Last Updated

08 Jan 2019

ASTMH 2016, Caio Martinelle França: "Mosquito Midgut FREP1 is a potential universal malaria transmission-blocking vaccine"

In collaboration with ASTMH, Image Audiovisuals, and session presenters, MESA brings you this webcast from the 65th ASTMH annual meeting in Atlanta, November 2016.

Title: "Mosquito Midgut FREP1 is a potential universal malaria transmission-blocking vaccine"

Speaker: Caio Martinelle França, University of Oklahoma, United States

Session information:  Scientific Session 34: Malaria: Vaccines - Diverse Approaches

Monday, 14 November, 1:45 - 3:30pm, Marriott - Marquis C


Malaria remains a devastating disease. Transmission-blocking vaccines (TBVs) have been recently considered as a promising approach for the elimination and eradication of malaria. We recently discovered a mosquito midgut protein FREP1 that facilitates parasite transmission through direct binding to parasites and it is easily accessible to antibodies co-ingested with blood. Here, we demonstrated that anti-FREP1 antibodies blocked transmission of multiple Plasmodium species (Plasmodium bergheiPlasmodium vivax, and P. falciparum) to multiple Anopheles species (Anopheles gambiae and A. dirus)Sequence comparison of FREP1 orthologs found that a fibrinogen-like (FBG) domain is highly conserved (>90% identity) among Anopheles species from different continents, while the sequence similarity between FBG and human fibrinogens is only about 10%. Immunization of mice with purified recombinant FREP1 shows no significant difference of alanine aminotransferase activity between anti-FREP1 serum and the pre-immune serum. Moreover, the anti-FREP1 serum did not show any cross-reactions with human fibrinogens. Thus, FREP1 is non-toxic or unlikely to cause autoimmune response in mammals. Notably, mice immunized with purified FBG effectively blocked P. berghei transmission (82.1% and 70.1% blockade) to An. gambiae in two independent bioassays respectively. Anti-FREP1 serum from the immunized mice also blocked over 90% infection of P. falciparum in standard membrane-feeding assays (SMFA). In summary, our data support that FREP1 is a promising universal TBV antigen to block the transmission of multiple Plasmodium species to multiple Anopheles species.


University of Oklahoma, USA

Date Published