Browsing by Subject "Comparative and molecular biosciences"
Now showing 1 - 7 of 7
Results Per Page
Sort Options
Item Derivation of lymphocytes from human induced pluripotent stem cells(2014-09) Ma, ChaoHuman pluripotent stem cells have the potential to produce essentially unlimited numbers of mature and functional blood lineage populations to study human hematopoiesis. Particularly, human induced pluripotent stem cells (hiPSCs) have the advantage to provide a source of autologous transplantable blood cell populations suitable for treatment of patient specific hematological diseases. This research aims to derive human lymphocytes from hiPSCs. There are three projects: The overall generation of human lymphocytes (B cell, T cell and NK cell) from hiPSCs is explored in Project I. In Project II and III, based on the derivation of NK cells, two human immunodeficiency disease models, both caused by specific somatic gene mutation, are established using human pluripotent stem cells. The ultimate goal of this research is to use hiPSCs to study the normal development of human lymphocytes in vitro, as well as model human immunodeficiency diseases by combining with gene therapy methods, thus providing a novel approach for immunotherapy. The hypothesis is that human lymphocytes can be derived from hiPSCs and this will enable the establishment of in vitro models to study human immunodeficiency diseases. Specific aims:1. To generate human lymphocytes from hiPSCs in vitro;2. To establish two human immunodeficiency disease models (X-SCID and WAS) through in vitro derivation of lymphocytes from hESCs/hiPSCs.Item Effect of oxygen on tumor cell vaccine.(2010-08) Toma, ShokoGliomas are the most common type of malignant brain tumor. Even with the recent progress in conventional therapies, the prognosis remains poor and development of effective immunotherapy is needed. Tumor vaccines using CpG and tumor lysate have been demonstrated as effective in glioma therapies. We hypothesized that tumor lysate grown in a physiologic 5 % O2 condition would increase immunogenicity compared to atmospheric 20 % O2 condition since glioma in situ has been demonstrated hypoxic; and hypoxic conditions can activate the danger signal to induce antitumor immunogenicity in addition to CpG. In this study, we characterized the immunogenicity of tumor lysate derived from 5 % O2 condition for the first time in comparison with 20 % O2 condition. Vaccination with lysate from 5 % O2 condition increased the numbers of several lymphocyte subsets at draining lymph nodes compared to the tumor lysate from 20 % O2 condition. Vaccination with lysate from 5 % O2 condition did not change the cytokine levels in the sera compared to the vaccination with lysate from 20 % O2. Tumor reactive antibody levels were increased with the amount of lysate used for vaccines; however, there was not a significant difference in antibody levels with 5 % O2 in comparison with 20 % O2. Lastly, using the tumor lysate from 5 % O2 condition had superior efficacy in inducing cytotoxicity against glioma compared to the tumor lysate from 20 % O2 condition. CD8+ T depletion showed that there were other cells that play a role in this cytotoxicity. Together, these data show that 5 % oxygen tumor lysate has distinct effects on immunogenicity compared to 20 % O2 lysate. These findings indicate a potential application in cancer treatment.Item Evaluation of potential risk factors of porcine reproductive and respiratory syndrome virus transmission.(2012-03) Baker, Seth R.Abstract summary not availableItem Isolation and characterization of Staphylococcus aureus from bulk tank milk from Minnesota dairy farms.(2011-08) Haran, Kumudhini PreethiAbstract summary not availableItem Phylogenetic and genomic characterization of porcine enterotoxigenic Escherichia coli(2011-08) Shepard, Sara MariaPorcine enterotoxigenic Escherichia coli (ETEC) is a significant pathogen of young pigs, causing considerable morbidity and mortality. While the known plasmidencoded virulence factors related to porcine ETEC infection have been well-studied, the chromosomal background of porcine ETEC has been largely understudied. Since chromosomal backgrounds and any chromosome-encoded virulence factors may directly or indirectly influence ETEC pathogenesis, they deserve attention. In this study, we utilized the first completed genome sequences of porcine ETEC to better understand porcine ETEC chromosomal content. We first examined the porcine ETEC chromosome by performing multilocus sequence analysis on 80 different porcine ETEC isolates implicated in neonatal and post-weaning diarrhea. We found that the porcine ETEC examined clustered into several specific lineages, suggesting the acquisition of porcine ETEC virulence plasmids into different E. coli chromosomal lineages on multiple occasions. These results also suggest that only certain chromosomal backgrounds support successful