Immunization with the malaria heat shock like protein hsp70-1 enhances transmission to the mosquito

Mosquitoes fed on mice infected with Plasmodium yoelii after an immunization with the i72 recombinant form of the heat shock protein hsp70-1 developed significantly more oocysts than mosquitoes fed on controls. This effect was due to a marked increase in the relative numbers of gametocytes during the early stages of infection. A comparison of blood-induced and sporozoite-initiated infection showed that these gametocytes were derived from merozoites released from the liver. The stimulus for increased gametocyte production is unknown but is likely to be linked with antibody-dependent cellular cytotoxicity and associated cytokine responses.