Proteome of the Triatomine Digestive Tract: From Catalytic to Immune Pathways; Focusing on Annexin Expression

Abstract

Rhodnius prolixus, Panstrongylus megistus, Triatoma infestans, and Dipetalogaster maxima are all triatomines and potential vectors of the protozoan Trypanosoma cruzi responsible for human Chagas’ disease. Considering that the T. cruzi’s cycle occurs inside the triatomine digestive tract (TDT), the analysis of the TDT protein profile is an essential step to understand TDT physiology during T. cruzi infection. To characterize the protein profile of TDT of D. maxima, P. megistus, R. prolixus, and T. infestans, a shotgun liquid chromatography-tandem mass spectrometry (LC-MS/MS) approach was applied in this report. Most proteins were found to be closely related to metabolic pathways such as gluconeogenesis/glycolysis, citrate cycle, fatty acid metabolism, oxidative phosphorylation, but also to the immune system. We annotated this new proteome contribution gathering it with those previously published in accordance with Gene Ontology and KEGG. Enzymes were classified in terms of class, acceptor, and function, while the proteins from the immune system were annotated by reference to the pathways of humoral response, cell cycle regulation, Toll, IMD, JNK, Jak-STAT, and MAPK, as available from the Insect Innate Immunity Database (IIID). These pathways were further subclassified in recognition, signaling, response, coagulation, melanization and none. Finally, phylogenetic affinities and gene expression of annexins were investigated for understanding their role in the protection and homeostasis of intestinal epithelial cells against the inflammation.

Early Post-Prandial Regulation of Protein Expression in the Midgut of Chagas Disease Vector Rhodnius prolixus Highlights New Potential Targets for Vector Control Strategy

“…It is noteworthy to mention that although proteins associated with IMD, Toll, and Jak/STAT pathways involved in innate immunity have been identified in R. prolixus digestive tract proteomes [ 20 , 95 , 96 ], the early events post blood feeding resume in the induction of these very few immune-related proteins. Although lysozymes have been suggested to have a role in immunity, the observed up-regulation in the early hours post blood ingestion supports their digestive function.…”

The Fate of Dietary Cholesterol in the Kissing Bug Rhodnius prolixus

“…This enzyme catalyzes the synthesis of esterified cholesterol and lysophosphatidylcholine from cholesterol and phosphatidylcholine ( Ossoli et al, 2016 ), and it is present in the rabbit blood used for insect feeding ( Carlucci et al, 2012 ). A recent proteomic analysis of R. prolixus midgut showed that enzymes involved with lipid utilization are highly expressed in this organ, confirming that it is very active in terms of lipid metabolism ( Gumiel et al, 2020 ). Thus, an alternative explanation may be the excretion of esterified cholesterol synthesized by the intestinal cells.…”

Near infrared spectroscopy accurately detects Trypanosoma cruzi non-destructively in midguts, rectum and excreta samples of Triatoma infestans

“…For instance, the relative abundance of gut bacterial community in T. sordida varied greatly among the anterior and posterior midgut, and hindgut 43 . The protein profile expression of T. infestans digestive tract seems to be affected by the ingestion of blood meal 44 . The varying chemical profile is expected to be reflected in the spectral signature and could overlap with the presence of the pathogen.…”