Extracellular vesicles isolated from Trypanosoma cruzi affect early parasite migration in the gut of Rhodnius prolixus but not in Triatoma infestans.

Larissa F Paranaiba,Maria N Melo,Alessandra A Guarneri,Rodrigo P Soares,Ana C Torrecilhas

doi:10.1590/0074-02760190217

Abstract

The protozoan Trypanosoma cruzi has the ability to spontaneously secrete extracellular vesicles (EVs). In this paper, T. cruzi EVs derived from epimastigote forms were evaluated during interaction with triatomine bugs Rhodnius prolixus and Triatoma infestans. T. cruzi EVs were purified and artificially offered to the insects prior to infection with epimastigote forms. No effect of EVs was detected in the parasite counts in the guts of both vectors after 49-50 days. On the other hand, pre-feeding with EVs delayed parasite migration to rectum only in the gut in R. prolixus after 21-22 days. Those data suggest a possible role of T. cruzi EVs during the earlier events of infection in the invertebrate host.

Highlights

Chagas disease is caused by the protozoan Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae)
T. cruzi is transmitted by triatomines (Reduviidae: Triatominae) including Triatoma infestans and Rhodnius prolixus, the most important vectors in Latin America.[1,2,3]
Bug2149 cl10 T. cruzi strain (Bug), originally isolated from naturally infected T. infestans (Rio Grande do Sul, Brazil) was used.[13]. Epimastigote forms were cultured in liver-infusion tryptose (LIT) supplemented with 15% foetal bovine serum (FBS), 100 μg/mL streptomycin, 100 units/mL penicillin (27oC and pH 7.2)

Summary

Introduction

Chagas disease is caused by the protozoan Trypanosoma cruzi (Kinetoplastida: Trypanosomatidae). We provide evidence that in the digestive tract of triatomine vetors, T. cruzi EVs were able to functionally affect early parasite migration in R. prolixus and had no effect on the number of metacyclics in both vector species. The midgut and rectum of a group of nymphs (n = 20) were individually dissected (Fig. 1) and homogenised in 30 μL of PBS (0.15 M NaCl at 0.01 M sodium phosphate, pH 7.4) at 21-22 days post infection (p.i.).

Results

Conclusion