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CAR-T cell immunotherapy is a highly efficacious treatment for CD19-positive hematological malignancies, however, some patients are non-responsive for reasons that are not well understood. Clinical efficacy has been correlated with long-term persistence, a propensity that can be predicted by the differentiation state of transplanted cells. Despite this, decades-old methods for expanding T cells have not been updated to prevent the deleterious effects of excessive differentiation in CAR-T cells. Uncoupling proliferation and differentiation is a long-held goal in the field of immunotherapy with both cytokines and pharmacological approaches being implemented to dissociate these parallel processes. Histone methyltransferases rewire transcriptional programs in T cells and simultaneously regulate multitudes of genes, making them attractive targets for modifying the proliferation-differentiation axis. Despite this, only a handful of studies have examined their role in regulating the transcriptional programs of human CD8+ T cells. MLL4 (encoded by KMT2B) belongs to the six-member group of MLL histone methyltransferases. MLL1, a paralog of MLL4, has been implicated in regulating the maintenance of IL-4 and GATA-3 expression in TH2 CD4 memory T cell populations, however the function of MLL4 in human CD8+ T cells is unknown. We report a critical role for MLL4 in the proliferation and differentiation of CD8+ T cells. CRISPR-Cas9-editing of MLL4 uncoupled the processes of proliferation and differentiation, increasing proliferation but maintaining central memory T cell (TCM)-like populations, allowing for the production of increased numbers of TCM-like CD62L+CD45RO+ cells. Pharmacologically inhibiting the MLL4-Menin complex with MI-2 during T cell expansion enriched the frequency of minimally differentiated TCM-like CD8+ T cells. TCM-associated CD62L, CCR7, CD122 and CD127 surface markers were upregulated and early memory-associated transcription factor TCF7, LEF1, EOMES, and FOXP1 transcripts were increased. CD8+ CAR-T cells expanded in the presence of MI-2 responded earlier, while improving both tumor burden and survival in a NSG xenograft model of human leukemia. This finding has important translational impact in improving the persistence and proliferative capacity of CD8+ CAR-T cells. / Infectious Disease & Immunity

HPV-associated cancer and carcinoma of the prostate are responsible for significant worldwide morbidity and mortality. The viral transforming proteins E6 and E7 make human papilloma virus positive (HPV+) malignancies an attractive target for cancer immunotherapy however, therapeutic vaccination exerts limited efficacy in the setting of advanced disease. In prostatic carcinoma therapeutic vaccination shows some therapeutic activity but is infrequently curative. A strategy to induce substantial specific immune responses against multiple epitopes of E6 and E7 proteins based on an attenuated transgene from HPV serotypes 16 and 18, that is incorporated into MG1-Maraba virotherapy (MG1-E6E7), was designed. MG1-E6E7 is able to boost specific immunity following priming with either an adenoviral vector (Ad-E6E7) or customised synthetic peptide vaccines resulting in multifunctional CD8+ T cell responses of an enormous magnitude. MG1-E6E7 vaccination in the HPV+ murine model TC1 is curative against large tumours in a CD8+ dependent manner and results in durable immunologic memory. Using the same adenoviral prime and MG1 boosting strategy targeting the prostatic antigen, STEAP, immunity against multiple CD8+ STEAP epitopes was induced. In a murine prostate cancer model, STEAP specific oncolytic virotherapy significantly improved the survival of mice bearing advanced TRAMP-C2 tumours. One significant obstacle to therapeutic cancer vaccination is an immunosuppressive tumour microenvironment. MG1 Maraba is able to lethally infect HPV-associated and prostate cancer cells, increase the immunologic activity within the tumour microenvironment in vivo and exploit molecular hallmarks of HPV-positive cancer and prostatic carcinoma enabling infection of bulky tumours. Pre-clinical data generated within this thesis has been instrumental in securing funding for future clinical trials assessing the safety and activity of MG1 Maraba virotherapy for HPV-associated cancer and prostatic carcinoma. This promising approach has the potential to be directly translatable to human clinical oncology to tackle these two highly prevalent and frequently lethal groups of epithelial neoplasia. / Thesis / Doctor of Philosophy (PhD) / Carcinoma (epithelial cancer) is the most common form of human cancer and two frequently encountered types, namely HPV-associated and prostatic carcinoma are responsible for a substantial worldwide cancer burden. Current therapeutic options show limited clinical benefit and/ or significant long-term side effects for advanced carcinomas, therefore new treatments are urgently required. Oncolytic viruses represent an exciting new form of anti-tumour immunotherapy capable of infecting and killing cancerous cells; here we present a virus called MG1 Maraba that is able to exploit molecular characteristics of these cancers. When MG1 Maraba is engineered to target proteins from HPV-associated cancer and prostatic carcinoma, specific immune attack against these tumours occur in mouse cancer models. MG1 Maraba offers a novel, selective, safe and highly promising therapeutic approach against advanced carcinomas. Based on the information within this thesis human clinical trials assessing MG1 Maraba are due to take place for both HPV-associated and prostate cancer.

