Search Results

1. Watson, Quentin Progress Against a Neglected Nightmare: An Evaluation of Plasmodium vivax's Invasion into Erythroid Lineage Cells

Doctor of Philosophy, Case Western Reserve University, 2025, Pathology

Plasmodium vivax induces blood stage infections by invading red blood cells (RBCs) using the Duffy (Fy) blood group antigen system. Individuals with the Fy blood group-positive alleles (FY*A and/or FY*B) are susceptible to infection, while Fy-negative (null) individuals with the erythrocyte silent, ES, allele (FY*AES and FY*BES) show resistance. Recent studies challenge this paradigm by reporting that Fy null populations across sub-Saharan Africa show incidences of P. vivax infection. In addition, our recent breakthrough discovery in Cell Host Microbe demonstrates Fy “null” cells may in fact express the Fy protein. Studies suggest that sites of hematopoiesis, such as the bone marrow or spleen, may act as a biological niche for P. vivax invasion into reticulocytes (the parasite's preferred target cells), but this has not been substantiated in vivo. To investigate this, a reliable culturing protocol and method of assessment is required. Research shows that culturing P. vivax in vitro is not only challenging, but impossible on a long-term scale, necessitating more innovative methods. We demonstrate that human bone marrow can be utilized to culture P. vivax and propagate the parasite on a long-term basis (over 1 year) for a series of experiments. To address our limitations, we have introduced the more easily cultured P. knowlesi (the closest related Plasmodium species to P. vivax) that has been genetically modified to replace its endogenous Fy binding protein (DBP) orthologue with PvDBP to create a transgenic parasite, PkPvDBPOR. Using this model, we evaluated the culture under different perturbations (e.g. Fy-specific antibodies) and discovered low level in vitro invasion of Fy null recipient cells.

Committee: Peter Zimmerman (Advisor); Brian Cobb (Committee Chair); Nicholas Ziats (Committee Member); Christopher King (Committee Member); Jürgen Bosch (Committee Member) Subjects: Biology; Biomedical Research; Immunology; Microbiology; Parasitology

2. Molina-RodrÃguez, Aurea Evaluation of an indirect hemagglutination technique for the detection of antibodies to Plasmodium gallinaceum /

Master of Science, The Ohio State University, 1969, Graduate School

Committee: Not Provided (Other) Subjects:

3. Pearson, Gary Serological studies of chickens infected with Plasmodium gallinaceum /

Master of Science, The Ohio State University, 1965, Graduate School

Committee: Not Provided (Other) Subjects:

4. Seed, Thomas Autoimmune reactions in chickens with plasmodium gallinaceum infection : the isolation and characterization of a lipid from trypsinized erythrocytes which reacts with serum from acutely infected chickens /

Master of Science, The Ohio State University, 1969, Graduate School

Committee: Not Provided (Other) Subjects:

5. Malachin, Alyssa IgG Isotypes by qPCR and High Resolution Melting from cDNA

Master of Sciences, Case Western Reserve University, 2024, Pathology

Malaria caused by the Plasmodium vivax parasite is a leading cause of disease burden in many tropical and subtropical parts of the world. Infection leads to the generation of antibodies specific to parasite proteins, such as apical membrane antigen 1 (AMA1). This ligand plays a role in invasion of reticulocytes by binding of the rhoptry neck (RON) complex, which is composed of RON proteins. This complex is inserted by the parasite into the cell surface. In malaria infections, IgG1 and IgG3 isotype frequencies are increased. These isotypes can activate complement or bind Fc receptors to initiate effector functions. As part of a project that isolates cDNA from individual PvAMA1- specific IgG expressing B cells, we aim to develop a rapid method to identify the IgG subclass from these B cells to provide a more comprehensive view of immunoglobulin generation in these individuals.

Committee: Neena Singh (Committee Chair); Jürgen Bosch (Committee Member); Christopher King (Committee Member) Subjects: Immunology; Molecular Biology; Parasitology; Pathology

6. Olvany, Jasmine Detection of Species-Specific Plasmodium Infection Using Unmapped Reads From Human Whole Genome Sequences

Doctor of Philosophy, Case Western Reserve University, 2023, Genetics

Whole genome sequencing (WGS) is an ever expanding tool in the field of genetics, and is widely used to characterize human genetic variation. There are multiple large-scale sequencing studies being conducted today worldwide, like All of Us, Three Million African Genomes, and GenomeAsia 100k. The addition of these diverse datasets alone can be transformative to our understanding of genetics, but the increase in the diversity of populations sampled also has the potential to reveal additional and novel information relevant to health and disease. Specifically, whole genome sequence (WGS) analyses of DNA from human whole blood may be able to capture genetic variation in other species that can affect both individual and public health. The research detailed in this dissertation aims to illustrate the utility of human WGS data for infectious disease, by showing that the malaria causing parasite Plasmodium can be sensitively detected from unmapped reads (UMRs) from WGS data. Malaria has a significant global health burden, and elimination of the disease has been a goal since the 1950s. Recently, there have been roadblocks in the progress of malaria elimination that can only be resolved through additional research efforts. Development of this detection methodology could be the tool required to better define the parasite population, identify problematic populations, and solve the roadblocks limiting elimination success.

