Active and Passive Immunization against Plasmodium Yoelii Sporozoites
NAVAL MEDICAL RESEARCH INST BETHESDA MD
Pagination or Media Count:
Three subunit vaccines based on the major repeat, OGPGAPn, and flanking regions of the Plasmodium yoelii circumsporozoite protein were designed, produced, and tested. All were immunogenic, but none gave consistent protection against a 40-200 sporozoite challenge. To demonstrate that antibodies to P. yoelii CS protein could provide protection we established a passive transfer model. Passive transfer of NYS1, an lgG3 MAb against the P. yeolii CS protein, protected 100 of mice against challenge with 5000 P.yoelii sporozoites. Binding of NYS1 to sporozoites was inhibited by incubation with QGPGAP2, indicating that the epitope on sporozoites recognized by this MAb was included within this peptide. The levels of antibodies to QGPGAP2 by ELISA, and to sporozoites by IFAT and CS precipitation reaction were similar in sera from mice that received NYS1 in passive transfer and were protected against challenge with 5000 sporozoites, and from mice that had been immunized with subunit vaccines containing QGPGAP but were not protected against challenge with 40-200 sporozoites.
- Medicine and Medical Research