| cytokines kill malaria parasites during infection crisis: extracellular complementary factors are essential. | malaria infection crisis, at which the parasitemia drops precipitously and the parasite loses infectivity to the mosquito vector, occurs in many natural malaria systems, and has not been explained. we demonstrate that in a simian malaria parasite (plasmodium cynomolgi in its natural host, the toque monkey), the loss of infectivity during crisis is due to the death of circulating intraerythrocytic gametocytes mediated by crisis serum. these parasite-killing effects in crisis serum are due to the ... | 1991 | 1900073 |
| plasmodium cynomolgi: serum-mediated blocking and enhancement of infectivity to mosquitoes during infections in the natural host, macaca sinica. | the infectivity of plasmodium cynomolgi in its natural host, the toque monkey, macaca sinica, to anopheles tessellatus mosquitoes was studied in relation to the evolution of anti-sexual-stage immunity in the host during the course of a blood-induced infection. the effects of serum on the infectivity of gametocytes and the intrinsic infectivity of gametocytes to mosquitoes on each day were assessed in membrane feeding experiments. mosquitoes were also directly fed on the animal on each day. our r ... | 1990 | 2209788 |
| baculovirus merozoite surface protein 1 c-terminal recombinant antigens are highly protective in a natural primate model for human plasmodium vivax malaria. | a successful anti-blood stage malaria vaccine trial based on a leading vaccine candidate, the major merozoite surface antigen-1 (msp1), is reported here. the trial was based on plasmodium cynomolgi, which is a primate malaria parasite which is highly analogous to the human parasite plasmodium vivax, in its natural host, the toque monkey, macaca sinica. two recombinant baculovirus-expressed p. cynomolgi msp1 proteins, which are analogous to the 42- and 19-kda c-terminal fragments of p. falciparum ... | 1998 | 9529073 |
| strain-specific protective effect of the immunity induced by live malarial sporozoites under chloroquine cover. | the efficacy of a whole-sporozoite malaria vaccine would partly be determined by the strain-specificity of the protective responses against malarial sporozoites and liver-stage parasites. evidence from previous reports were inconsistent, where some studies have shown that the protective immunity induced by irradiated or live sporozoites in rodents or humans were cross-protective and in others strain-specific. in the present work, we have studied the strain-specificity of live sporozoite-induced ... | 2012 | 23029282 |
| evidence for strain-specific protective immunity against blood-stage parasites of plasmodium cynomolgi in toque monkey. | we have conducted experiments to test the induction of strain-specific protective immunity against plasmodium cynomolgi infections in toque monkeys. plasmodium cynomolgi is closely related biologically and genetically to the human malaria parasite, p. vivax. two groups of monkeys were immunized against either of two strains of p. cynomolgi, namely pcceylon and pc746, by giving two successive drug-cured infections with asexual blood-stage parasites of one or the other strain, 12-weeks apart. to t ... | 2008 | 19067844 |