Trypanosoma cruzi reprograms mitochondrial metabolism within the anterior midgut of its vector Rhodnius prolixus during the early stages of infection

Abstract

Background: Trypanosoma cruzi is transmitted to humans by hematophagous bugs belonging to the Triatominae subfamily. Its intra-vectorial cycle is complex and occurs exclusively in the insect's midgut. Dissecting the elements involved in the cross-talk between the parasite and its vector within the digestive tract should provide novel targets for interrupting the parasitic life cycle and affecting vectorial competence. These interactions are shaped by the strategies that parasites use to infect and exploit their hosts, and the host's responses that are designed to detect and eliminate parasites. The objective of the current study is to characterize the impact of T. cruzi establishment within its vector on the dynamics of its midgut.

Methods: In this study, we evaluated the impact of T. cruzi infection on protein expression within the anterior midgut of the model insect Rhodnius prolixus at 6 and 24 h post-infection (hpi) using high-throughput quantitative proteomics.

Results: Shortly after its ingestion, the parasite modulates the proteome of the digestive epithelium by upregulating 218 proteins and negatively affecting the expression of 11 proteins involved in a wide array of cellular functions, many of which are pivotal due to their instrumental roles in cellular metabolism and homeostasis. This swift response underscores the intricate manipulation of the vector's cellular machinery by the parasite. Moreover, a more in-depth analysis of proteins immediately induced by the parasite reveals a pronounced predominance of mitochondrial proteins, thereby altering the sub-proteomic landscape of this organelle. This includes various complexes of the respiratory chain involved in ATP generation. In addition to mitochondrial metabolic dysregulation, a significant number of detoxifying proteins, such as antioxidant enzymes and P450 cytochromes, were immediately induced by the parasite, highlighting a stress response.

Conclusions: This study is the first to illustrate the response of the digestive epithelium upon contact with T. cruzi, as well as the alteration of mitochondrial sub-proteome by the parasite. This manipulation of the vector's physiology is attributable to the cascade activation of a signaling pathway by the parasite. Understanding the elements of this response, as well as its triggers, could be the foundation for innovative strategies to control the transmission of American trypanosomiasis, such as the development of targeted interventions aimed at disrupting parasite proliferation and transmission within the triatomine vector.

Keywords: Chagas disease; Host–parasite interaction; Mitochondria; Quantitative proteomics.

Fig. 1

Volcano plot showing the differential protein expression between uninfected and T. cruzi-infected R. prolixus AM. Differential analysis of the AM proteome of uninfected and infected insects at 6 and 24 h post-feeding. y-axis: negative log10 of P-value; x-axis: log2-transformed fold change; red dots: upregulated proteins with significant P-value; blue dots: downregulated proteins with significant P-value; black dots under the significance lines: non-variable proteins. Differentially expressed proteins were determined by Student’s t-test (P ≤ 0.05) and FC ≥ 2

Fig. 2

Functional classification of T. cruzi-regulated proteins in the AM of R. prolixus at 6 and 24 hpi. The differentially expressed proteins were categorized based on their functional roles in specific biological processes. This classification relied on Gene Ontology (GO) annotations as well as the presence of functional domains within the protein sequences. The bar height for each biological process represents the level of the differential expression

Fig. 3

Mitochondrial physiological changes in R. prolixus AM in response to T. cruzi infection. A Subcellular location of DEPs at 6 h and 24 hpi by T. cruzi. B Bubble chart illustrating upregulated proteins 6 hpi associated with various mitochondrial functions. Proteins are clustered based on their respective mitochondrial functions, each represented by a distinct color. The bubble size is correlated to its FC following infection