Ookinete antigens of Plasmodium berghei. Appearance on the zygote surface of an Mr 21 kD determinant identified by transmission‐blocking monoclonal antibodies

摘要: Zygotes and ookinetes of the rodent malaria Plasmodium berghei can be enriched 50-fold, from whole blood cultures by ammonium chloride lysis. Three monoclonal antibodies (MoAbs) raised against such preparations specifically bind to a determinant Mr 21 kD as assessed 125I-labelled goat anti-mouse IgG probed immunoblots Western transfers SDS-PAGE gels. Indirect immunofluorescence indicates that bound specific MoAbs, whilst not detectable on gametocytes or gametes, appears parasite surface within 2 h exflagellation/fertilization increases thereafter. The three MoAbs binding block oocyst development in mosquitoes at least 90%, either in-vitro membrane feeds live passively immunized mice. These reduce ookinete formation vitro between 52 100%. Possible mechanisms action these are discussed.