Committee: Thomas LaFramboise Ph.D. (Committee Chair); Scott Williams Ph.D. (Advisor); Peter Zimmerman Ph.D. (Advisor); Dana Crawford Ph.D. (Committee Member); Arlene Dent MD, Ph.D. (Committee Member) Subjects: Biomedical Research; Epidemiology; Genetics; Parasitology

7. Yadavalli, Raghavendra TRAFFICKING AND BIOCHEMICAL CHARACTERIZATION OF PLASMODIUM FALCIPARUM MAURER'S CLEFT TWO TRANSMEMBRANE PROTEIN

Doctor of Philosophy in Regulatory Biology, Cleveland State University, 2018, College of Sciences and Health Professions

Plasmodium falciparum virulence proteins and molecules required for assembly of the knobs used for cytoadherence are exported through the Maurer's clefts which are formed in the erythrocyte cytoplasm immediately following merozoite invasion into the erythrocyte host cell. Proteins participating in knob formation, cytoadherence or immune evasion include variant-surface antigens (VSAs) that are trafficked alone or chaperoned by other parasite proteins through the Maurer's clefts. In this study, recombinant PfMC-2TM was expressed using HeLa based in vitro human cell free expression system. Further, the stage specific expression, trafficking, solubility and topology of endogenous PfMC-2TM in the parasite and erythrocyte cytoplasm was investigated in 3D7 and FC-27 strains of P. falciparum. Detailed cell biological and biochemical characterizations were performed to identify the mode of PfMC-2TM export from the parasite to erythrocyte cytoplasm. Following Brefeldin A (BFA) treatment of parasites, PfMC-2TM traffic was evaluated using immunofluorescence and western blotting with antibodies reactive with PfMC-2TM. Our data shows that PfMC-2TM is sensitive to BFA treatment in the ring and trophozoite stage. Permeabilization of infected erythrocytes with streptolysin O (SLO) and saponin, showed that the N and C-termini of PfMC-2TM are exposed to the erythrocyte cytoplasm with the central portion of the protein protected in the MC membranes. PfMC-2TM was expressed as early as 4 h post invasion (hpi), was tightly colocalized with Maurer's cleft resident protein REX-1 and trafficked to the erythrocyte membrane without a change in solubility. PfMC-2TM associates with the infected erythrocyte membrane as an integral membrane protein and is seen to be transiently exposed on the infected red blood cell surface. PfMC-2TM remains insoluble upon association with the MC and erythrocyte membrane, suggestive of protein-lipid interactions with membranes of the MC and erythrocyte. PfMC-2TM i (open full item for complete abstract)

Committee: Tobili Sam-Yellowe (Advisor); Girish Shukla (Committee Member); Roman Kondratov (Committee Member); Bin Zhang (Committee Member); Severson Aaron (Other); Ronald Blanton (Other) Subjects: Biochemistry; Biology; Parasitology

8. Willie, Nigani Plasmodium falciparum Histidine-rich Protein 2 Gene Variation and Malaria Detection in Madagascar and Papua New Guinea

Master of Sciences, Case Western Reserve University, 2018, Biology

Plasmodium falciparum histidine-rich protein 2 (PfHRP2) forms the basis of many current malaria rapid diagnostic tests (RDTs). However, parasites lacking the pfhrp2 gene do not express the PfHRP2 protein and are, therefore, not identifiable by PfHRP2-detecting RDTs. In this study, the performance of the SD Bioline Malaria Ag P.f/Pan RDT together with pfhrp2 variation in Madagascar was evaluated. The study also evaluated pfhrp2 gene variation in PNG. Genomic DNA isolated from patient blood samples from Madagascar (n = 260) and PNG (n = 169) were subjected to molecular detection (18S rRNA PCR, followed by post-PCR LDR-FMA) for the identification of Plasmodium spp. infections. PCR amplification of the pfhrp2 gene, sequencing and gene analysis enabled studying of gene variation. PCR diagnosis showed that 28.8% (75/260) in Madagascar and 81.1% (137/169) in PNG had Plasmodium infections. 94.6% (71/75) and 91.2% (125/137), of the infections were P. falciparum in Madagascar and PNG, respectively. Compared to molecular detection, the sensitivity and specificity of the RDT (in Madagascar) for P. falciparum detection were 87% and 89%, respectively. From randomly selected pfhrp2 gene-positive samples, 16 pfhrp2 gene sequences from Madagascar and 18 pfhrp2 gene sequences from PNG were generated. Although extensive variations of the pfhrp2 gene were observed in both countries, this study showed that there was no indication of pfhrp2 deletion. The study also did not observe a clear correlation between pfhrp2 sequence structure and RDT detection rates. Although the absence of pfhrp2 deletion from the samples screened here is encouraging, continued monitoring of the efficacy of RDTs currently used in Madagascar and PNG is warranted.

Committee: Peter Zimmerman A. (Advisor); Daniel Tisch J. (Committee Member); Emmitt Jolly R. (Committee Member); Hillel Chiel (Committee Chair) Subjects: Biology; Epidemiology; Genetics; Molecular Biology; Parasitology