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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Immune Checkpoint Molecule Expression in Canine Lymphoma and Canine Reactive Lymphoid Hyperplasia

Clothier, Stacy Lauren 12 November 2019 (has links)
Background: Although lymphoma is one of the most common malignancies in dogs, remission rates and survival times remain stagnant. Treatment with a multi-agent chemotherapy protocol induces remission for less than one year and the majority of patients relapse. Fewer than 25% of dogs live longer than two years with the currently available treatments. Targeted immunotherapy using checkpoint molecule blockade of PD-1 and PD-L1 shows promise for various types of human cancer, including relapsed/refractory lymphoma; however, little is known regarding the role of these checkpoint molecules in canine lymphoma. Objectives: To determine the patterns of expression of mRNAs encoding PD-1 and its ligands PD-L1 and PD-L2 in lymphoma and reactive lymphoid hyperplasia controls. Methods: Retrospective: formalin-fixed paraffin-embedded (FFPE) tissue from dogs with untreated lymphoma (n=10) and reactive lymphoid hyperplasia (n=10). Prospective: fine-needle aspirates (FNAs) from dogs with untreated lymphoma (n=10) and reactive lymphoid hyperplasia (n=10). Total RNA was extracted, and expression of PD-1, PD-L1, and PD-L2 was measured using qRT-PCR analysis of random-primed cDNA. Checkpoint molecule expression levels were determined using the 2^∆∆CT method. Lymphoma immunophenotype was assessed using immunohistochemical analysis of CD3 and CD79a (FFPE) and review of patient medical records (FNA). Data analysis included Wilcoxon ranksum tests, Dunn's procedure of multiple comparisons, Kruskal-Wallis tests, and regression within an ANOVA. Significance at P < 0.05. Results: PD-1, PD-L1, and PD-L2 expression (normalized internally to 18S rRNA) was lower in lymphoma compared to reactive lymphoid hyperplasia (FFPE); the difference was significant for PD-1 and PD-L2. PD-1 and PD-L2 expression was lower in lymphoma compared to reactive lymphoid hyperplasia (FNA); the difference was significant for PD-1. PD-1, PD-L1, and PD-L2 expression was lower in B cell lymphoma compared to reactive lymphoid hyperplasia (FFPE); this difference was significant for PD-1 and PD-L2. PD-1 and PD-L2 expression was lower in B cell lymphoma compared to reactive lymphoid hyperplasia (FNA); the difference was significant for PD-1. The higher relative abundance of PD-L1 vs PD-1 and PD-L2 vs PD-1 was significantly different between lymphoma and reactive lymphoid hyperplasia (FFPE and FNA). Conclusions: In this study, checkpoint molecule expression was not upregulated in canine lymphoma relative to canine reactive lymphoid hyperplasia, suggesting a limited application of PD-1 and PD-L1 blockade in canine lymphoma. The ligand:receptor relative abundance imbalances reflect the lower PD-1 expression relative to PD-L1 and PD-L2 in lymphoma. Although these results do not suggest that checkpoint inhibitors would be useful for treatment, they give insight into the mechanisms of unchecked lymphocyte proliferation in canine lymphoma. / Master of Science / Lymphoma, a cancer of the white blood cells in the body, is one of the most common malignancies in dogs. Although treatment with a multi-agent chemotherapy protocol results in high remission rates, the remission duration is usually less than one year, with the majority of patients relapsing. In an effort to improve remission rates and survival times, scientists have been working to develop therapeutic interventions that target specific points in the development and replication cycle of a cancer cell. One such strategy, targeting checkpoint molecules programed death (PD)-1 and PD-L1, has shown promise for several different types of human cancers, including lymphoma. PD-1 is a receptor on T cells, which together with its ligands, PD-L1 and PD-L2, decreases lymphocyte function when activated. This is a protective mechanism, acting to inhibit sustained harmful inflammation in a normal healthy dog. Some cancers have taken advantage of this pathway, increasing expression of PD-L1 or L-L2 in order to evade detection by the immune system. To date, little is known regarding the role and expression of these immune checkpoint molecules in dogs with lymphoma. We sought to evaluate if PD-1, PD-L1 and PD-L2 expression is significantly increased in canine lymphoma compared to reactive lymphoid hyperplasia controls. Tissue samples were collected from two sources. Cytology samples of lymphoma and reactive lymphoid hyperplasia were collected by fine needle aspiration from clinical patients. Formalin fixed paraffin embedded tissue samples of lymphoma and reactive lymphoid hyperplasia were collected from the archived tissue bank. Using a molecular analysis technique called quantitative reverse transcription PCR (qRT-PCR) we measured the amount of messenger RNA (mRNA) encoding PD-1 and its ligands PD-L1 and PD-L2 in lymphoma and in reactive lymphoid hyperplasia controls. In our results we did not observe an upregulation in the expression of checkpoint molecules in canine lymphoma relative to canine reactive lymphoid hyperplasia. This suggests there may be a limited therapeutic application for PD-1 and PD-L1/PD-L2 blockade in canine lymphoma. Although these results do not suggest that checkpoint inhibitors would be useful for treatment, they give insight into the mechanisms of unchecked lymphocyte proliferation in canine lymphoma.
2

