Interactions of human malaria parasites, Plasmodium wVaxand P.falciparum, with the midgut of Anopheles mosquitoes

Abstract

Present understanding of the development of sexual stages of the human malaria parasites Plasmodium vivax and P.falciparum in the Anopheles vector is reviewed, with particular reference to the role of the mosquito midgut in establishing an infection. The sexual stages of the parasite, the gametocytes, are formed in human erythrocytes. The changes in temperature and pH encountered by the gametocyte induce gametogenesis in the lumen of the midgut. Macromolecules derived from mosquito tissue and second messenger pathways regulate events leading to fertilization. In An.tessellatus the movement of the ookinete from the lumen to the midgut epithelium is linked to the release of trypsin in the midgut and the peritrophic matrix is not a firm barrier to this movement. The passage of the P.vivax ookinete through the peritrophic matrix may take place before the latter is fully formed. The late ookinete development in P.falciparum requires chitinase to facilitate penetration of the peritrophic matrix. Recognition sites for the ookinetes are present on the midgut epithelial cells. N-acetyl glucosamine residues in the oligosaccharide side chains of An.tessellatus midgut glycoproteins and peritrophic matrix proteoglycan may function as recognition sites for P.vivax and P.falciparum ookinetes. It is possible that ookinetes penetrating epithelial cells produce stress in the vector. Mosquito molecules may be involved in oocyst development in the basal lamina, and encapsulation of the parasite occurs in vectors that are refractory to the parasite. Detailed knowledge of vector-parasite interactions, particularly in the midgut and the identification of critical mosquito molecules offers prospects for manipulating the vector for the control of malaria.

The mosquitoAnopheles stephensilimits malaria parasite development with inducible synthesis of nitric oxide

“…In contrast, both P. berghei- (Fig. 4B) and P. falciparum-infected midguts (not shown) at 24 hr pBM also showed darkly stained individual cells concentrated in the posterior midgut, where Plasmodium development typically occurs (29). Doublestaining of midguts with diaphorase and propidium iodide demonstrated that, in some cases, diaphorase-positive cells were colocalized with immature oocysts of both species (data not shown).…”

Anti-mosquito midgut antibodies block development of Plasmodium falciparum and Plasmodium vivax in multiple species of Anopheles mosquitoes and reduce vector fecundity and survivorship

“…The finding of midgut-based TBI in both human and rodent malaria models is noteworthy because different Plasmodium species display different developmental kinetics in the mosquito (12)(13)(14)(15)(16).…”

Different prevalences of Plasmodium vivax phenotypes VK210 and VK247 associated with the distribution of Anopheles albimanus and Anopheles pseudopunctipennis in Mexico.

“…Because these were not observed, it is difficult to directly associate the CS protein phenotypes with the resistance process. Other possible unidentified molecular differences in early sporogonic stages of the parasite phenotypes may exist that, in interaction with each mosquito species' midgut structure 27 and physiology, [28][29][30] could determine mosquito species-specific parasite infectivity.…”