Matching Items (27)
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- All Subjects: Immunology
- Creators: School of Life Sciences
- Status: Published
Description
Moraxella catarrhalis is a gram negative commensal bacteria that is a primary cause of otitis media in infants and severe exacerbations of COPD in adults. M. catarrhalis treatment has become increasingly difficult and expensive over the past half-century due to the emergence of beta-lactamase producing strains. There are currently no vaccines available to protect against infections. In this paper, we propose a transcriptomics-based approach for identifying potential vaccine targets. Additionally, a novel method was used to create bacterial vaccine polypeptides composed of sequence conserved peptides secreted through the outer membrane. Polypeptides were tested for immunogenicity and protective capacity in mice. We show that relative abundance of outer membrane proteins does not correlate with immunogenicity. We also show promising results for polypeptide protection in a mouse pulmonary clearance model.
ContributorsRobinson, Aspen Grace (Author) / Stull, Terrence (Thesis director) / Whitby, Paul (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
Purinergic receptors sense extracellular nucleotide DAMPs such as ATP and adenosine, which are expressed in high concentrations in the tumor microenvironment (TME). A2AR, an adenosine receptor that is expressed on both T cells and tumor cells, promotes immunosuppression. However, the impact of the TME on changes in purinergic receptor expression on CD8 T cells, as well as the overall dynamic between A2AR expression and tumor control, have not been clearly elucidated. Using in vitro co-culture experiments and in vivo murine tumor models, we found that A2AR is significantly upregulated on effector, tumor-infiltrating CD8 T cells. This upregulation was independent of the hypoxia, which we identified via inhibition of HIF1A. We found that this upregulation was partially dependent on CD8 T cell-tumor contact, but independent of cognate antigen recognition, by using transwell co-cultures, as well as combinations of different transgenic lines of CD8 T cells and tumor cells. We confirmed this observation in vivo using transfer of activated OTI cells into B16.OVA-bearing mice. Ultimately, we observed that the upregulation depended on inhibitory receptors such as Tim3 via the antibody blockade of Tim3. Using CRISPR/Cas9-mediated knockout of A2AR on activated CD8 T cells, we found that tumor-bearing mice receiving A2AR knockout CD8 T cells had increased tumor control. Taken together, these results suggest that inhibitory receptor-dependent, TCR-independent signals in the TME promotes upregulation of A2AR on CD8 T cells, leading to impairment of CD8 T cell-mediated tumor control.
ContributorsZhou, Maggie (Author) / Borges da Silva, Henrique (Thesis director) / Borges Florsheim, Esther (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Economics Program in CLAS (Contributor)
Created2022-12
P2RX7 promotes a pro-memory signature in effector CD8+ T cells dependent on Zeb2 negative regulation
Description
Memory CD8+ T cells protect against secondary viral infections. They develop and maintain exclusively in circulation (e.g. central memory - Tcm) or are excluded from re-circulation (resident memory - Trm). The extracellular ATP receptor P2RX7 promotes both Tcm and Trm generation. High (P2RX7hi) P2RX7-expressing early effector cells show survival, memory and pluripotency genes. Conversely, many terminal effector (TE) and apoptosis genes are upregulated in low (P2RX7lo) P2RX7-expressing cells. Among these genes is the zinc-finger transcriptional repressor Zeb2, which promotes TE differentiation at the expense of the memory cell pool. Given that Zeb2 was higher in P2RX7lo early effector cells, we postulated that Zeb2 ablation would allow P2RX7-deficient CD8+ T cells to skew towards memory subsets. To test this, we used RNP-based CRISPR-Cas9 to knockout Zeb2 in wild type or P2RX7-deficient P14 cells. At the memory timepoint, Zeb2 ablation led to a rescue of the ability of P2RX7-deficient cells to differentiate into the CD62L+ Tcm and CD69hiCD103hi Trm subsets, as well as increase the population of each. Our data suggest that P2RX7 imprints a pro-memory signature that is, to some extent, dependent on the negative regulation of Zeb2.
ContributorsVan Dijk, Sarah (Author) / Holechek, Susan (Thesis director) / Borges da Silvs, Henrique (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Molecular Sciences (Contributor) / School of International Letters and Cultures (Contributor)
Created2021-12
ContributorsVan Dijk, Sarah (Author) / Holechek, Susan (Thesis director) / Borges da Silvs, Henrique (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2021-12
ContributorsVan Dijk, Sarah (Author) / Holechek, Susan (Thesis director) / Borges da Silvs, Henrique (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2021-12
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
The amphibian pathogen Ambystoma Tigrinum Virus (ATV) has been an important topic of study within the amphibian community since its discovery. ATV threatens many salamander populations across the US, including those in east-central and southeast Arizona. These populations remain at risk since there are no treatments available. In this thesis, a novel method of inactivation is tested to produce a vaccine with the aim of safely eliciting an immune response within the salamander host. This novel form of inactivation has been tested on several human pathogens but has yet to be used on amphibian pathogens. It has the potential to revolutionize our traditional approach to inactivating viruses. After laser treatment, viral plaque assays suggested that inactivated ATV ceased to grow completely, pointing to the possibility of creating a vaccine. Animal challenge trials were conducted with 60 juvenile Ambystoma tigrinum, but surprisingly there was no protective effect from viral inactivation. Further study is needed to clarify why in vitro and in vivo tests of viral inactivation produced contradictory results.
ContributorsVazquez, Luis Ernesto (Author) / Collins, James (Thesis director) / Tsen, Kong-Thon (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
Immunology, the study of the immune system and its ability to distinguish self from non-self, is a rapidly advancing sector of molecular biology. Cancer, being host derived, provides a difficult challenge for immune cells to distinguish it from normal tissue. The historic treatment of cancer has had three main methods: radiation, chemotherapy, and surgery (1). Due to recent advancements in understanding the regulatory role of adaptive immunity against cancer, researchers have been attempting to engineer therapies to enhance patients’ immunities against their cancer. Immunotherapies, both passive and active, demonstrate potential for combating many diseases. Passive immunization provides temporary protection against a pathogen, whereas active immunization teaches the patient’s system to respond to the antigen independently, giving life-long immunity. Passive immunization, generally, is a much more expensive method of providing immunity and is commonly used in emergency situations. Anti-venom, for example, uses antibodies grown in lab to neutralize venom. Examples of active immunization are vaccines, which mimic the wild-type pathogen in a way that elicits an immune response, specifically naïve lymphocyte activation and maturation into memory lymphocytes. In terms of cancer therapy, both passive and active immunization are being tested for efficacy (2).
ContributorsMarquardt, Charles Andrew (Author) / Anderson, Karen S. (Thesis director) / Mason, Hugh S. (Committee member) / Lake, Douglas F. (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
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