Immune checkpoint expression in SIV-infected rhesus macaques treated with TLR7 agonists

Shah, Riddhi 27 November 2020 (has links)
While the human immunodeficiency virus (HIV) can be managed with antiretroviral therapy (ART), there is no cure for the disorder. If ART is discontinued, viral RNA levels rapidly increase in most individuals due to the presence of a cell-mediated hidden replication competent viral burden known as the viral reservoir. In order to successfully cure this disease, a mechanism to eliminate the viral reservoir must be developed. Preliminary research completed using a toll-like-receptor agonist 7 (TLR7) has shown favorable results supporting this goal. In a simian immunodeficiency virus (SIV) model, dosing rhesus macaques (RMs) with TLR7 agonists resulted in the development of controlled viremia. A controlled RM is a SIV positive animal that is able to maintain an undetectable viral load without continued therapeutic intervention. In cases of controlled SIV/HIV, viral RNA no longer replicates despite the discontinuation of all treatment. This implies that the viral reservoir is either completely eliminated or severely reduced. In this study, we quantified expression levels of several immune checkpoint and activation markers including CD69, CD39, CXCR5, TCF7, PD-1, PD-L1, TIGIT, CTLA-4, Tim-3, and Lag-3 on isolated peripheral blood mononuclear immune cells (PBMCs) [including CD4+ T cells, CD8+ T cells, natural killer (NK) cells, and B cells] in both controlled and non-controlled RMs. Our goal was to identify possible mechanisms by which controlled RMs are able to successfully modulate the host immune response after discontinuing TLR7 agonist treatment. The subjects each received one of two different TLR7 agonists (GS-9620 and GS-986). Isolated peripheral blood mononuclear cells (PBMCs) were obtained from two controlled RMs and two non-controlled RMs. Samples were analyzed using flow cytometry to identify and quantify levels of markers above. Expression levels of PD-1 and PD-L1 were elevated in PBMCs obtained from non-controlled RMs when compared to levels seen in controlled RMs. In contrast, levels of TIGIT and CTLA4 were downregulated in samples obtained from the controlled RMs. This suggests that immune checkpoint markers responsible for viral control and SIV/HIV pathogenesis have different functional roles. Additionally, the controlled RMs showed high expression of CD69 and CD39 on B cells and increased levels of CXCR5 on CD4+ T cells. This suggests that newly activated B cells likely contribute to the observed improvements in immune function. The results obtained provide favorable support for the potential role of immune checkpoint blockade as an HIV-specific immunotherapy that may contribute to the development of a controlled population. However, it is worthwhile to note that this study was completed using a relatively small sample size (n=4). Thus, interpretations of the findings herein must be replicated with a larger sample prior to forming any definitive conclusions.
3

