Differential Expression Profiles in the Midgut of Triatoma infestans Infected with Trypanosoma cruzi

Abstract

Chagas disease, or American trypanosomiasis, is a parasitic disease caused by the protozoan Trypanosoma cruzi and is transmitted by insects from the Triatominae subfamily. To identify components involved in the protozoan-vector relationship, we constructed and analyzed cDNA libraries from RNA isolated from the midguts of uninfected and T. cruzi-infected Triatoma infestans, which are major vectors of Chagas disease. We generated approximately 440 high-quality Expressed Sequence Tags (ESTs) from each T. infestans midgut cDNA library. The sequences were grouped in 380 clusters, representing an average length of 664.78 base pairs (bp). Many clusters were not classified functionally, representing unknown transcripts. Several transcripts involved in different processes (e.g., detoxification) showed differential expression in response to T. cruzi infection. Lysozyme, cathepsin D, a nitrophorin-like protein and a putative 14 kDa protein were significantly upregulated upon infection, whereas thioredoxin reductase was downregulated. In addition, we identified several transcripts related to metabolic processes or immunity with unchanged expressions, including infestin, lipocalins and defensins. We also detected ESTs encoding juvenile hormone binding protein (JHBP), which seems to be involved in insect development and could be a target in control strategies for the vector. This work demonstrates differential gene expression upon T. cruzi infection in the midgut of T. infestans. These data expand the current knowledge regarding vector-parasite interactions for Chagas disease.

Parasite Cathepsin D-Like Peptidases and Their Relevance as Therapeutic Targets

“…APD activity levels increase in the posterior midgut of R. prolixus upon T. cruzi colonization [50]. This finding is also supported by differential APD expression in the midgut of infected/uninfected T. infestans [51]. In all ectoparasite vectors, studies on the interaction of intestinal digestive proteases with symbionts or transmitted pathogens will be necessary to understand how microorganisms establish in this harsh environment, and future work to elucidate this interplay will be essential.…”

Protein 2DE reference map of the anterior midgut of the blood‐sucking bug Rhodnius prolixus

“…Interestingly, their observed masses are below the expected ones suggesting the presence of the processed form. Although the function of these enzymes in the AM is not clear, it has been observed that cathepsin D gene expression increases during T. cruzi infection suggesting its potential implication in parasite–host interaction.…”

“…The spot position (below 15 kDa) suggests that the protein has lost its signal peptide and is thus active. The enzyme has been related to trypanosome infection as its expression level increases in the AM upon Triatoma infestans infection . It has as well been related to the digestion of R. prolixus symbiont Rhodococcus rhodnii .…”

Peer Review #2 of "Differential transcript profile of inhibitors with potential anti-venom role in the liver of juvenile and adult Bothrops jararaca snake (v0.1)"

“…Reactions were submitted to 36 cycles of 96ºC -10 sec, 50ºC -10 sec and 60ºC -4 min, followed by precipitation with ethanol and sodium acetate buffer. DNA sequencing was carried on an ABI 3130 sequencer (Applied Biosystems) as described by Buarque et al (2013).…”