Fig. 3.

α-AgAPN1 PAbs block P. berghei and P. falciparum development in mosquitoes. (a) α-AgAPN1 IgG and Fab fragments inhibit oocyst development in mosquitoes. A. gambiae mosquitoes were fed on P. berghei-infected mice that were passively immunized (i.v.) with α-AgAPN1 IgG or Fab. Numbers of mosquitoes analyzed are shown in the bottom of each column. Pooled data from three replicate experiments are shown. Asterisks denote significance values of P < 0.05 (*) and P < 0.0001 (**). (b) Salivary gland and midgut peptide 1 (SM1) and α-AgAPN1 IgG produces additive but incomplete transmission-blocking immunity. Note that these experiments could be performed only by using P. berghei because SM1 did not block significantly P. falciparum in our experiments (34% maximal inhibition, P > 0.05; results not shown). (c) α-AgAPN1 IgG inhibit P. falciparum development in A. gambiae (AnG) and A. stephensi (AnS). Mosquitoes were fed on P. falciparum-infected blood containing 200 μg/ml of α-AgAPN1 IgG. Control (CTRL) mosquitoes were fed on infected blood along with an equivalent concentration of preimmune rabbit IgG. Results represent pooled data from three independent experiments. (b and c) The horizontal bar and number indicate the median oocyst number per mosquito midgut for each IgG treatment group. The number of mosquitoes analyzed (N) and range in oocyst number are indicated in the table. Mosquito infection prevalence between control and treatment groups for all our transmission-blocking experiments did not differ significantly (ranging between 80% and 95% prevalence). Percentage inhibition = [(control median oocyst no. − experimental median oocyst no.)/control median oocyst no.)] × 100.