Immune response in breast cancer

Solinas, Cinzia 24 January 2019 (has links) (PDF)
The immunogenicity of breast cancer (BC) is quite heterogeneous among the clinical subtypes, with immune responses identified most frequently in triple negative (TNBC) and HER2-positive tumors. The extent, spatial localization, distribution patterns, organization and phenotype of the BC immune infiltrate are currently being widely investigated but require standardization before they can be used clinically. One highly relevant unmet clinical need is to understand how immune features are linked to prognosis and potential benefit from treatments, particularly immunotherapy. The present work investigated tumor-infiltrating lymphocytes (TIL), tertiary lymphoid structures (TLS), the expression of multiple targetable inhibitory immune checkpoint molecules (PD-1, PD-L1 and PD-L2, CTLA-4, LAG3 and TIM3) and their clinical relevance in primary BC. Different technical approaches were employed including: flow cytometry (FC) on fresh tissue homogenates; immunohistochemistry (IHC) and immunofluorescence (IF) on formalin-fixed paraffin embedded (FFPE) tissue blocks from untreated primary tumors; and gene expression on a large dataset of BC patients with available long-term survival data. Flow cytometric analysis of PD-1 expression and its principal ligands PD-L1 and PD-L2 together with CTLA-4, LAG3 and TIM3 on TIL in fresh untreated primary tumors revealed that PD-1 and CTLA-4 are most highly expressed on BC TIL and PD-L1 is the principal PD-1 ligand in BC. Immune checkpoint molecule expression parallels the extent of TIL infiltration and TLS presence and number, with the patterns detected similar to that observed in secondary lymphoid organs. Significantly improved disease-specific survival (DSS) has been associated with PD-1hi HER2-enriched and PD-L1hi, PD-L2hi and CTLA-4hi basal-like BC; however there is significant heterogeneity between individual tumors even within the same subtype. These observations suggest that determining expression levels of multiple targetable inhibitory immune checkpoint molecules in patients might help to successfully target them in BC patients most likely to respond.We examined the concordance between two experienced immuno-pathologists who read 800 IHC-stained slides from five independent series over a period of four years to determine the reproducibility of assessing multiple immune biomarkers. This included scoring TIL, TLS, PD-1 and PD-L1 together with detailed information on the spatial localization and cell types expressing these molecules in the tumor microenvironment (TME). The interobserver reproducibility for the assessment of TIL and TLS was consistently good to excellent overtime, while the concordance for PD-L1 evaluation ranged from fair to excellent when it was only expressed on tumor cells (TC); and the concordance for PD-1 evaluation was fair to excellent when it was expressed in TLS and evaluated in primary tumors. Neither PD-L1 expression by TC, nor PD-1 expression within a TLS was significantly associated with prognosis in our datasets.The extent of TIL, TLS and PD-1 and PD-L1 expression were studied in a cohort of TNBC patients who underwent genetic counseling for their personal/familial history of BC or ovarian cancer (OC). This study revealed a remarkable similarity in patterns of immune infiltration between the two cohorts. Interestingly, a higher prevalence of TIL intermediate cases (≥10% and <50% TIL) was detected in the BRCA-mutated cohort, suggesting that this group may be more immunogenic.We next investigated whether the extent and presence of these immune parameters were associated with prognosis in the most highly infiltrated, aggressive BC subtypes (TNBC and HER2-positive). We determined the ideal cut-off for each subtype (TNBC and HER2-positive) to use TIL as a categorical variable. This study found a consistent prognostic impact from TIL (in any tumor compartment including stromal, intratumoral and global areas) and a novel association between PD-L1 expression within TLS and better survival in TNBC. This last effect was driven by baseline stromal TIL, strengthening the importance of reliably quantifying the levels of TIL in BC. Overall, our analyses show that among the targetable inhibitory immune checkpoint molecules investigated in BC, PD-1 and CTLA-4 are most highly expressed by BC TIL and are associated with higher infiltration of TIL; PD-L1 is the principal ligand for PD-1; TIL and TLS are reproducibly scored on IHC-stained tissues; and TIL levels are associated with a better prognosis in TNBC independent of their location in the TME at optimal cut-offs. Our data also provide new insight on targetable inhibitory immune checkpoint molecule expression and location as well as showing a prognostic role for TIL assessed by IHC in primary BC, which identifies these biomarkers as ideal candidates for further investigation. / Doctorat en Sciences médicales (Médecine) / info:eu-repo/semantics/nonPublished
4

Premature clinical trial discontinuation in the era of immune checkpoint inhibitors

