Pathogenic peptides to enhance treatment of glioblastoma: evaluation of RVG-29 from rabies virus and chlorotoxin from scorpion venom

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Description
Glioblastoma (GBM) is a highly invasive and deadly late stage tumor that develops from abnormal astrocytes in the brain. With few improvements in treatment over many decades, median patient survival is only 15 months and the 5-year survival rate hovers

Glioblastoma (GBM) is a highly invasive and deadly late stage tumor that develops from abnormal astrocytes in the brain. With few improvements in treatment over many decades, median patient survival is only 15 months and the 5-year survival rate hovers at 6%. Numerous challenges are encountered in the development of treatments for GBM. The blood-brain barrier (BBB) serves as a primary obstacle due to its innate ability to prevent unwanted molecules, such as most chemotherapeutics, from entering the brain tissue and reaching malignant cells. The GBM cells themselves serve as a second obstacle, having a high level of genetic and phenotypic heterogeneity. This characteristic improves the probability of a population of cells to have resistance to treatment, which ensures the survival of the tumor. Here, the development and testing of two different modes of therapy for treating GBM is described. These therapeutics were enhanced by pathogenic peptides known to improve entry into brain tissue or to bind GBM cells to overcome the BBB and/or tumor cell heterogeneity. The first therapeutic utilizes a small peptide, RVG-29, derived from the rabies virus glycoprotein to improve brain-specific delivery of nanoparticles encapsulated with a small molecule payload. RVG-29-targeted nanoparticles were observed to reach the brain of healthy mice in higher concentrations 2 hours following intravenous injection compared to control particles. However, targeted camptothecin-loaded nanoparticles were not capable of producing significant treatment benefits compared to non-targeted particles in an orthotopic mouse model of GBM. Peptide degradation following injection was shown to be a likely cause for reduced treatment benefit. The second therapeutic utilizes chlorotoxin, a non-toxic 36-amino acid peptide found in the venom of the deathstalker scorpion, expressed as a fusion to antibody fragments to enhance T cell recognition and killing of GBM. This candidate biologic, known as anti-CD3/chlorotoxin (ACDClx) is expressed as an insoluble protein in Nicotiana benthamiana and Escherichia coli and must be purified in denaturing and reducing conditions prior to being refolded. ACDClx was shown to selectively activate T cells only in the presence of GBM cells, providing evidence that further preclinical development of ACDClx as a GBM immunotherapy is warranted.
Date Created
2019
Agent

Cloning and Expression of Antigen-Specific T-Cell Receptors

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Description
T cells, a component of the adaptive immune system, play an instrumental role in directing immune responses and direct cell killing in response to pathogens and cancers. T cells recognize and signal through the T cell receptor, a protein heterodimer

T cells, a component of the adaptive immune system, play an instrumental role in directing immune responses and direct cell killing in response to pathogens and cancers. T cells recognize and signal through the T cell receptor, a protein heterodimer on the surface of T cells. The T cell receptor is a highly variable structure formed via somatic recombination; the structure recognizes peptides presented on the surface of nucleated cells by major histocompatibility complex proteins in a specific receptor-restricted, peptide-restricted manner. This balance between T cell diversity and T cell specificity stands as a barrier to efficacious development of articificial T cell receptors capable of clearing disease. T cell receptors may be tailored to produce pathogen- or cancer-specific immune responses from autologous T cell populations. This necessitates a pipeline for amplification, cloning, and expression of antigen-specific T cell receptors. This study aims to utilize influenza-specific T cell receptor chains from healthy donor T cells to test a model for T cell receptor cloning and expression. This study utilizes Gateway recombination for high-throughput cloning into mammalian expression vectors. This study has successfully amplified and cloned T cell receptor chains from a population of influenza-specific T cells from donor cell transcripts into mammalian cell expression vectors. Additionally, CD8, a coreceptor for the T cell receptor complex, was successfully cloned and inserted into a vector for expression in mammalian cells. Sanger sequencing has confirmed sequences for influenza-specific T cell receptor chains and the CD8 chain. Future application of this project includes expression in mammalian non-T cells to test for efficacy of expression and, ultimately, expression in cytotoxic cells to create lymphocytes capable of antigen-specific recognition and cytolytic killing of cells of interest.
Date Created
2019-05
Agent

