A highly effective vaccine against malaria is urgently needed, with leading vaccination strategies involving the induction of protective antigen-specific CD8<sup>+</sup> T-cells via heterologous prime-boost viral vector immunization, targeting primarily the pre- erythrocytic liver stages of the Plasmodium falciparum lifecycle. To date, the greatest immunogenicity has been obtained through a heterologous prime boost regimen, where vaccination with an Adenoviral vector is followed 8 weeks later by a Modified Vaccinia Ankara virus (MVA) boost. Experimental work directed at providing a greater understanding of CD8<sup>+</sup> T-cell memory responses induced by Ad-MVA vaccinations lead to the development of a novel vaccine strategy aimed at priming CD8<sup>+</sup> T-cells in the periphery and subsequently targeting them to hepatic tissue with protein loaded poly(lactic- co-glycolic acid) nanoparticles or recombinant viral vectors. Durable Ag-specific CD8+ T- cells exhibiting a phenotype of tissue-resident memory T-cells were generated in the liver, with a ten-fold increase over the conventional heterologous vector regimen. Importantly, in P. berghei sporozoite challenge models of liver-stage malaria, this strategy was found to result in unprecedented levels of sterile protection across multiple clinically relevant antigens and mouse strains. This prime and target immunization strategy for liver-stage malaria may provide a novel general approach for prevention or immunotherapy against other hepato-trophic pathogens.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:757852 |
| Date | January 2018 |
| Creators | Gola, Anita |
| Contributors | Germain, Ron ; Hill, Adrian ; Spencer, Alex |
| Publisher | University of Oxford |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://ora.ox.ac.uk/objects/uuid:4b1ce436-316f-43da-bacf-3b1e178f2f40 |
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