Lm-LLO-Based Immunotherapies and HPV-Associated Disease

HPV infection is a direct cause of neoplasia and malignancy. Cellular immunologic activity against cells expressing HPV E6 and E7 is sufficient to eliminate the presence of dysplastic or neoplastic tissue driven by HPV infection. Live attenuated Listeria monocytogenes- (Lm-) based immunotherapy (ADXS11-001) has been developed for the treatment of HPV-associated diseases. ADXS11-001 secretes an antigen-adjuvant fusion (Lm-LLO) protein consisting of a truncated fragment of the Lm protein listeriolysin O (LLO) fused to HPV-16 E7. In preclinical models, this construct has been found to stimulate immune responses and affect therapeutic outcome. ADXS11-001 is currently being evaluated in Phase 2 clinical trials for cervical intraepithelial neoplasia, cervical cancer, and HPV-positive head and neck cancer. The use of a live attenuated bacterium is a more complex and complete method of cancer immunotherapy, as over millennia Lm has evolved to infect humans and humans have evolved to prevent and reject this infection over millennia. This evolution has resulted in profound pathogen-associated immune mechanisms which are genetically conserved, highly efficacious, resistant to tolerance, and can be uniquely invoked using this novel platform technology

Anti-PD-1 antibody significantly increases therapeutic efficacy of Listeria monocytogenes (Lm)-LLO immunotherapy

This work was supported by the Intramural Research Program of the Center for Cancer Research, NCI, NIH, Georgia Regents University Cancer Center (GRUCC) and Advaxis Inc. RAE is supported by a Fellowship Grant from King Hussein Institute for Biotechnology and Cancer (KHIBC, Jordan).Peer reviewedPublisher PD

A One Health overview, facilitating advances in comparative medicine and translational research.

Table of contentsA1 One health advances and successes in comparative medicine and translational researchCheryl StroudA2 Dendritic cell-targeted gorilla adenoviral vector for cancer vaccination for canine melanomaIgor Dmitriev, Elena Kashentseva, Jeffrey N. Bryan, David T. CurielA3 Viroimmunotherapy for malignant melanoma in the companion dog modelJeffrey N. Bryan, David Curiel, Igor Dmitriev, Elena Kashentseva, Hans Rindt, Carol Reinero, Carolyn J. HenryA4 Of mice and men (and dogs!): development of a commercially licensed xenogeneic DNA vaccine for companion animals with malignant melanomaPhilip J. BergmanA5 Successful immunotherapy with a recombinant HER2-expressing Listeria monocytogenes in dogs with spontaneous osteosarcoma paves the way for advances in pediatric osteosarcomaNicola J. Mason, Josephine S. Gnanandarajah, Julie B. Engiles, Falon Gray, Danielle Laughlin, Anita Gaurnier-Hausser, Anu Wallecha, Margie Huebner, Yvonne PatersonA6 Human clinical development of ADXS-HER2Daniel O'ConnorA7 Leveraging use of data for both human and veterinary benefitLaura S. TremlA8 Biologic replacement of the knee: innovations and early clinical resultsJames P. StannardA9 Mizzou BioJoint Center: a translational success storyJames L. CookA10 University and industry translational partnership: from the lab to commercializationMarc JacobsA11 Beyond docking: an evolutionarily guided OneHealth approach to drug discoveryGerald J. Wyckoff, Lee Likins, Ubadah Sabbagh, Andrew SkaffA12 Challenges and opportunities for data applications in animal health: from precision medicine to precision husbandryAmado S. GuloyA13 A cloud-based programmable platform for healthHarlen D. HaysA14 Comparative oncology: One Health in actionAmy K. LeBlancA15 Companion animal diseases bridge the translational gap for human neurodegenerative diseaseJoan R. Coates, Martin L. Katz, Leslie A. Lyons, Gayle C. Johnson, Gary S. Johnson, Dennis P. O'BrienA16 Duchenne muscular dystrophy gene therapyDongsheng DuanA17 Polycystic kidney disease: cellular mechanisms to emerging therapiesJames P. CalvetA18 The domestic cat as a large animal model for polycystic kidney diseaseLeslie A. Lyons, Barbara GandolfiA19 The support of basic and clinical research by the Polycystic Kidney Disease FoundationDavid A. BaronA20 Using naturally occurring large animal models of human disease to enable clinical translation: treatment of arthritis using autologous stromal vascular fraction in dogsMark L. WeissA21 Regulatory requirements regarding clinical use of human cells, tissues, and tissue-based productsDebra A. WebsterA22 Regenerative medicine approaches to Type 1 diabetes treatmentFrancis N. KaranuA23 The zoobiquity of canine diabetes mellitus, man's best friend is a friend indeed-islet transplantationEdward J. RobbA24 One Medicine: a development model for cellular therapy of diabetesRobert J. Harman

Androgen ablation augments human HLA2.1-restricted T cell responses to PSA self-antigen in transgenic mice

BACKGROUND In recent years, there has been an increasing interest in targeting human prostate tumor-associated antigens (TAAs) for prostate cancer immunotherapy as an alternative to other therapeutic modalities. However, immunologic tolerance to TAA poses a significant obstacle to effective, TAA-targeted immunotherapy. We sought to investigate whether androgen deprivation would result in circumventing immune tolerance to prostate TAA by impacting CD8 cell responses. METHODS To this end, we generated a transgenic mouse that expresses the human prostate-specific antigen (PSA) specifically in the prostate, and crossed it to the HLA-A2.1 transgenic mouse to evaluate how androgen deprivation affects human HLA A2.1-resticted T cell responses following immunization of PSA-expressing mice by vaccinia-PSA (PROSTVAC). RESULTS Our PSA transgenic mouse showed restricted expression of PSA in the prostate and detectable circulating PSA levels. Additionally, PSA expression was androgen-dependent with reduced PSA expression in the prostate within 1 week of castration, and undetectable PSA by day 42 after castration as evaluated by ELISA. Castration of the PSA/A2.1 hybrid mouse prior to immunization with a PSA-expressing recombinant vaccinia virus resulted in a significant augmentation of PSA-specific cytotoxic lymphocytes. CONCLUSIONS This humanized hybrid mouse model provides a well-defined system to gain additional insight into the mechanisms of immune tolerance to PSA and to test novel strategies aiming at circumventing immune tolerance to PSA and other TAA for targeted prostate cancer immunotherapy. Prostate © 2010 Wiley-Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75780/1/21134_ftp.pd

