Matching Items (90)

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Effect of Rexinoids on Inducing Effector T Cell Chemotaxis

Description

The retinoid-X receptor (RXR) can form heterodimers with both the retinoic-acid
receptor (RAR) and vitamin D receptor (VDR). The RXR/RAR dimer is activated by ligand all
trans retinoic acid (ATRA), which culminates in gut-specific effector T cell migration. Similarly,

The retinoid-X receptor (RXR) can form heterodimers with both the retinoic-acid
receptor (RAR) and vitamin D receptor (VDR). The RXR/RAR dimer is activated by ligand all
trans retinoic acid (ATRA), which culminates in gut-specific effector T cell migration. Similarly,
the VDR/RXR dimer binds 1,25(OH)2D3 to cause skin-specific effector T cell migration.
Targeted migration is a potent addition to current vaccines, as it would induce activated T cell
trafficking to appropriate areas of the immune system and ensure optimal stimulation (40).
ATRA, while in use clinically, is limited by toxicity and chemical instability. Rexinoids
are stable, synthetically developed ligands specific for the RXR. We have previously shown that
select rexinoids can enhance upregulation of gut tropic CCR9 receptors on effector T cells.
However, it is important to establish whether these cells can actually migrate, to show the
potential of rexinoids as vaccine adjuvants that can cause gut specific T cell migration.
Additionally, since the RXR is a major contributor to VDR-mediated transcription and
epidermotropism (15), it is worth investigating whether these compounds can also function as
adjuvants that promote migration by increasing expression of skin tropic CCR10 receptors on T
cells.
Prior experiments have demonstrated that select rexinoids can induce gut tropic migration
of CD8+ T cells in an in vitro assay and are comparable in effectiveness to ATRA (7). The effect
of rexinoids on CD4+ T cells is unknown however, so the aim of this project was to determine if
rexinoids can cause gut tropic migration in CD4+ T cells to a similar extent. A secondary aim
was to investigate whether varying concentrations in 1,25-Dihydroxyvitamin D3 can be linked to
increasing CCR10 upregulation on Jurkat CD4+ T cells, with the future aim to combine 1,25
Dihydroxyvitamin D3 with rexinoids.
These hypotheses were tested using murine splenocytes for the migration experiment, and
human Jurkat CD4+ T cells for the vitamin D experiment. Migration was assessed using a
Transwell chemotaxis assay. Our findings support the potential of rexinoids as compounds
capable of causing gut-tropic migration in murine CD4+ T cells in vitro, like ATRA. We did not
observe conclusive evidence that vitamin D3 causes upregulated CCR10 expression, but this
experiment must be repeated with a human primary T cell line.

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2020-05

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Utilizing Confocal Laser Scanning Microscopy to Visualize Origami Nanostructure Transfection in Primary Immune Cells

Description

An aim of fundamental immunology is quantifying the diversity of the T cell receptor (TCR) repertoire to elucidate the vast recognition by T cells for protection against pathogen and cancer. The utilization of DNA origami nanostructures engineered to capture single

An aim of fundamental immunology is quantifying the diversity of the T cell receptor (TCR) repertoire to elucidate the vast recognition by T cells for protection against pathogen and cancer. The utilization of DNA origami nanostructures engineered to capture single cell paired TCR mRNA sequences has transformed the financial and time requirements of repertoire establishment. To further support this protocol, confocal laser scanning microscopy was implemented following transfection to visualize the stability of the DNA origami within primary immune lymphocytes.

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Date Created
2018-05

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CXCL10-Induced Migration of Triple-Negative Breast Cancer Cells

Description

Inhibitor of growth factor 4 (ING4) is a tumor suppressor of which low expression has been associated with poor patient survival and aggressive tumor progression in breast cancer. ING4 is characterized as a transcription regulator of inflammatory genes. Among the

Inhibitor of growth factor 4 (ING4) is a tumor suppressor of which low expression has been associated with poor patient survival and aggressive tumor progression in breast cancer. ING4 is characterized as a transcription regulator of inflammatory genes. Among the ING4-regulated genes is CXCL10, a chemokine secreted by endothelial cells during normal inflammation response, which induces chemotactic migration of immune cells to the site. High expression of CXCL10 has been implicated in aggressive breast cancer, but the mechanism is not well understood. A potential signaling molecule downstream of Cxcl10 is Janus Kinase 2 (Jak2), a kinase activated in normal immune response. Deregulation of Jak2 is associated with metastasis, immune evasion, and tumor progression in breast cancer. Thus, we hypothesized that the Ing4/Cxcl10/Jak2 axis plays a key role in breast cancer progression. We first investigated whether Cxcl10 affected breast cancer cell migration. We also investigated whether Cxcl10-mediated migration is dependent on ING4 expression levels. We utilized genetically engineered MDAmb231 breast cancer cells with a CRISPR/Cas9 ING4-knockout construct or a viral ING4 overexpression construct. We performed Western blot analysis to confirm Ing4 expression. Cell migration was assessed using Boyden Chamber assay with or without exogenous Cxcl10 treatment. The results showed that in the presence of Cxcl10, ING4-deficient cells had a two-fold increase in migration as compared to the vector controls, suggesting Ing4 inhibits Cxcl10-induced migration. These findings support our hypothesis that ING4-deficient tumor cells have increased migration when Cxcl10 signaling is present in breast cancer. These results implicate Ing4 is a key regulator of a chemokine-induced tumor migration. Our future plan includes evaluation of Jak2 as an intermediate signaling molecule in Cxcl10/Ing4 pathway. Therapeutic implications of these findings are targeting Cxcl10 and/or Jak2 may be effective in treating ING4-deficient aggressive breast cancer.

