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Immunol."],"abstract":"<jats:p>PfRipr is a highly conserved asexual-blood stage malaria vaccine candidate against <jats:italic>Plasmodium falciparum<\/jats:italic>. PfRipr5, a protein fragment of PfRipr inducing the most potent inhibitory antibodies, is a promising candidate for the development of next-generation malaria vaccines, requiring validation of its potential when formulated with adjuvants already approved for human use. In this study, PfRipr5 antigen was efficiently produced in a tank bioreactor using insect High Five cells and the baculovirus expression vector system; purified PfRipr5 was thermally stable in its monomeric form, had high purity and binding capacity to functional monoclonal anti-PfRipr antibody. The formulation of purified PfRipr5 with Alhydrogel<jats:sup>\u00ae<\/jats:sup>, GLA-SE or CAF<jats:sup>\u00ae<\/jats:sup>01 adjuvants accepted for human use showed acceptable compatibility. Rabbits immunized with these formulations induced comparable levels of anti-PfRipr5 antibodies, and significantly higher than the control group immunized with PfRipr5 alone. To investigate the efficacy of the antibodies, we used an <jats:italic>in vitro<\/jats:italic> parasite growth inhibition assay (GIA). The highest average GIA activity amongst all groups was attained with antibodies induced by immunization with PfRipr5 formulated with CAF<jats:sup>\u00ae<\/jats:sup>01. Overall, this study validates the potential of adjuvanted PfRipr5 as an asexual blood-stage malaria vaccine candidate, with PfRipr5\/CAF<jats:sup>\u00ae<\/jats:sup>01 being a promising formulation for subsequent pre-clinical and clinical development.<\/jats:p>","DOI":"10.3389\/fimmu.2022.1002430","type":"journal-article","created":{"date-parts":[[2022,10,27]],"date-time":"2022-10-27T05:22:28Z","timestamp":1666848148000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":10,"title":["A novel asexual blood-stage malaria vaccine candidate: PfRipr5 formulated with human-use adjuvants induces potent growth inhibitory antibodies"],"prefix":"10.3389","volume":"13","author":[{"given":"Eizo","family":"Takashima","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hikaru","family":"Nagaoka","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ricardo","family":"Correia","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Paula M.","family":"Alves","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ant\u00f3nio","family":"Rold\u00e3o","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Dennis","family":"Christensen","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Jeffrey A.","family":"Guderian","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Akihisa","family":"Fukushima","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Nicola K.","family":"Viebig","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Hilde","family":"Depraetere","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Takafumi","family":"Tsuboi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1965","published-online":{"date-parts":[[2022,10,27]]},"reference":[{"key":"B1","volume-title":"World malaria report 2021","year":"2021"},{"key":"B2","doi-asserted-by":"publisher","first-page":"31","DOI":"10.1016\/S0140-6736(15)60721-8","article-title":"And safety of RTS,S\/AS01 malaria vaccine with or without a booster dose in infants and children in Africa: Final results of a phase 3, individually randomised, controlled trial","volume":"386","author":"SCTP. 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