The field of immuno-oncology has made tremendous advances in the treatment of cancer. Adoptive cellular transfer (ACT) of tumor-specific T cells and oncolytic viruses (OVs) are powerful anti-tumor agents, but each modality faces significant challenges. Despite the promise of ACT against hematological malignancies, success has been limited in solid tumors. OVs preferentially lyse tumor cells, but have difficulty overcoming antiviral host factors when delivered systemically – therapeutic doses must therefore be quite high to achieve tumor delivery. One means of overcoming viral neutralization is by loading OV onto cellular carriers prior to treatment. Since engineered T cells and OVs both possess anticancer activity, and since viruses naturally associate with nearby circulating immune cells, employing T cells engineered with a T cell antigen coupler (TAC) receptor as viral carriers may offer an ideal combination. Our studies indicated that loading oncolytic maraba virus (MRB) onto T cells – engineered with a TAC receptor targeting HER2 – had no impact on the functionality or receptor expression of these T cells. OV loaded on the surface of these TAC-T cells enabled killing of a variety of tumor targets that may be otherwise resistant to TAC-T cell therapy. Efficacy remains to be elucidated in vivo using xenograft murine models due to the lack of a protective antiviral immune response, which ultimately resulted in encephalopathy. These observed toxicities were likely model-specific, as MRB has shown to be highly attenuated in healthy tissues of wild type models. While conceptually attractive, using TAC-T cells as viral carriers to deliver a multi-pronged, one-pot antitumor therapy directly to the site of the tumor requires further evaluation before considering human studies. / Thesis / Master of Science (MSc)

Asthma is defined as reversible airflow obstruction and an estimated 1-in-3 Canadians will be diagnosed over their lifetime. Many clinical phenotypes of asthma exist, but allergic asthma is the most common presentation. Despite effective therapies, approximately 65% of Canadian asthmatics have poorly controlled disease. Thus, there remains pressing need to develop disease modifying therapies. Allergen-specific immunotherapy (SIT) is a disease-modifying therapy for allergic disease that consists of repeatedly administering doses of allergen, to an allergic individual; over 100 years of clinical use, SIT has been demonstrated to reduce symptoms of disease both during and after cessation of therapy. Widespread clinical uptake of SIT has been limited by the risk of developing anaphylaxis as a response to therapy. Peptide immunotherapy is a derivation of SIT, that attempts to retain the disease-modifying benefits, while lessening the risk of anaphylaxis, by treating subjects with allergen-derived T-cell peptide epitopes. Peptide immunotherapy has been demonstrated to reduce symptoms of allergic disease in treated subjects; however, it remains unknown how administration of a single (or several) T-cell epitopes can modulate immune responses to entire complex allergens. Additionally, how genetic diversity in peptide epitope presentation effects the development of immune tolerance is unknown. In this thesis, we sought to characterize these mechanisms of peptide immunotherapy; the hypothesis was, “The induction of immunosuppression by peptide immunotherapy involves the infectious spread of tolerance beyond the treatment epitope, and is dependent upon treatment peptide dose and affinity to MHC”. Through the definition of these mechanistic traits we hoped to expedite and inform the design of future peptide based therapeutics. The studies presented within this thesis examine the topic of immune modulation of allergic disease in mouse models, and have focused upon broadly pertinent characteristics of immune modulation, such as the number, dose and affinity of immunomodulatory epitopes. / Thesis / Doctor of Philosophy (PhD) / Asthma is a disease of the airways that can cause difficulties in breathing. In some people, asthma develops because their immune system reacts in an uncontrolled manner to common environmental proteins, called allergens. Whole allergen immunotherapy is a treatment for asthma, where asthmatic people are injected with doses of allergen until their immune system no longer responds to (or ‘tolerates’) the allergen. In some people, injection of allergen can lead to a life-threatening immune response known as ‘anaphylaxis’. Peptide-immunotherapy is a form of whole allergen immunotherapy where people are given small fragments of the allergen (a ‘peptide’) rather than the whole allergen. The benefit of peptide immunotherapy is that the treatment peptides are too small to cause anaphylaxis, but remain large enough to teach the immune system. In this thesis, we examined how treatment with small peptides teaches the immune system to tolerate the larger and more complex whole allergen.