Cloning and expression of antigen-specific T cell receptors

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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.
Date Created
2019-05
Agent

Temozolomide-induced autophagy enhances Glioblastoma Multiforme cell death in combination with inhibitors of the PI3K/AKT pathway

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Description
Patients diagnosed with GBM, a highly migratory, heterogeneous, rapidly growing primary adult brain tumor are faced with a dismal prognosis. Recent research has shed light on cell-survival pathways that are induced after the DNA-damage response induced by TMZ. Autophagy, a

Patients diagnosed with GBM, a highly migratory, heterogeneous, rapidly growing primary adult brain tumor are faced with a dismal prognosis. Recent research has shed light on cell-survival pathways that are induced after the DNA-damage response induced by TMZ. Autophagy, a major catabolic process meant to degrade damaged organelles and large misfolded proteins, has recently been shown to be activated by TMZ. However, a precise mechanism has not yet been determined. T98G cells treated with TMZ showed significant induction of unfolded protein response (UPR) markers such as GRP78, and LC3-II expression, indicating increased autophagosome formation. Additional experiments have used the autophagic inhibitor Bafilomycin A1 (Baf) to determine that autophagic flux is induced, supporting the conclusion that UPR induction by TMZ induces autophagy. Combination treatments with PI3K inhibitors PX-866 and BEZ235 with Baf as a means to shut down two critical mechanisms of GBM cell survival were explored in this research. PX-866 was found to inhibit autophagy, while BEZ235, was found to induce autophagy. The differential modulation of autophagy by these PI3K inhibitors offers new knowledge for utilizing more effective drug combinations to treat GBM and improve patient survival.
Date Created
2019-05
Agent

INVESTIGATING ECCRINE SWEAT AS A NONINVASIVE BIOMARKER RESOURCE

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Description
Background: Recent interests in continuous biomonitoring and the surge of wearable biotechnology demand a better understanding of sweat as a noninvasive biomarker resource. The ability to use sweat as a biofluid provides the opportunity for noninvasive early and continuous diagnostics.

Background: Recent interests in continuous biomonitoring and the surge of wearable biotechnology demand a better understanding of sweat as a noninvasive biomarker resource. The ability to use sweat as a biofluid provides the opportunity for noninvasive early and continuous diagnostics. This thesis serves to help fill the existing knowledge gap in sweat biomarker discovery and applications.

Experimental Design: In part one of this study, exercise-induced eccrine sweat was collected from 50 healthy individuals and analyzed using mass spectrometry, protein microarrays, and quantitative ELISAs to identify a broad range of proteins, antibody isotypes, and cytokines in sweat. In part two of this study, cortisol and melatonin levels were analyzed in exercise-induced sweat and plasma samples collected from 22 individuals.

Results: 220 unique proteins were identified by shotgun analysis in pooled sweat samples. Detectable antibody isotypes include IgA (100% positive; median 1230 ± 28 700 pg/mL), IgD (18%; 22.0 ± 119 pg/mL), IgG1 (96%;1640 ± 6750 pg/mL), IgG2 (37%; 292 ± 6810 pg/mL), IgG3 (71%;74.0 ± 119 pg/mL), IgG4 (69%; 43.0 ± 42.0 pg/mL), and IgM (41%;69.0 ± 1630 pg/mL). Of 42 cytokines, three were readily detected in all sweat samples (p<0.01). The median concentration for interleukin-1α was 352 ± 521 pg/mL, epidermal growth factor was 86.5 ± 147 pg/mL, and angiogenin was 38.3 ± 96.3 pg/mL. Multiple other cytokines were detected at lower levels. The median and standard deviation of cortisol was determined to be 4.17 ± 11.1 ng/mL in sweat and 76.4 ± 28.8 ng/mL in plasma. The correlation between sweat and plasma cortisol levels had an R-squared value of 0.0802 (excluding the 2 highest sweat cortisol levels). The median and standard deviation of melatonin was determined to be 73.1 ± 198 pg/mL in sweat and 194 ± 93.4 pg/mL in plasma. Similar to cortisol, the correlation between sweat and plasma melatonin had an R-squared value of 0.117.

