Penetration of the salivary glands of Rhodnius domesticus Neiva & Pinto, 1923 (Hemiptera: Reduviidae) by Trypanosoma rangeli Tejera, 1920 (Protozoa: Kinetoplastida)

Abstract

Penetration of the heteroxenous protozoan Trypanosoma rangeli into the salivary glands of its invertebrate host Rhodnius domesticus has been investigated here using different approaches. Electron microscopy showed that epimastigotes coming from the insect hemocoel cross the basal lamina that surrounds the salivary glands and penetrate through the gland cells cytoplasm. After reaching the gland lumen, epimastigote forms remain adhered to the gland cell microvilli by their flagella, while metacyclic trypomastigotes are found swimming free in the saliva. Analysis by flow cytometry, western blotting and hemolytic activity allowed to demonstrate the presence in T. rangeli of a hemolytic molecule with antigenic cross-reactivity with murine perforin, which could be used by the parasites to reach the salivary gland lumen. This molecule, which we named as rangelysin, has 120 kDa molecular weight, is able to induce hemolysis only in acidic pH, and is produced by both trypomastigote and epimastigote forms.

Evidence That a Laminin-Like Insect Protein Mediates Early Events in the Interaction of a Phytoparasite with Its Vector's Salivary Gland

“…In the trypanosomatid-insect interactions, the adhesion to host tissue seems to occur mainly through the flagella [37]–[40], and binding through the cellular body is rarely observed [41], [42]. In contrast with a previous study that showed Trypanosoma rangeli invading Rhodnius prolixus salivary glands with the flagellum foremost [27], the passage of P. serpens parasites through the basal lamina of O. fasciatus salivary gland occurred through the cellular body. In addition, the invasion of several parasites in an area with altered morphology and the presence of suggestive lesions were observed.…”

“…The salivary glands of the infected insects were obtained by gently pulling off their heads [27]. Parasite adhesion to the outer surface of the salivary glands was observed by SEM.…”

“…Control insects were injected with 4 µl sterile PBS. The salivary glands of the insects were dissected and explanted at 2, 6, 24, 48 and 72 hours post-infection [27].…”

Trypanosoma rangeli protein tyrosine phosphatase is associated with the parasite's flagellum

“…The mechanisms involved in adhesion to a substrate in T. brucei (Ersfeld & Gull 2001) T. cruzi (Ferreira et al 2008) and T. rangeli (Meirelles et al 2005) require the crucial and active participation of the flagella of these parasites. During metacyclogenesis, the flagellar membrane remains connected to the epithelial surface (Ersfeld & Gull 2001) representing an important interface between the parasite and its host that is essential for the fulfilment of its biological cycle.…”

Primary culture of Rhodnius prolixus (Hemiptera: Reduviidae) salivary gland cells

“…The morphology of the cells is still not completely known. In Rhodnius domesticus, Meirelles et al (2003) showed that the main salivary glands have mononuclear cells, whereas Anhê et al (2007) described binucleated cells in both the main salivary gland and the accessory gland from R. prolixus and Rhodnius neglectus.…”