Immunotherapy offers a promising approach to cancer treatment by harnessing a patient’s own immune system to fight malignant cells. However, the clinical application of immunotherapy has been hindered by the immunosuppressive tumor microenvironment generated by cancer cells as a mechanism to impede immune function and evade immune detection. Clinically used immunotherapies, such as immune checkpoint inhibitors and adoptive cell therapy, aim to overcome the immunosuppressive tumor microenvironment by blocking key regulatory pathways and exogenously activating immune cells. While effective against some cancers, these therapies are still limited by systemic toxicity, poor delivery kinetics, and continuous tumor adaptation that leads to immune escape. Herein, we propose the synthesis of nanoscale branching DNA architectures, known as dendrons, to (1) encode and deliver a DNA sequence, termed G3YSD, capable of activating the cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway; and (2) deliver epigenetic modifiers to reprogram immunosuppressive cues in tumor cells. This solution exploits the modularity, programmability, and ease of control over DNA synthesis to generate architectures that exhibit improved delivery kinetics and favorable presentation of cargo to enhance immunomodulatory effects. Our proposed solution directly targets immunosuppressive mechanisms in tumor cells to sensitize them to immune attack and make them more easily recognized by the immune system. Delivery of G3YSD-encoding dendrons to murine B16 melanoma significantly increased the expression of major histocompatibility complex I (MHC I) and programmed cell death-ligand 1 (PD-L1) surface-bound receptors, which are critical for immune signaling pathways. The chemical conjugation of romidepsin, a histone deacetylase inhibitor, to G3YSD-encoding dendrons resulted in more than a 2-fold increase in MHC I expression compared to unconjugated G3YSD sequences and free romidepsin, indicating that the spatial arrangement and presentation of romidepsin has a synergistic impact on cGAS-STING signaling. In addition, pretreatment of B16 melanoma cells with zebularine, a DNA methyltransferase inhibitor, followed by G3YSD-encoding dendrons significantly increased levels of cytotoxic T lymphocyte-mediated lysis in a physiologically relevant co-culture. Developing novel architectures capable of interacting with tumor cells to remodel and overcome immunosuppressive cues will lead to significant advances in the field of immunotherapeutic design and cancer treatment. / 2026-05-23T00:00:00Z

Breast cancer is one of the most common cancer types in women and its metastases cause most patient deaths in the advanced stage of this disease. 1,2,3 Unfortunately, metastases develop drug resistance to chemotherapy and impaired T lymphocyte infiltration into metastatic lesions by compressing blood vessels. 4,5,10,11,12 Although losartan decompressed vessels and increased the presence of T lymphocytes in the metastatic lesions, T-cells were not effective at eliminating tumors.10 In this thesis, we generated chimeric antigen receptor constructs that have specificity against epithelial cell adhesion molecule (EpCAM). After optimizing a retroviral transfection/transduction system, we successfully generated EpCAM CAR T-cells and tested their efficacy against tumor spheroids. We noticed a dramatic reduction of spheroids' area and spheroids' diameter after 36 hours of treatment and observed spheroids’ destruction and tumor cell elimination after 96 hours of treatment, compared to non-specific stimulated T-cells treatment on tumor spheroids. EpCAM CAR T-cells have been shown to be effective against cancer in vitro; therefore, injection of EpCAM CAR T-cells into mice with breast cancer will be conducted to determine whether losartan is able to improve infiltration. We expect that the use of losartan will improve the number of infiltrated CAR-T-cells and their efficacy against breast tumors.

Immune checkpoint blockade antibodies have promising clinical applications but suffer from disadvantages such as severe toxicities and moderate patient-response rates. None of the current delivery strategies, including local administration aiming to avoid systemic toxicities, can sustainably supply drugs over the course of weeks; adjustment of drug dose, either to lower systemic toxicities or to augment therapeutic response, is not possible. Herein, an implantable miniaturized device has been developed using electrode-embedded optical fibers with both local delivery and measurement capabilities over the course of a few weeks. The combination of local immune checkpoint blockade antibodies delivery via this device with photodynamic therapy elicits a sustained anti-tumor immunity in multiple tumor models. Named Implantable Miniature Optical Fiber Device (IMOD), this device uses tumor impedance measurement for timely presentation of treatment outcomes, and allows modifications to the delivered drugs and their concentrations, rendering IMOD as outstandingly valuable for on-demand delivery of potent immunotherapeutics without exacerbating toxicities. Rigorous studies performed using IMOD are presented and discussed in the follow chapters, followed by exploration of proposed work to expand the breadth of functions offered by this implantable biomedical platform. / Doctor of Philosophy / Aside from efficient energy and data transfer, optical fibers today are used in varying fields including optogenetics and neuroscience. However, merging fiber optics with therapeutics against cancer has rarely been reported. We establish a versatile polymer/drug integrated optical fiber for both diagnosis and treatment of cancers, with minimum mechanical invasiveness. Release profiles of polymer/drug nanoparticles loaded onto our fibers, regardless of their hydrophilicity, can be adjusted to accommodate both short-term and long-term delivery specifications. This enhances intratumoral drug accumulation with minimal systemic toxicity, thus overcoming the dosing obstacle. The optical fibers are also ideal to be utilized during photodynamic therapy (PDT), since photosensitizers can be easily incorporated and activated by near-infrared light traveling through the fibers. Hollow channel within the optical fiber allows for repetitive on-demand delivery of immune checkpoint inhibitors to surrounding tumor tissue, thus stimulating and reactivating cytotoxic and helper T cells. The synergistic combination of PDT and immunotherapy can potentially boost the tumor-targeted treatment outcome by numerous folds. Lastly, our optical fibers are adaptable to integrate biosensing functionality. Devices are built upon the optical fibers to monitor treatment outcome along tumor regression. Our data establishes a correlation between tumor impedance and tumor volumes, thus allowing us to track tumor progression and treatment response towards administered treatments.

