Biology ETDs

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This study was done to test the efficacy of 3 malarial vaccine preparations using merozoite, schizont, and French press antigens (Ags). The experiment utilized the Plasmodium knowlesi - rhesus monkey system. In conjunction with this study the lymphocyte transformation test and the solid phase radioimmunoassay (RIA) were evaluated as in vitro assays for protective cell-mediated and humoral immune responses, respectively. Delayed dermal hypersensitivity reactions to P. knowlesi and the proportion of B and T lymphocytes were also examined by rosette formation. Lymphocytes from Ag-immunized monkeys showed greater in vitro blastogenic responses to P. knowlesi French press Ag than did lymphocytes from control monkeys injected with phosphate buffered saline (PBS) or Freund's complete adjuvant (FCA). Lymphocytes from Ag-immunized monkeys had only slightly higher mitogenic responses to Concanavalin A (Con A) and phytohemagglutinin (PHA) than did their control counterparts. Lymphocyte responses to Ag, Con A, and PHA dropped following challenge and later rose again to prechallenge levels. Blastogenic or mitogenic lymphocyte responses could not be correlated with survival or delay of death following parasite challenge. Anti-P. knowlesi antibody levels were measured in the RIA. Antibody levels were increased following immunization with all 3 antigen preparations with the highest concentrations seen in the merozoite and French press Ag groups. The presence of RIA-measurable anti­body did not insure survival from parasite challenge in all cases. Delayed hypersensitivity reactions to the intradermal {i.d.) injection of P. knowlesi French press Ag were measured and those reactions >5 mm in diameter were considered positive. Fifteen of 24 vaccinated monkeys gave positive reactions and 7 of those survived parasite challenge. There was positive correlation between the day of death and the size of the reaction sites at 24 hrs. The presence of a positive skin reaction correlated with survival longer than 12 days. The presence of positive skin reactions did not correlate with absolute survival. The formation of erythrocyte (E) rosettes by T lymphocytes and erythrocyte-antibody-complement (EAC) rosettes by B lymphocytes was examined in the monkeys at intervals during the study. The proportion of B cells remained the same throughout the study in all groups. The proportion of T cells remained the same during the immunization period and decreased 3 weeks after challenge. Coinciding with the decrease in T cells was an increase in null cells.



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Degree Name


Level of Degree


Department Name

UNM Biology Department

First Committee Member (Chair)

Donald Walter Duszynski

Second Committee Member

Gary H. Campbell

Third Committee Member

Steven Bret Snyder

Fourth Committee Member

Paul Richard Kerkof

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Biology Commons