Conclusion: These studies suggest that sweat holds more proteomic and hormonal biomarkers than previously thought and may eventually serve as a noninvasive biomarker resource. These studies also highlight many of the challenges associated with monitoring sweat content including differences between collection devices and hydration, evaporation losses, and sweat rate.
Date Created
2019-05
Agent

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

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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.
Date Created
2018-12
Agent

Serum Immune Profiling for Early Detection of Cervical Disease

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Description

Background: The most recent (2012) worldwide estimates from International Agency for Research on Cancer indicate that approximately 528,000 new cases and 270,000 deaths per year are attributed to cervical cancer worldwide. The disease is preventable with HPV vaccination and with

Background: The most recent (2012) worldwide estimates from International Agency for Research on Cancer indicate that approximately 528,000 new cases and 270,000 deaths per year are attributed to cervical cancer worldwide. The disease is preventable with HPV vaccination and with early detection and treatment of pre-invasive cervical intraepithelial neoplasia, CIN. Antibodies (Abs) to HPV proteins are under investigation as potential biomarkers for early detection.

Methods: To detect circulating HPV-specific IgG Abs, we developed programmable protein arrays (NAPPA) that display the proteomes of two low-risk HPV types (HPV6 and 11) and ten oncogenic high-risk HPV types (HPV16, 18, 31, 33, 35, 39, 45, 51, 52 and 58). Arrays were probed with sera from women with CIN 0/I (n=78), CIN II/III (n=84), or invasive cervical cancer (ICC, n=83).

Results: Abs to any early (E) HPV protein were detected less frequently in women with CIN 0/I (23.7%) than women with CIN II/III (39.0%) and ICC (46.1%, p<0.04). Of the E Abs, anti-E7 Abs were the most frequently detected (6.6%, 19.5%, and 30.3%, respectively). The least frequently detected Abs were E1 and E2-Abs in CIN 0/I (1.3%) and E1-Abs in CIN II/III (1.2%) and ICC (7.9%). HPV16-specific Abs correlated with HPV16 DNA detected in the cervix in 0% of CIN 0/I, 21.2% of CIN II/III, and 45.5% of ICC. A significant number (29 - 73%) of E4, E7, L1, and L2 Abs had cross-reactivity between HPV types.

Conclusion: HPV protein arrays provide a valuable high-throughput tool for measuring the breadth, specificity, and heterogeneity of the serologic response to HPV in cervical disease.

Date Created
2017-08-23
Agent

Assessing the Evolutionary Divergence Between Four Multiple Myeloma Patient Tumors and Their Established Cell Lines

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Description
Current studies in Multiple Myeloma suggest that patient tumors and cell lines cluster separately based on gene expression profiles. Hyperdiploid patients are also extremely underrepresented in established human myeloma cell lines (HMCLs). This suggests that the average HMCL model system

Current studies in Multiple Myeloma suggest that patient tumors and cell lines cluster separately based on gene expression profiles. Hyperdiploid patients are also extremely underrepresented in established human myeloma cell lines (HMCLs). This suggests that the average HMCL model system does not accurately represent the average myeloma patient. To investigate this question we performed a combined CNA and SNV evolutionary comparison between four myeloma tumors and their established HMCLs (JMW-1, VP-6, KAS-6/1-KAS-6/2 and KP-6). We identified copy number changes shared between the tumors and their cell lines (mean of 74 events - 59%), those unique to patients (mean of 21.25 events - 17%), and those only in the cell lines (mean of 30.75 events \u2014 24%). A relapse sample from the JMW-1 patient showed 58% similarity to the primary diagnostic tumor. These data suggest that, on the level of copy number abnormalities, HMCLs show equal levels of evolutionary divergence as that observed within patients. By exome sequencing, patient tumors were 71% similar to their representative HMCLs, with ~12.5% and ~16.5% of SNVs unique to the tumors and HMCLs respectively. The HMCLs studied appear highly representative of the patient from which they were derived, with most differences associated with an enrichment of sub-populations present in the primary tumor. Additionally, our analysis of the KP-6 aCGH data showed that the patient's hyperdiploid karyotype was maintained in its respective HMCL. This discovery confirms the establishment and validation of a novel and potentially clinically relevant hyperdiploid HMCL that could provide a major advance in our ability to understand the pathogenesis and progression of this prominent patient population.
Date Created
2016-05
Agent

Recombinant Baculoviral Production of Class I Major Histocompatibility Complex Tetramers

