INHIBITION OF THE INVITRO GROWTH OF PLASMODIUM-FALCIPARUM .1. EFFECTS OF IMMUNE SERUM AND PURIFIED IMMUNOGLOBULIN FROM OWL MONKEYS

Abstract

Sera from Aotus sp. monkeys (karyotypes II, III and IV) which were immune to P. falciparum were used to inhibit the in vitro growth of this human malaria parasite. Culture conditions used for the assays allowed 50- to 100-fold increases in the number of A+ erythrocytes infected in a 96 h period in control cultures. Although normal monkey serum did not support growth as well as normal human serum, mixtures of normal monkey and human serum were found that did. Compared to such controls, as little as 3.5% immune monkey serum caused approximately 56% inhibition in 4 days(2 replicative cycles). Purified globulin from immune monkeys inhibited 40% at 2 mg/ml and 75% at 7 mg/ml after a single replicative cycle. These data suggest that serum antibody is likely to play a major role in providing Aotus monkeys with protective immunity to P. falciparum.