Hemolytic C-Type Lectin CEL-III from Sea Cucumber Expressed in Transgenic Mosquitoes Impairs Malaria Parasite Development

Abstract

The midgut environment of anopheline mosquitoes plays an important role in the development of the malaria parasite. Using genetic manipulation of anopheline mosquitoes to change the environment in the mosquito midgut may inhibit development of the malaria parasite, thus blocking malaria transmission. Here we generate transgenic Anopheles stephensi mosquitoes that express the C-type lectin CEL-III from the sea cucumber, Cucumaria echinata, in a midgut-specific manner. CEL-III has strong and rapid hemolytic activity toward human and rat erythrocytes in the presence of serum. Importantly, CEL-III binds to ookinetes, leading to strong inhibition of ookinete formation in vitro with an IC50 of 15 nM. Thus, CEL-III exhibits not only hemolytic activity but also cytotoxicity toward ookinetes. In these transgenic mosquitoes, sporogonic development of Plasmodium berghei is severely impaired. Moderate, but significant inhibition was found against Plasmodium falciparum. To our knowledge, this is the first demonstration of stably engineered anophelines that affect the Plasmodium transmission dynamics of human malaria. Although our laboratory-based research does not have immediate applications to block natural malaria transmission, these findings have significant implications for the generation of refractory mosquitoes to all species of human Plasmodium and elucidation of mosquito–parasite interactions.

Hemagglutinating/Hemolytic activities in extracts of marine invertebrates from the Brazilian coast and isolation of two lectins from the marine sponge Cliona varians and the sea cucumber Holothuria grisea

“…Many of these compounds, which have already been isolated and studied, belong to marine invertebrates, such as sponges, cnidarians, mollusks, arthropods, echinoderms and tunicates (Rasjasa et al 2011). Among these compounds are proteins (Pajic et al 2002, Yoshida et al 2007) and secondary metabolites (Kuramoto et al 2004, Sipkema et al 2005) with a wide range of biological activities.…”

“…For instance, a lectin isolated from the sea cucumber Cucumaria echinata (CEL-III) was expressed in transgenic mosquitoes and impairs the development of the Malaria parasite (Yoshida et al 2007). Lectins isolated from the marine sponges Haliclona cratera and Craniella australiensis displayed cytotoxic effect against malignant cells and mitogenic response towards BALB/c splenocytes, respectively (Pajic et al 2002, Xiong et al 2006.…”

Hemozoin as an immune stimulant of the mosquitoAnopheles gambiaeresponse against the malaria parasite

“…stephensi Moreira et al, 2002;Yoshida et al, 2007;Dong et al, 2011;Introduction In the case of Anopheles transgenic manipulation, this could result in the overproduction of an anti-Plasmodium factor or silencing of a Plasmodium positive regulator, culminating in a decline in the overall number of parasites, therefore interfering with Plasmodium cycle through reduction of transmission to the vertebrate host.…”

Transgenesis, Paratransgenesis and Transmission Blocking Vaccines to Prevent Insect-Borne Diseases

“…When expressed in An. stephensi, CELIII is was shown to be cytotoxic to P. berghei ookinetes, reducing prevalence and intensity by 84% and 90%, respectively (Yoshida et al 2007). CELIII expression was driven by a midgut-specific An.…”

“…funestus) has been successfully transformed and displayed reduced vector competence. Moreover, only one strain of transgenic mosquitoes blocked the development of P. falciparum, the principal human malaria parasite (Yoshida et al 2007). The only exceptions of transgenic insect lines robustly impairing development of a human pathogen in its human vector are the transgenic strain of Ae.…”