Comparative functional potency of DNA vaccines encoding Plasmodium falciparum transmission blocking target antigens Pfs48/45 and Pfs25 administered alone or in combination by in vivo electroporation in rhesus macaques

• Published in: Vaccine Vol. 35; no. 50; pp. 7049 - 7056
• Main Authors: Datta, Dibyadyuti, Bansal, Geetha P., Grasperge, Brooke, Martin, Dale S., Philipp, Mario, Gerloff, Dietlind, Ellefsen, Barry, Hannaman, Drew, Kumar, Nirbhay
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier Ltd 15-12-2017; Elsevier Limited
• Subjects: Animals; Antibodies; Antibodies, Protozoan - blood; Antigens; Blocking antibodies; Clinical trials; Combination vaccine; Deoxyribonucleic acid; Disease transmission; DNA; DNA vaccine; DNA vaccines; DNA, Protozoan - administration & dosage; Electroporation; Epitopes; Female; Fertilization; Gene sequencing; Immunity; Immunization Schedule; Immunogenicity; In vivo methods and tests; Laboratory animals; Macaca mulatta; Malaria; Malaria vaccine; Male; Membrane Glycoproteins - genetics; Membrane Glycoproteins - immunology; Mosquitoes; Nucleotide sequence; Parasites; Plasmids; Plasmids - administration & dosage; Plasmodium falciparum; Plasmodium falciparum - genetics; Plasmodium falciparum - immunology; Primates; Proteins; Protozoan Proteins - genetics; Protozoan Proteins - immunology; Target antigen; Transmission; Treatment Outcome; Vaccines; Vaccines, DNA - administration & dosage; Vaccines, DNA - genetics; Vaccines, DNA - immunology; Vector-borne diseases; Zygotes; DNA vaccine; Combination vaccine; Mosquitoes; Target antigen; Malaria vaccine; Transmission
• ISSN: 0264-410X; 1873-2518
• DOI: 10.1016/j.vaccine.2017.10.042

Antibodies recognizing conformational epitopes in Pfs48/45, an antigen expressed on the surface of Plasmodium falciparum gametes and zygotes, have firmly established Pfs48/45 as a promising transmission blocking vaccine (TBV) candidate. However, it has been difficult to reproducibly express Pfs48/45 in a variety of recombinant expression systems. The goal of our studies was to evaluate functional immunogenicity of Pfs48/45 using DNA vaccine format in rhesus macaques. An additional goal was to ensure that when used in combination with another malarial antigen, specific immunity to both antigens was not compromised. For testing combination vaccines, we employed Pfs25 DNA plasmids that have previously undergone evaluations in rodents and nonhuman primates. Pfs25 is expressed on the surface of parasites after fertilization and is also a lead TBV candidate. DNA plasmids based on codon-optimized sequences of Pfs48/45 and Pfs25 were administered by in vivo electroporation, followed by a final recombinant protein boost. Our studies demonstrate that Pfs48/45 encoded by DNA plasmids is capable of inducing potent transmission blocking antibody responses, and such transmission blocking immune potency of Pfs48/45 was not compromised when tested in combination with Pfs25, These findings provide the evidence in favor of further studies on Pfs48/45 and Pfs25, either alone or in combination with other known malaria vaccine candidates for developing effective vaccines capable of interrupting malaria transmission.