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Date Created
2019-05

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Immunological Responses to the White-Nose Syndrome Pathogen and their Potential Use as Control

Description

White-nose syndrome (WNS) is a fungal infection devastating bat populations throughout eastern North America. WNS is caused by a fungus, Pseudogymnoascus destructans (Pd), that invades the skin of hibernating bats. While there are a number of treatments being researched, there

White-nose syndrome (WNS) is a fungal infection devastating bat populations throughout eastern North America. WNS is caused by a fungus, Pseudogymnoascus destructans (Pd), that invades the skin of hibernating bats. While there are a number of treatments being researched, there is currently no effective treatment for WNS that is deployed in the field, except a few being tested on a limited scale. Bats have lowered immune function and response during hibernation, which may increase susceptibility to infection during the winter months. Antimicrobial peptides (AMPs) are a crucial component of the innate immune system and serve as barriers against infection. AMPs are constitutively expressed on skin and facilitate wound healing, stimulate other immune responses, and may also stay active on bat skin during hibernation. AMPs are expressed by all tissues, have direct killing abilities against microbes, and are a potential treatment for bats infected with Pd. In this investigation, the fungicidal activity of several readily available commercial AMPs were compared, and killing assay protocols previously investigated by Frasier and Lake were replicated to establish a control trial for use in future killing assays. Another aim of this investigation was to synthesize a bat-derived AMP for use in the killing assay. Sequences of bat-derived AMPs have been identified in bat skin samples obtained from a large geographic sampling of susceptible and resistant species. Contact was made with GenScript Inc., the company from which commercially available AMPs were purchased, to determine the characteristics of peptide sequences needed to synthesize an AMP for lab use. Based on recommendations from GenScript Inc., peptide sequences need to have a hydrophobicity of less than 50% and a sequence length of less than 50 amino acids. These criteria serve as a potential barrier because none of the known bat-derived sequences analyzed satisfy both of these requirements. The final aim of this study was to generate a conceptual model of the immune response molecules activated when bats are exposed to a fungal pathogen such as Pd. Overall, this work investigated sources of variability between trials of the killing assay, analyzed known bat-derived peptide sequences, and generated a conceptual model that will serve as a guideline for identification of immune response molecules on the skin of bats in future proteomics work.

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Date Created
2019-05

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Cloning and expression of antigen-specific T cell receptors

Description

Cancer poses a significant burden on the global health system and represents a leading cause of death worldwide. For late-stage cancers, the traditional treatments of chemotherapy, radiation, and surgery are not always viable, and they can pose unnecessary health risks

Cancer poses a significant burden on the global health system and represents a leading cause of death worldwide. For late-stage cancers, the traditional treatments of chemotherapy, radiation, and surgery are not always viable, and they can pose unnecessary health risks to the patients. New immunotherapies, such as adoptive cell transfer, are being developed and refined to treat such cancers. T cell immunotherapies in particular, where a patient’s T cell lymphocytes are isolated and amplified to be re-infused into the patient or where human cell lines are engineered to express T cell receptors for the recognition of common cancer antigens, are being expanded on because for some cancers, they could be the only option. Constructing an optimal pipeline for cloning and expression of antigen-specific TCRs has significant bearing on the efficacy of engineered cell lines for ACT. Adoptive T cell transfer, while making great strides, has to overcome a diverse T cell repertoire – cloning and expressing antigen-specific TCRs can mediate this understanding. Having identified the high frequency FluM1-specific TCR sequences in stimulated donor PBMCs, it was hypothesized that the antigen-specific TCR could be reconstructed via Gateway cloning methods and tested for expression and functionality. Establishing this pipeline would confirm an ability to properly pair and express the heterodimeric chains. In the context of downstream applications, neoantigens would be used to stimulate T cells, the α and β chains would be paired via single-cell or bulk methods, and instead of Gateway cloning, the CDR3 hypervariable regions α and β chains alone would be co-expressed using Golden Gate assembly methods.

