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- All Subjects: Immunology
- All Subjects: immunotherapy
- Creators: Blattman, Joseph
Description
Efforts to quantify the diversity of the T cell repertoire have generally been unsuccessful because not all factors accounting for diversity have been considered. In order to get an accurate representation of the T cell repertoire, one must incorporate analysis of germline gene diversity, diversity from somatic recombination, joining diversity from N- and P- nucleotides, and TCR chain pairing diversity. Because of advances in high-throughput sequencing techniques, estimates have been able to account for diversity from TCR genes. However the ability to account for chain pairing diversity has been more difficult. In order to do so, single cell sorting techniques must be employed. These techniques, though effective, are time consuming and expensive. For this reason, no large-scale analyses have been done on the immune repertoires using these techniques. In this study, we propose a novel method for linking the two TCR chain sequences from an individual cell. DNA origami nanostructure technology is employed to capture and bind the TCRγ and TCRδ chain mRNA inside individual cells using probe strands complementary to the C-region of those sequences. We then use a dual-primer RT and ligation molecular strategy to link the two sequences together. The result is a single amplicon containing the CDR3 region of the TCRγ and TCRδ. This amplicon can then be easily PCR amplified using sequence specific primers, and sequenced. DNA origami nanostructures offer a rapid, cost-effective method alternative to conventional single cell sorting techniques, as both TCR mRNA can be captured on one origami molecule inside a single cell. At present, this study outlines a proof-of-principle analysis of the method to determine its functionality. Using known TCRγ and TCRδ sequences, the DNA origami and RT/PCR method was tested and resulting sequence data proved the effectiveness of the method. The original TCRγ and TCRδ sequences were linked together as a single amplicon containing both CDR3 regions of the genes. Thus, this method can be employed in further research to elucidate the γδ T cell repertoire. This technology is also easily adapted to any gene target or cell type and therefore presents a large opportunity to be used in other immune repertoire analysis and other immunological studies (such as the rapid identification and subsequent production of antibodies).
ContributorsPoindexter, Morgan Elizabeth (Author) / Blattman, Joseph (Thesis director) / Yan, Hao (Committee member) / Schoettle, Louis (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
Patients who are infected with the human immunodeficiency virus (HIV) and who remain adherent to their highly active antiretroviral treatment (HAART) regimen are likely to achieve good virologic control over significant periods of time. Children who start with a low CD4 percentage (below 15%) are associated with adverse clinical outcomes and the risk of never increasing their CD4 counts to normal functioning levels. While adherent adult HIV patients have been studied frequently, this was a retrospective chart study that aimed to describe the immune reconstitution pattern for up to 16 years in virologically controlled pediatric patients who had been or who are currently being treated at the Bill Holt Clinic at Phoenix Children's Hospital. In the preliminary study, 35 patients met criteria for inclusion and three years later for this extension study 7 more were added while 17 of the initial patients were followed further because they have remained in care and virologically controlled. All 28 patients who achieved 5 years of viral suppression were >25% CD4. All 8 patients who achieved 12 years of viral suppression were >31% CD4. All patients who achieved 16 years of viral suppression were >41% CD4. After 12 years, the 8 patients who maintained viral suppression all had absolute CD4 counts of over 600 cells and additionally each had CD4/CD8 ratios greater than 1. Overall, the data shows immune system normalization for up to 16 years, although CD4/CD8 ratios improved but never completely normalized. Some limitations include a small sample size and missing data points due to laboratory testing errors or the lack of technology in different countries to test for CD8 cells. These findings suggest that children who remain adherent to HAART can experience ongoing immune healing for up to 16 years. This may provide additional incentive to providers and caretakers to encourage adherence and maximize long-term immune competence in HIV positive children.
ContributorsRichards, Anne Elizabeth (Author) / Wachter, Rebekka (Thesis director) / Blattman, Joseph (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor) / School of Human Evolution and Social Change (Contributor)
Created2015-05
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 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.