Yes / Hymenoptera venom allergy is a potentially life‐threatening allergic reaction following a honeybee, vespid, or ant sting. Systemic‐allergic sting reactions have been reported in up to 7.5% of adults and up to 3.4% of children. They can be mild and restricted to the skin or moderate to severe with a risk of life‐threatening anaphylaxis. Patients should carry an emergency kit containing an adrenaline autoinjector, H1‐antihistamines, and corticosteroids depending on the severity of their previous sting reaction(s). The only treatment to prevent further systemic sting reactions is venom immunotherapy. This guideline has been prepared by the European Academy of Allergy and Clinical Immunology's (EAACI) Taskforce on Venom Immunotherapy as part of the EAACI Guidelines on Allergen Immunotherapy initiative. The guideline aims to provide evidence‐based recommendations for the use of venom immunotherapy, has been informed by a formal systematic review and meta‐analysis and produced using the Appraisal of Guidelines for Research and Evaluation (AGREE II) approach. The process included representation from a range of stakeholders. Venom immunotherapy is indicated in venom‐allergic children and adults to prevent further moderate‐to‐severe systemic sting reactions. Venom immunotherapy is also recommended in adults with only generalized skin reactions as it results in significant improvements in quality of life compared to carrying an adrenaline autoinjector. This guideline aims to give practical advice on performing venom immunotherapy. Key sections cover general considerations before initiating venom immunotherapy, evidence‐based clinical recommendations, risk factors for adverse events and for relapse of systemic sting reaction, and a summary of gaps in the evidence. / European Union's Seventh Framework Programme FP7. Grant Number: 601763

Yes / Background:To inform the development of the European Academy of Allergy and Clinical Immunology’s (EAACI) Guidelines on Allergen Immunotherapy (AIT) for allergic asthma, we assessed the evidence on the effectiveness, cost-effectiveness and safety of AIT. Methods:We performed a systematic review, which involved searching nine data-bases. Studies were screened against predefined eligibility criteria and critically appraised using established instruments. Data were synthesized using random-effects meta-analyses.Results:98 studies satisfied the inclusion criteria. Short-term symptom scores were reduced with a standardized mean difference (SMD) of 1.11 (95% CI 1.66, 0.56). This was robust to a prespecified sensitivity analyses, but there was evidence suggestive of publication bias. Short-term medication scores were reduced SMD 1.21 (95% CI 1.87, 0.54), again with evidence of potential publication bias. There was no reduction in short-term combined medication and symptom scores SMD 0.17 (95% CI 0.23, 0.58), but one study showed a beneficial long-term effect. For secondary outcomes, subcutaneous immunotherapy (SCIT) improved quality of life and decreased allergen-specific airway hyperreactivity (AHR), but this was not the case for sublingual immunotherapy (SLIT). There were no consistent effects on asthma control, exacerbations, lung function, and nonspecific AHR. AIT resulted in a modest increased risk of adverse events (AEs). Although relatively uncommon, systemic AEs were more frequent with SCIT; however no fatalities were reported. The limited evidence on cost-effectiveness was mainly available for sublingual immunotherapy (SLIT) and this suggested that SLIT is likely to be cost-effective. Conclusions: AIT can achieve substantial reductions in short-term symptom and medication scores in allergic asthma. It was however associated with a modest increased risk of systemic and local AEs. More data are needed in relation to secondary outcomes, longer-term effectiveness and cost-effectiveness. / EAACI; BM4SIT. Grant Number: 601763; European Union's Seventh Framework Programme FP7