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Date Created
2019-05

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DNA Origami as Novel Immune Adjuvants

Description

Cytokines induced by inflammasome has been used for blood cancer treatments, yet these treatments have been less successful in the solid tumor microenvironment. Here precise-morphology DNA origami structures were implemented to accurately test the effect and mechanism of activation in

Cytokines induced by inflammasome has been used for blood cancer treatments, yet these treatments have been less successful in the solid tumor microenvironment. Here precise-morphology DNA origami structures were implemented to accurately test the effect and mechanism of activation in the NLRP3 inflammasome. THP1 WT cells, a macrophage cell line, were treated with eleven different DNA origami structures. The inflammasome activation of two cytokines, Interleukin 1 beta (IL-1β) and Interferon beta (IFN-β), was measured using HEK Blue IL-1β cells, HEK Blue IFN-β cells, and enzyme linked immunosorbent assay (ELISA). Differences in activation signaling have the potential to provide the characterization required to address the intrinsic complexity of modulating an immune response. It is hoped that DNA origami will help induce more inflammation for solid tumors. The DNA origami was tested in three different volumes: 1 μL, 5 μL, and 10 μL. Overall, the origami that showed promising results were Mg Square. Tetrahedral and P53 block also showed potential but not as well as Mg square. Further testing of more DNA origami structures and testing them in mice are key to the success of targeted cancer immunotherapies in the neoadjuvant setting.

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Date Created
2019-05

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Human Papillomavirus specific immune responses as biomarkers for the early detection of cervical cancer

Description

Human papillomavirus (HPV) is the causative agent of cervical cancer. Persistent infection with high-risk HPV 16, 18 or 45 species is associated with the development and progression of cervical cancer. HPV genotyping and Pap smear tests are the regular methods

Human papillomavirus (HPV) is the causative agent of cervical cancer. Persistent infection with high-risk HPV 16, 18 or 45 species is associated with the development and progression of cervical cancer. HPV genotyping and Pap smear tests are the regular methods used to detect pre-invasive cervical lesions, but there is a need for developing a rapid biomarker to profile immunity to these viruses. The viral E7 oncogene is expressed in most HPV-associated cancers and anti-E7 antibodies can be detected in the blood of patients with cervical cancer. This research was focused on viral E7 oncogene expression to be used in development of low-cost point of care tests, enabling patients from low resource settings to detect the asymptotic stage of cervical cancer and be able to seek treatment early. In order to produce the E7 protein in vitro to measure antibody levels, GST tagged E7 genes from HPV 16, 18 and 45 species were inserted into the pDEST15 vector and expressed in E. coli BL21DE3 cells that were induced with 1mM of IPTG. The E7-GST fused expressed protein was then purified using glutathione beads and resolved on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Protein expression was 5.8 \u03bcg/ml for HPV 16E7 in 500 ml culture and for the 500 ml culture of HPV 18 E7 and 45 E7 were 10.5 \u03bcg/ml and 10.5 \u03bcg/ml for HPV 18E7 and 45E7 respectively. High yield values are showing high expression levels of GST-tagged E7 recombinant protein which can be used for serotyping a number of individuals. This shows that HPV E7 can be produced in large quantities that can potentially be used in point of care tests that can help identify women at risk of cervical cancer. In conclusion, the E7 protein produced in this study can potentially be used to induce humoral responses in patients\u2019 sera for understanding the immune response of cervical cancer.

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Date Created
2018-12

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Effects of LCMV Infection on Murine Fetal Development in Immunized Mothers

Description

Despite a continuously growing body of evidence that they are one of the major causes of pregnancy loss, preterm birth, pregnancy complications, and developmental abnormalities leading to high rates of morbidity and mortality, viruses are often overlooked and underestimated as

Despite a continuously growing body of evidence that they are one of the major causes of pregnancy loss, preterm birth, pregnancy complications, and developmental abnormalities leading to high rates of morbidity and mortality, viruses are often overlooked and underestimated as teratogens. The Zika virus epidemic beginning in Brazil in 2015 brought teratogenic viruses into the spotlight for the public health community and popular media, and its infamy may bring about positive motivation and funding for novel treatments and vaccination strategies against it and a variety of other viruses that can lead to severe congenital disease. Lymphocytic choriomeningitis virus (LCMV) is famous in the biomedical community for its historic and continued utility in mouse models of the human immune system, but it is rarely a source of clinical concern in terms of its teratogenic risk to humans, despite its ability to cause consistently severe ocular and neurological abnormalities in cases of congenital infection. Possibilities for a safe and effective LCMV vaccine remain difficult, as the robust immune response typical to LCMV can be either efficiently protective or lethally pathological based on relatively small changes in the host type, viral strain, viral dose, method of infection/immunization, or molecular characteristics of synthetic vaccination. Introducing the immunologically unique state of pregnancy and fetal development to the mix adds complexity to the process. This thesis consists of a literature review of teratogenic viruses as a whole, of LCMV and its complications during pregnancy, of LCMV immunopathology, and of current understanding of vaccination against LCMV and against other teratogenic viruses, as well as a hypothetical experimental design intended to initially bridge the gaps between LCMV vaccinology and LCMV teratogenicity by bringing a vaccine study of LCMV into the context of viral challenge during pregnancy.