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Description
Identifying immunoreactive cytotoxic T lymphocytes (CTLs) by current technologies (cytokine secretion, intracellular cytokine, ELISPOT, and MHC tetramer assays) is often difficult when probing for multiple target antigens. CTLs activate and induce apoptosis of pathogenic cells when T-cell receptors (TCRs) specifically

Identifying immunoreactive cytotoxic T lymphocytes (CTLs) by current technologies (cytokine secretion, intracellular cytokine, ELISPOT, and MHC tetramer assays) is often difficult when probing for multiple target antigens. CTLs activate and induce apoptosis of pathogenic cells when T-cell receptors (TCRs) specifically bind to antigenic peptides and major histocompatibility complexes (pMHCs) presented on the target cell’s surface. Flow cytometric MHC class I tetramer assays allow for the direct quantification and sorting of most CD8+ T lymphocytes whose TCRs recognize bound peptides, regardless of effector function. Class I tetramers are traditionally produced using BL21-DE3 E. coli expression, denaturation and folding in vitro, which is technically challenging, time-consuming, and low-throughput. We are developing an assay amenable to rapid, high-throughput screening of peptide libraries to characterize and quantitate antigen-specific CTLs in peripheral blood mononuclear cells (PBMCs). Baculovirus expression systems, utilizing host eukaryotic chaperones and isomerases, are capable of producing soluble, properly-folded protein complexes with high yields. The HLA-A*0201 heavy chain and beta-2-microglobulin genes were cloned into pIEx baculovirus expression vectors. Recombinant HLA-A*0201 and β2m viruses were synthesized using the BacMagic-3 DNA/pIEx method and transfected into Spodoptera frugiperda (Sf9) cells, and protein expression was confirmed by Western blot. To prepare T cells for testing, PBMCs from a healthy HLA-A2+ donor were collected and pulsed with DMSO control or CEF peptide pool (a mixture of CMV-, EBV-, and Flu-specific HLA class I epitopes). After 5 days, the CD8+ and CD8- fractions were sorted by MACS-based magnetic separation, and the frequency of FluM1-specific lymphocytes in the CD8+ populations was determined (0.1% of DMSO control vs. 0.772% of CEF-pulsed cells) using a commercial tetramer. We are optimizing HLA-A*0201 and β2m baculovirus co-infection ratios and evaluating the efficiency of intracellular MHC folding.
Date Created
2016-05
Agent

Creating an artificial antigen presenting cell system for HPV16 proteins

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Description
Background: High risk types of human papillomavirus (HPV) are known to cause cancer, including cervical (99%) and oropharyngeal cancer (70%). HPV type 16 is the most common subtype. Three antigens that are critical for integration or tumor progression are E2,

Background: High risk types of human papillomavirus (HPV) are known to cause cancer, including cervical (99%) and oropharyngeal cancer (70%). HPV type 16 is the most common subtype. Three antigens that are critical for integration or tumor progression are E2, E6 and E7. In this study, we developed a systematic approach to identify naturally-processed HPV16-derived HLA class I epitopes for immunotherapy development. Methods: K562 cells, which lack HLA expression, were transduced with each HPV16 antigen using lentivirus and supertransfected with HLA-A2 by nucleofection. Stable cell lines expressing each antigen were selected for and maintained throughout the investigation. In order to establish a Gateway-compatible vector for robust transient gene expression, a Gateway recombination expression cloning cassette was inserted into the commercial Lonza pMAX GFP backbone, which has been experimentally shown to display high transfection expression efficiency. GFP was cloned into the vector and plain K562 cells were transfected with the plasmid by nucleofection. Results: Expression of K562-A2 was tested at various time points by flow cytometry and A2 expression was confirmed. Protein expression was shown for the transduced K562 E7 by Western blot analysis. High transfection efficiency of the pMAX_GFP_Dest vector (up to 97% GFP+ cells) was obtained 48 hours post transfection, comparable to the commercial GFP-plasmid. Conclusion: We have established a rapid system for target viral antigen co-expression with single HLA molecules for analysis of antigen presentation. Using HPV as a model system, our goal is to identify specific antigenic peptide sequences to develop immunotherapeutic treatments for HPV-associated cancers.
Date Created
2016-05
Agent