Immunopotentiation by Lymph-Node Targeting of a Malaria Transmission-Blocking Nanovaccine

Autor: Gregory P. Howard, Nicole G. Bender, Prachi Khare, Borja López-Gutiérrez, Vincent Nyasembe, William J. Weiss, Jerry W. Simecka, Timothy Hamerly, Hai-Quan Mao, Rhoel R. Dinglasan
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Frontiers in Immunology, Vol 12 (2021)
Druh dokumentu: article
ISSN: 1664-3224
DOI: 10.3389/fimmu.2021.729086
Popis: A successful malaria transmission blocking vaccine (TBV) requires the induction of a high antibody titer that leads to abrogation of parasite traversal of the mosquito midgut following ingestion of an infectious bloodmeal, thereby blocking the cascade of secondary human infections. Previously, we developed an optimized construct UF6b that elicits an antigen-specific antibody response to a neutralizing epitope of Anopheline alanyl aminopeptidase N (AnAPN1), an evolutionarily conserved pan-malaria mosquito midgut-based TBV target, as well as established a size-controlled lymph node targeting biodegradable nanoparticle delivery system that leads to efficient and durable antigen-specific antibody responses using the model antigen ovalbumin. Herein, we demonstrate that co-delivery of UF6b with the adjuvant CpG oligodeoxynucleotide immunostimulatory sequence (ODN ISS) 1018 using this biodegradable nanoparticle vaccine delivery system generates an AnAPN1-specific immune response that blocks parasite transmission in a standard membrane feeding assay. Importantly, this platform allows for antigen dose-sparing, wherein lower antigen payloads elicit higher-quality antibodies, therefore less antigen-specific IgG is needed for potent transmission-reducing activity. By targeting lymph nodes directly, the resulting immunopotentiation of AnAPN1 suggests that the de facto assumption that high antibody titers are needed for a TBV to be successful needs to be re-examined. This nanovaccine formulation is stable at -20°C storage for at least 3 months, an important consideration for vaccine transport and distribution in regions with poor healthcare infrastructure. Together, these data support further development of this nanovaccine platform for malaria TBVs.
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