ETEC-related plasmid carriage. Patterns in resistance and virulence plasmid carriage were less clear, with plasmids of interest distributed widely among the isolates. Additionally, we used predictive software to identify putative surface-expressed proteins with predicted high antigenicity from the completed genome of UMNK88, a K88-positive porcine ETEC. The prevalence of these genes was examined in porcine ETEC strains and in commensal E. coli from healthy pigs. Genes found in ETEC significantly more often than in commensal E. coli include Antigen 43 precursor protein, tatD, and several other putative outer membrane or exported proteins.Item Prevalence of porcine circovirus Type 2 (PCV2) in the U.S. national swine herd(2014-08) Yan, YangPorcine circovirus associated-disease (PCVAD) is a set of different symptoms and diseases caused by PCV2 that causes significant economical lost in swine industry every year. To investigate the prevalence and vaccination status of PCV2 in US swine herd, a total amount of 2989 serum samples from 202 farms of 13 states of United States has been collected and tested serologically using both cap- and rep-specific indirect ELISA. My ELISA data shows PCV2 prevalence in US swine herd is fairly low (13%-27%), and has decreased during the past 5 years.Item Transcriptional regulation of Escherichiacoli modulated by multidrug resistance IncA/C plasmid.(2011-05) Fernández Alarcón, Claudia LissetteIncompatibility group A/C (IncA/C) plasmids have received recent attention for their broad host range and ability to confer resistance to multiple antimicrobial agents.Due to the potential spread of multidrug resistance (MDR) phenotypes from foodborne pathogens to human pathogens, the dissemination of these plasmids represents a public health risk. In this study, four animal-source IncA/C plasmids isolated from Escherichia coli were sequenced and analyzed, including isolates from commercial dairy cows, pigs and turkeys in the U.S. and Chile. These plasmids were initially selected because they either contained the floR andtetA genes encoding for florfenicol and tetracycline resistance, respectively, and/or the blaCMY-2gene encoding for extended spectrum β-lactamase resistance. Overall, sequence analysis revealed that each of the four plasmids retained a remarkably stable and conserved backbone sequence, with differences observed primarily within their accessory regions, which presumably have evolved via horizontal gene transfer events. Comparison of these plasmids with other available IncA/C plasmid sequences shed further light on the core and accessory elements of these plasmids in bacteria originating from commercial animal production environments.Specifically, our results suggest that the blaCMY-2 plasmid lineage appears to have derived from an ancestral IncA/C plasmid type harboring floR-tetAR-strAB and Tn21-like accessory modules. Evidence is mounting that IncA/C plasmids are widespread among enteric bacteria of production animals and these emergent plasmids have flexibility in their acquisition of MDR-encoding modules, necessitating further study to understand the evolutionary mechanisms involved in their dissemination and stability in bacterial populations. 2)Incompatibility group A/C (IncA/C) plasmids have received recent attention for their broad host range and ability to confer resistance to multiple antimicrobial agents.Due to the potential spread of multidrug resistance phenotypes from foodborne pathogens to human pathogens, the dissemination of these plasmids represents a public health risk. In this study, transcriptome analysis of the Escherichia coli chromosome was performed in response to acquisition of the IncA/C plasmid pAR060302 using RNA-Seq. In total, 109 genes were identified as being differentially expressed at least 2-fold or greater; 65 of which were significantly up-regulated (p < 0.05) and 44 of which were significantly down-regulated. The marRAB genes of the multiple antimicrobial resistance (mar) locus were among the most strongly up-regulated genes together with genes such as garPLRK-rnpB. Further analysis of the expression of the mar genes in response to pAR060302 acquisition was performed in several wild type strains, confirming that pAR060302 up-regulates the mar genes in natural E. coli hosts. Overall, this work confirms that acquisition of the IncA/C plasmid by a plasmidless host modulates a number of E. coli chromosomal genes. The most over-represented biological process that were related to the differentially expressed genes are mainly involved in function related to carbohydrate catabolic process, cell wall and membrane, transporter activity, and structural constituent of ribosome and succinate dehydrogenase activity. The phenotypic extent of such modulations is yet to be determined, but these modulations may contribute to the overall success of this emergent plasmid type among enteric bacterial populations.