Activity of Human Volunteer Sera to Candidate 'Plasmodium falciparum'Circumsporozoite Protein Vaccines in the Inhibition of Sporozoite Invasion Assay of Human Hepatoma Cells and Hepatocytes

摘要

Sera from human volunteers immunized with either synthetic peptide (NANP)3-TT orrecombinant protein R32tet32 Plasmodium falciparum CS vaccines were tested in the inhibition of sporozoite invasion (ISI) assays using human hepatoma (HepG2-A16) cells or primary human hepatocytes. Sera or purified immunoglobulin (Ig) from volunteers who were completely protected against P. falciparum sporozoite challenge had higher ISI activity than sera from non-protected volunteers, or the highest tire endemic serum. Malaria is transmitted by the bite of infected Anopheles mosquitoes which inject Plasmodium sporozoites into the mammalian host, where they invade hepatocytes and develop into exoerythrocytic (EE) parasites. After repeated exposures to bites of infected mosquitoes, humans develop antibodies to sporozoites which recognize mainly the immunodominant repeat region of the circumsporozoite (CS) protein.