ContributorsRoesler, Alexander Scott (Author) / Anderson, Karen (Thesis director) / Blattman, Joseph (Committee member) / School of Molecular Sciences (Contributor) / School of Mathematical and Statistical Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Viral infections are a significant cause of disease in humans. While some viral diseases have been eliminated, many more continue to infect millions. Viral infections are challenging to treat because viruses use host cell machinery to replicate, so it is difficult to develop drugs that can target viruses. Normally, the host’s immune system is capable of destroying the virus, but during chronic infections it becomes exhausted and T cells lose their effector functions necessary for the clearance of the virus. IL-2 can help relieve this exhaustion, but causes toxicity to the body. In mice infected with chronic LCMV, IL-2 administration causes death due to pulmonary hemorrhage. CD4 deficient mice were infected with chronic LCMV and then dosed with IL-2 and survived, but mice that were deficient for CD8 T cells died, indicating that toxicity was mediated by CD8 T cells. CD8 T cells can kill infected host cells directly by producing perforin, or can produce cytokines like IFN-γ and TNF to further activate the immune system and mediate killing. Mice that were deficient in perforin died after IL-2 administration, as well as mice that were deficient in IFN-γ. Mice deficient in TNF, however, survived, indicating that TNF was mediating the toxicity in response to IL-2. There are two different receptors for TNF, p55 and p75. p55 is known as TNFR1 and has been implicated in apoptosis of virally infected cells. P75 is known as TNFR2 and is associated more with inflammation in response to infection. My hypothesis was that if TNFR2 was knocked out, infected mice would survive IL-2 dosing. When single knockouts of TNFR1 and 2 were used in an experiment however, it was found that either receptor is capable of mediating toxicity, as both experimental groups failed to survive. This is relevant to current IL-2 therapies because there is no way to eliminate a single receptor in order to reduce toxicity. Further studies exploring the anti-viral capabilities of IFN-γ are suggested.
ContributorsJarvis, Jordan Alisa (Author) / Blattman, Joseph (Thesis director) / Denzler, Karen (Committee member) / McAfee, Megan (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2014-05
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 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.
ContributorsHarris, Maryl (Author) / Blattman, Joseph (Thesis director) / Scotch, Matthew (Committee member) / Luna, Evelyn (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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 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.
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.
ContributorsDebray, Hannah Zara (Co-author) / Debray, Hannah (Co-author) / Blattman, Joseph (Thesis director) / Jurutka, Peter (Committee member) / Manhas, Kavita (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
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 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.
ContributorsVale, Nolan Richard (Author) / Anderson, Karen (Thesis director) / Blattman, Joseph (Committee member) / Department of Psychology (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
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 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.
ContributorsArnold, Emily (Author) / Kim, Suwon (Thesis director) / Blattman, Joseph (Thesis director) / Mason, Hugh (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
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 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.
ContributorsReed, Abigail Elizabeth (Author) / Blattman, Joseph (Thesis director) / Glenn, Honor (Committee member) / Schoettle, Louis (Committee member) / School of Life Sciences (Contributor) / W.P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Since Metastatic Osteosarcoma is unresponsive to most of the current standards of care currently available, and yields a survival rate of 20%, it is pertinent that novel approaches to treating it be undertaken in scientific research. Past studies in our lab have used a The Immune Blockade Therapy, utilizing α-CTLA-4 and α-PD-L1 to treat mice with metastatic osteosarcoma; this resulted in 60% of mice achieving disease-free survival and protective immunity against metastatic osteosarcoma. 12 We originally wanted to see if the survival rate could be boosted by pairing the immune blockade therapy with another current, standard of care, radiation. We had found that there were certain, key features to experimental design that had to be maintained and explored further in order to raise survival rates, ultimately with the goal of reestablishing the 60% survival rate seen in mice treated with the immune blockade therapy. Our results show that mice with mature immune systems, which develop by 6-8 weeks, should be used in experiments testing an immune blockade, or other forms of immunotherapy, as they are capable of properly responding to treatment. Treatment as early as one day after should be maintained in future experiments looking at the immune blockade therapy for the treatment of metastatic osteosarcoma in mice. The immune blockade therapy, using α-PD-L1 and α-CTLA-4, seems to work synergistically with radiation, a current standard of care. The combination of these therapies could potentially boost the 60% survival rate, as previously seen in mice treated with α-PD-L1 and α-CTLA-4, to a higher percent by means of reducing tumor burden and prolonging length of life in metastatic osteosarcoma.
ContributorsLabban, Nicole (Author) / Blattman, Joseph (Thesis director) / Appel, Nicole (Committee member) / Barrett, The Honors College (Contributor)
Created2017-05