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Date Created
2020-05

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Characterizing the Mucin Layer in Eosinophilic Esophagitis

Description

The purpose of this project was to characterize the mucin layer in patients with eosinophilic esophagitis (EoE). EoE is a chronic disease that is characterized by eosinophilic inflammation in the esophagus. The current diagnosis and standard of care for patients

The purpose of this project was to characterize the mucin layer in patients with eosinophilic esophagitis (EoE). EoE is a chronic disease that is characterized by eosinophilic inflammation in the esophagus. The current diagnosis and standard of care for patients with EoE is less than ideal. Diagnosis is highly invasive as it requires histological confirmation of eosinophilic inflammation in the esophagus, the patient must undergo an upper endoscopy to obtain the tissue sample. The histology as determined by the pathologist is subjective not quantitative which causes significant error in diagnosis. The current treatment methods are dietary therapy or corticosteroids, which require significant cost and time. The pathology of EoE is largely unknown, though it is known to involve allergic inflammatory and type-2 cytokine-mediated responses. Past studies have determined the genetic expression of mucins to be varied in the esophagi of EoE patients using RNA sequencing techniques. The varied expression of mucins in the esophagi of EoE patients has not been validated at the protein level. This study sought to better define mucin protein expression, specifically that of MUC1, MUC4, and MUC7, in the esophagi of EoE patients (n=4) and control patients (n=3). This was accomplished using histological staining. The tissue samples were stained for eosinophil peroxidase (EPX) in order to visualize the eosinophils, which are a pathological marker of EoE. The results of this study showed a qualitative increase in the protein expression of MUC4 in patients with EoE, indicating that MUC4 may play a protective role in the body’s defense against EoE. MUC1 and MUC7 staining showed no pattern. This study defined the conditions necessary for precise staining of esophageal tissues with the MUC4 8G7 antibody. The orientation of the tissue samples on the slides and the small sample size created significant difficulty in analysis and inhibited quantitative analysis. Future studies with tissue orientation standardization and greater sample size are needed to confirm the findings of this study. If verified, the increase of MUC4 protein expression in patients with EoE has implications for EoE diagnostics and therapeutics.

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Date Created
2020-05

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Inhibition of PKR phosphorylation by Vaccinia Virus' E3 Protein

Description

Vaccinia virus is a cytoplasmic, double-stranded DNA orthopoxvirus. Unlike mammalian cells, vaccinia virus produces double-stranded RNA (dsRNA) during its viral life cycle. The protein kinase R, PKR, is one of the principal host defense mechanisms against orthopoxvirus infection. PKR can

Vaccinia virus is a cytoplasmic, double-stranded DNA orthopoxvirus. Unlike mammalian cells, vaccinia virus produces double-stranded RNA (dsRNA) during its viral life cycle. The protein kinase R, PKR, is one of the principal host defense mechanisms against orthopoxvirus infection. PKR can bind double-stranded RNA and phosphorylate eukaryotic translation initiation factor, eIF2α, shutting down protein synthesis and halting the viral life cycle. To combat host defenses, vaccinia virus encodes E3, a potent inhibitor of the cellular anti-viral eIF2α kinase, PKR. The E3 protein contains a C-terminal dsRNA-binding motif that sequesters dsRNA and inhibits PKR activation. We demonstrate that E3 also interacts with PKR by co-immunoprecipitation. This interaction is independent of the presence of dsRNA and dsRNA-binding by E3, indicating that the interaction is not due to dsRNA-bridging.
PKR interaction mapped to a region within the dsRNA-binding domain of E3 and overlapped with sequences in the C-terminus of this domain that are necessary for binding to dsRNA. Point mutants of E3 were generated and screened for PKR inhibition and direct interaction. Analysis of these mutants demonstrates that dsRNA-binding but not PKR interaction plays a critical role in the broad host range of VACV. Nonetheless, full inhibition of PKR in cells in culture requires both dsRNA-binding and PKR interaction. Because E3 is highly conserved among orthopoxviruses, understanding the mechanisms that E3 uses to inhibit PKR can give insight into host range pathogenesis of dsRNA producing viruses.

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Date Created
2017-05