OxyR is involved in coordinate regulation of expression of fimA and sod genes in Porphyromonas gingivalis

Survival of Porphyromonas gingivalis in the constantly changing oral environment depends on its ability to alter gene expression. We demonstrate here that P. gingivalis activates superoxide dismutase expression in response to oxidative stress and represses expression of FimA, a subunit of major fimbriae. Coordinated expression of fimA and sod is regulated by the redox-sensing transcription factor OxyR. Mutations in the oxyR gene result in a decreased expression of sod and in an elevated expression of fimA. In addition, we provide evidence that regulation of expression of fimA and sod by OxyR is mediated by direct interaction of OxyR and the promoters of these two genes. These results suggest that OxyR plays an important role in regulation of expression of virulence genes in P. gingivalis

Horizontally acquired glycosyltransferase operons drive salmonellae lipopolysaccharide diversity.

The immunodominant lipopolysaccharide is a key antigenic factor for Gram-negative pathogens such as salmonellae where it plays key roles in host adaptation, virulence, immune evasion, and persistence. Variation in the lipopolysaccharide is also the major differentiating factor that is used to classify Salmonella into over 2600 serovars as part of the Kaufmann-White scheme. While lipopolysaccharide diversity is generally associated with sequence variation in the lipopolysaccharide biosynthesis operon, extraneous genetic factors such as those encoded by the glucosyltransferase (gtr) operons provide further structural heterogeneity by adding additional sugars onto the O-antigen component of the lipopolysaccharide. Here we identify and examine the O-antigen modifying glucosyltransferase genes from the genomes of Salmonella enterica and Salmonella bongori serovars. We show that Salmonella generally carries between 1 and 4 gtr operons that we have classified into 10 families on the basis of gtrC sequence with apparent O-antigen modification detected for five of these families. The gtr operons localize to bacteriophage-associated genomic regions and exhibit a dynamic evolutionary history driven by recombination and gene shuffling events leading to new gene combinations. Furthermore, evidence of Dam- and OxyR-dependent phase variation of gtr gene expression was identified within eight gtr families. Thus, as O-antigen modification generates significant intra- and inter-strain phenotypic diversity, gtr-mediated modification is fundamental in assessing Salmonella strain variability. This will inform appropriate vaccine and diagnostic approaches, in addition to contributing to our understanding of host-pathogen interactions

A Novel OxyR Sensor and Regulator of Hydrogen Peroxide Stress with One Cysteine Residue in Deinococcus radiodurans

In bacteria, OxyR is a peroxide sensor and transcription regulator, which can sense the presence of reactive oxygen species and induce antioxidant system. When the cells are exposed to H2O2, OxyR protein is activated via the formation of a disulfide bond between the two conserved cysteine residues (C199 and C208). In Deinococcus radiodurans, a previously unreported special characteristic of DrOxyR (DR0615) is found with only one conserved cysteine. dr0615 gene mutant is hypersensitive to H2O2, but only a little to ionizing radiation. Site-directed mutagenesis and subsequent in vivo functional analyses revealed that the conserved cysteine (C210) is necessary for sensing H2O2, but its mutation did not alter the binding characteristics of OxyR on DNA. Under oxidant stress, DrOxyR is oxidized to sulfenic acid form, which can be reduced by reducing reagents. In addition, quantitative real-time PCR and global transcription profile results showed that OxyR is not only a transcriptional activator (e.g., katE, drb0125), but also a transcriptional repressor (e.g., dps, mntH). Because OxyR regulates Mn and Fe ion transporter genes, Mn/Fe ion ratio is changed in dr0615 mutant, suggesting that the genes involved in Mn/Fe ion homeostasis, and the genes involved in antioxidant mechanism are highly cooperative under extremely oxidant stress. In conclusion, these findings expand the OxyR family, which could be divided into two classes: typical 2-Cys OxyR and 1-Cys OxyR

Listeria monocytogenes (Lm)-LLO Immunotherapies Reduce the Immunosuppressive Activity of Myeloid-derived Suppressor Cells and Regulatory T Cells in the Tumor Microenvironment

Myeloid-derived suppressor cells (MDSC) and regulatory T cells (Treg) are major components of the immune suppressive cells that potentially limit the effectiveness of an immunotherapy-based treatment. Both of these suppressive cell types have been shown to expand in tumor models and promote T-cell dysfunction that in turn favors tumor progression. This study demonstrates that Listeria monocytogenes (Lm)-LLO immunotherapies effect on the suppressive ability of MDSC and Treg in the tumor microenvironment (TME), resulting in a loss in the ability of these cells to suppress T cells. This alteration of immunosuppression in the TME was an inherent property of all Lm-LLO immunotherapies tested and was independent of the tumor model. The virtually total loss in the suppressive ability of these cells in the TME was linked to the reduction in the expression of arginase I in MDSC and IL-10 in Treg. The results presented here provide insight into a novel mechanism of Lm-LLO immunotherapies that potentially contributes to therapeutic antitumor response