Khunger, Monica, Rakshit, Sagar, Hernandez, Adrian V., Pasupuleti, Vinay, Glass, Kate, Galsky, Matthew D., Grivas, Petros January 2018 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / Background: Clinical trial completion is critical for new cancer therapies. Premature trial termination or withdrawal is common and impairs progress. We assessed factors of early terminated/withdrawn oncology trials focusing on trials with immune checkpoint inhibitors (ICI), hypothesizing that the latter may be associated with lower rates of premature discontinuation. Materials and Methods: We reviewed all adult, intervention, oncology trials registered in ClinicalTrials.gov (November 16, 2011, to April 16, 2015) to identify all terminated/withdrawn trials and reasons for termination. Logistics regression model was used to identify factors associated with early termination/withdrawal. Discontinuation rate was compared in trials with and without ICI. Results: We identified 12,875 trials (35% industry funded, 12% federal funded), of which 8.5% were prematurely terminated (5%) or withdrawn (3.5%); the main reasons were poor accrual (33%) and logistical (24%). ICI trials (n = 350) had a nonsignificant lower rate of termination or withdrawal compared with all other oncology trials (5.4% vs. 8.5%; p =.9) and were less likely to discontinue due to poor accrual (nonsignificant difference: 21% vs. 33%; p =.4). ICI trials were also less likely to discontinue compared with all other oncology drug trials (e.g., chemotherapy, targeted inhibitors, antiangiogenesis, biologics; 5.4% vs. 7.9%, respectively, nonsignificant difference). The 4-year cumulative incidence of failing to complete for reasons unrelated to toxicity or efficacy was 18% (95% confidence interval 16%–20%). There was no association between annual incidence across different tumor types or accrual goal and rate of trial termination. Conclusion: Poor accrual represents the main cause of early cancer trial termination. Premature termination/withdrawal rate was not significantly lower in ICI compared with other trials. Clinical trial completion remains a high priority and can be influenced by provider and patient factors. Implications for Practice: Clinical trial completion is critical for new cancer therapies. Premature trial termination or withdrawal is common and impairs progress. This study assessed factors of early terminated/withdrawn oncology trials, focusing on trials with immune checkpoint inhibitors (ICI), and found that poor accrual represents the main cause of early cancer trial termination. Premature termination/withdrawal rate was not significantly lower in immune checkpoint inhibitor trials compared to other trials. The discussion herein is focused on measures taken by the National Cancer Institute and other institutions to improve clinical trial accrual and prevent premature clinical trial discontinuation. / Revisión por pares
5

Re: Maud Rijnders, Ronald de Wit, Joost L. Boormans, Martijn P.J. Lolkema, Astrid A.M. van der Veldt. Systematic Review of Immune Checkpoint Inhibition in Urological Cancers. Eur Urol. 2017;72:411–23

Martinez Merizalde Balarezo, Nelson, Monroe Rivera, Mark, Tejada, Romina A. 03 1900 (has links)
El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado. / “Cartas al editor” / Revisión por pares
6

Immune checkpoint inhibitor-induced inflammatory arthritis: a single center review

