L-carnosine, a naturally occurring histidine dipeptide with a significant antiproliferative activity. An ad hoc modified, positively charged L-carnosine was combined with the capsid of an oncolytic adenovirus to generate an electrostatic virus-carnosine complex. This complex showed enhanced antitumor efficacy in vitro and in vivo in different tumor models. In HCT-116 colorectal and A549 lung cancer cell lines, the complex showed higher transduction ratio and infectious titer compared with an uncoated oncolytic adenovirus. The in vivo efficacy of the complex was tested in lung and colon cancer xenograft models, showing a significant reduction in tumor growth. Importantly, we investigated the molecular mechanisms underlying the effects of complex on tumor growth reduction. We found that complex induces apoptosis in both cell lines, by using two different mechanisms, enhancing viral replication and affecting the expression of Hsp27. Our system could be used in future studies also for delivery of other bioactive drugs. Mol Cancer Ther; 15(4); 651-60. Ó2016 AACR.

In oncolytic virotherapy, the ability of the virus to activate the immune system is a key attribute with regard to long-term antitumor effects. Vaccinia viruses bear one of the strongest oncolytic activities among all oncolytic viruses. However, its capacity for stimulation of antitumor immunity is not optimal, mainly due to its immunosuppressive nature. To overcome this problem, we developed an oncolytic VV that expresses intracellular pattern recognition receptor DNA-dependent activator of IFN-regulatory factors (DAI) to boost the innate immune system and to activate adaptive immune cells in the tumor. We showed that infection with DAI-expressing VV increases expression of several genes related to important immunological pathways. Treatment with DAI-armed VV resulted in significant reduction in the size of syngeneic melanoma tumors in mice. When the mice were rechallenged with the same tumor, DAI-VV-treated mice completely rejected growth of the new tumor, which indicates immunity established against the tumor. We also showed enhanced control of growth of human melanoma tumors and elevated levels of human T-cells in DAI-VV-treated mice humanized with human peripheral blood mononuclear cells. We conclude that expression of DAI by an oncolytic VV is a promising way to amplify the vaccine potency of an oncolytic vaccinia virus to trigger the innate—and eventually the long-lasting adaptive immunity against cancer.

BackgroundSensorineural hearing impairment is a common pathological manifestation in patients affected by X-linked intellectual disability. A few cases of interstitial deletions at Xq21 with several different phenotypic characteristics have been described, but to date, a complete molecular characterization of the deletions harboring disease-causing genes is still missing. Thus, the aim of this study is to realize a detailed clinical and molecular analysis of a family affected by syndromic X-linked hearing loss with intellectual disability.ResultsClinical analyses revealed a very complex phenotype that included inner ear malformations, vestibular problems, choroideremia and hypotonia with a peculiar pattern of phenotypic variability. Genomic analysis revealed, for the first time, the presence of two close interstitial deletions in the Xq21.1-21.3, harboring 11 protein coding, 9 non-coding genes and 19 pseudogenes. Among these, 3 protein coding genes have already been associated with X-linked hearing loss, intellectual disability and choroideremia.ConclusionsIn this study we highlighted the presence of peculiar genotypic and phenotypic details in a family affected by syndromic X-linked hearing loss with intellectual disability. We identified two, previously unreported, Xq21.1-21.3 interstitial deletions. The two rearrangements, containing several genes, segregate with the clinical features, suggesting their role in the pathogenicity. However, not all the observed phenotypic features can be clearly associated with the known genes thus, further study is necessary to determine regions involved.Electronic supplementary materialThe online version of this article (doi:10.1186/s13039-015-0120-0) contains supplementary material, which is available to authorized users.

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