Two antigens on zygotes and ookinetes of Plasmodium yoelii and Plasmodium berghei that are distinct targets of transmission-blocking immunity.
We have developed transmission-blocking monoclonal antibodies (MAbs) against Plasmodium yoelii 21-kDa (Pys21) and 28-kDa (Pys25) ookinete surface proteins. These MAbs block infectivity of P. yoelii to Anopheles stephensi. One MAb, 14, cross-reacted by Western blotting with a 28-kDa surface protein (Pbs25) of P. berghei ookinetes and blocked oocyst development, as assayed by direct mosquito feeds on passively immunized P. berghei-infected mice. In total, we have identified two ookinete surface proteins in P. yoelii, one of which is also present in P. berghei. The transmission-blocking activity of the anti-Pys25 MAb 4 was complete and more potent than that of the anti-Pys21 MAb 2. Moreover, Fab fragments of MAb 4 had transmission-blocking activity in mice. In comparison, Fab fragments of MAb 2 did not have detectable transmission-blocking effect, although F(ab')2 did. Furthermore, MAb 2 and MAb 4 appeared to block the in vitro formation and development of zygotes as well.
Tsuboi
T
T
Department of Parasitology, Ehime University School of Medicine, Shigenobu-cho, Japan.
Cao
Y M
YM
Hitsumoto
Y
Y
Yanagi
T
T
Kanbara
H
H
Torii
M
M
D000818:Animals; D000852:Anopheles / Q000469:parasitology*; D000911:Antibodies, Monoclonal / Q000276:immunology; D000953:Antigens, Protozoan / Q000276:immunology*; D005260:Female; D007114:Immunization; D007140:Immunoglobulin Fab Fragments / Q000276:immunology; D007303:Insect Vectors / Q000469:parasitology*; D051379:Mice; D008811:Mice, Inbred DBA; D008813:Mice, Inbred ICR; D010962:Plasmodium berghei / Q000276:immunology*; D010967:Plasmodium yoelii / Q000276:immunology*; D015053:Zygote / Q000502:physiology
D000911:Antibodies, Monoclonal; D000953:Antigens, Protozoan; D007140:Immunoglobulin Fab Fragments