Sarazin, Jeffrey 24 November 2020 (has links)
INTRODUCTION: Immune checkpoint inhibitors are a new form of immunotherapy that has transformed the treatment landscape for an ever-increasing number of malignancies. While these medications utilize and enhance the immune system to treat malignancies, they can also have significant side effects, termed immune related adverse events, that in many ways resemble autoimmune disease states. One such example is inflammatory arthritis, which has been found to resemble a number of different presentations, including rheumatoid arthritis and seronegative spondyloarthropathies. In addition to these traditional inflammatory arthritis phenotypes, worsening of pre-existing arthritis is another subgroup of inflammatory arthritis that has previously not been considered in this population. Furthermore, while the effects of these autoimmune arthropathies on functionality is well-documented, it is not known whether there is a significant effect on functionality in patients that experience immune checkpoint inhibitor-induced arthritis. Given that patient reported outcomes are a validated and routinely utilized measure of functionality and quality of life, the Health Assessment Questionnaire, pain visual analogue scale and Patient Global Assessment were used to measure these outcomes following diagnosis. Our aim here is to explore the subtypes of inflammatory arthritis that result from this type of treatment and its overall effect on functionality and quality of life. METHODS: This study was a retrospective review of patients at one academic center who experienced an inflammatory arthritis resulting from immune checkpoint inhibition and required a referral to a rheumatologist for further work-up. Patients were evaluated in clinic at which time they also completed a Health Assessment Questionnaire as part of standard of care. Once patients were evaluated, their inflammatory arthritis was classified based on which clinical arthritis that it matched most closely, including polymyalgia rheumatica, rheumatoid arthritis, seronegative spondyloarthritis, or an exacerbation or osteoarthritis. Other demographic information such as gender, age, and race were also collected. Patient questionnaires were scored and compared to the type of inflammatory arthritis to assess for any correlations. RESULTS: We found 30 patients that had an inflammatory arthritis resulting from immune checkpoint inhibition, with 12 having a polyarthritis similar to rheumatoid arthritis, 11 patients having osteoarthritis exacerbation, 4 patients with a polymyalgia rheumatica arthritis phenotype and 3 patients with a spondyloarthopathy. In terms of the patient reported outcomes, the overall score was 0.57 ± 0.47, indicating that there was little effect of these arthropathies on overall functionality. The pain visual analogue scale had an average score of 41.8 ± 31.4 mm and the Patient Global Assessment had an overall score of 25.6 ± 26.7 mm. DISCUSSION: The overall results suggest that the inflammatory arthritis phenotypes do not significantly impact the functionality or quality of life of most patients who experience this side effect. Given that the use of immune checkpoint inhibitors will continue to grow, the overall need to better understand the resulting arthritis presentations is key. This is perhaps most true for those with pre-existing osteoarthritis, given the widespread nature of the disease in the general population and the prominence of the exacerbation as seen in our cohort.
7

Prediction of patients’ response to immune checkpoint inhibitors in the treatment of advanced NSCLC

Abdo, Mustafa 25 February 2021 (has links)
No description available.
8

VISTA expressed in tumor cells regulates T cell function / 腫瘍細胞に発現する免疫補助シグナル分子VISTA(B7-H5)の機能及び発現メカニズムの解明

Mulati, Kumuluzi 25 March 2019 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第21637号 / 医博第4443号 / 新制||医||1034(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 河本 宏, 教授 松田 道行, 教授 小川 誠司 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
9

Evaluating Immune Modulatory Therapeutic Strategies for Diffuse Intrinsic Pontine Glioma

Furnish, Robin January 2020 (has links)
No description available.
10

EXPLORING THE EFFECT OF CHRONIC INFLAMMATION ON RESPONSE TO IMMUNE CHECKPOINT INHIBITORS IN CANCER

El-Refai, Sherif M. 01 January 2018 (has links)
Precision medicine has allowed for the development of monoclonal antibodies that unmask the anti-tumor immune response. These agents have provided some patients durable clinical benefit. However, PD-1 and PD-L1 inhibitor therapies are effective in a small group (10-20%) of non-small cell lung cancer (NSCLC) patients when used as single-agent therapy. The approved companion diagnostic is expression of the immune cell surface molecule, programmed death ligand 1 (PD-L1), on tumors measured by immunohistochemistry (IHC). Studies in tumor biology and immune surveillance dictate that PD-1 inhibitor efficacy should depend on the level of PD-L1 expression; however, the literature has not followed with convincing evidence. The limitations of this test include timing of tissue acquisition, tumor heterogeneity, and timing of therapy relative to the expression of PD-L1. In addition, the requirement of analyzing tumor tissue biopsy samples from a patient is cumbersome. Thus, a peripheral blood biomarker that predicts efficacy of PD-1/PD-L1 inhibition would be optimal for precise and cost-effective treatment. A history of chronic inflammatory diseases may be advantageous for a cancer patient who is treated with PD-1/PD-L1 inhibitors and may allow them to then mobilize a swift immune response to tumor cells. Specific biological components of this persistent inflammation may predict PD-1 inhibitor response. We have taken a novel approach to leverage national healthcare claims data that couples patient history with response to therapy. We have identified potential peripheral blood biomarkers of response to PD-1/PD-L1 inhibitors using a combination of healthcare outcomes and molecular markers that correlate with therapeutic efficacy.

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