Date of Award
Campus Access Thesis
Master of Science (MS)
Biotechnology and Biomedical Science
Colby A. Souders
Even more than a century after the discovery of the most severe malaria-causing parasite, Plasmodium falciparum, the disease still kills nearly 1 million people every year, many of which are children. Attempts to prevent infection and curb the prevalence of the disease have reduced infection rates in recent years; however, these interventions don’t prove to be reliable, long-term, prophylactic strategies. Resistance is developing to antimalarial drugs and a recently developed vaccine, RTS,S, only exhibited modest efficacy in clinical trials. Disease burden is enormous in endemic regions of the world. Consequently, a need for a pre-exposure prophylaxis still exists for travelers and residents in these areas of the world. Data from vaccine trials and individuals with acquired immunity suggest that a monoclonal antibody could prove to be a potent protection strategy against malaria. Circumsporozoite Protein (CSP), a plasmodium surface protein expressed during initial infection, was selected as a target for monoclonal antibody discovery and produced in a soluble form. Here I describe a flow cytometry-based methodology for identifying, isolating and genotyping CSP-specific memory B cells from a peripheral blood mononuclear cell (PBMC) population.
The PBMC samples were obtained from naturally infected children in Kenya and enriched for B cells. Heavy and light chain immunoglobulin (Ig) genes were PCR amplified from sorted CSP-specific memory B cells and cloned into expression vectors to produce recombinant antibodies in a mammalian expression cell line. Screening for CSP specificity and epitope mapping revealed a cross-reactive, CSP binding monoclonal antibody. Supporting data suggests that this antibody could prove to be a viable resource in the fight against malaria. I established a platform process for discovering and identifying CSP-specific antibodies from PBMC populations of previously infected individuals.
Nelson, Stuart C., "Discovery of Human Monoclonal Antibodies to Malaria Circumsporozite Protein from Single-Cell Sorted B Cells" (2017). Graduate Masters Theses. 434.