Trypanosoma rangeli infection increases the exposure and predation endured by Rhodnius prolixus.

Trypanosoma rangeli is a protozoan that infects triatomines and mammals in Latin America, sharing hosts with Trypanosoma cruzi, the etiological agent of Chagas disease. Trypanosoma rangeli does not cause disease to humans but is strongly pathogenic to its invertebrate hosts, increasing mortality rates and affecting bug development and reproductive success. We have previously shown that this parasite is also capable of inducing a general increase in the locomotory activity of its vector Rhodnius prolixus in the absence of host cues. In this work, we have evaluated whether infection impacts the insect­vertebrate host interaction. For this, T. rangeli-infected and uninfected R. prolixus nymphs were released in glass arenas offering single shelters. After a 3-day acclimatization, a caged mouse was introduced in each arena and shelter use and predation rates were evaluated. Trypanosoma rangeli infection affected all parameters analysed. A larger number of infected bugs was found outside shelters, both in the absence and presence of a host. Infected bugs also endured greater predation rates, probably because of an increased number of individuals that attempted to feed. Interestingly, mice that predated on infected bugs did not develop T. rangeli infection, suggesting that the oral route is not effective for these parasites, at least in our system. Finally, a smaller number of infected bugs succeeded in feeding in this context. We suggest that, although T. rangeli is not transmitted orally, an increase in the proportion of foraging individuals would promote greater parasite transmission rates through an increased frequency of very effective infected-bug bites.

Trypanosoma rangeli infection impairs reproductive success of Rhodnius prolixus.

Trypanosoma rangeli is a protozoan that infects triatomines and mammals in Central and South America. Although it does not cause disease to humans, this parasite produces different levels of pathogenicity to its invertebrate host, mainly in species of the genus Rhodnius. In this study, we followed T. rangeli-infected and uninfected pairs throughout their adult lives and measured the amount of blood ingested, number of eggs laid, number of eggs hatched and proportion of infertile eggs, as well as female life expectancy. We found that all reproductive parameters were drastically decreased during infection, mainly due to the reduced amount of blood the infected insects ingested throughout their lives. Reproductive parameters were also affected by the reduction of the life expectancy of infected females, as survival was positively correlated with the number of eggs laid. The strategies used by the parasite to be transmitted are discussed in view of the pathological effects it causes in the insect.

Differential expression and activity of arginine kinase between the American trypanosomatids Trypanosoma rangeli and Trypanosoma cruzi.

Trypanosoma rangeli is a non-virulent hemoflagellate parasite infecting humans, wild and domestic mammals in Central and Latin America. The share of genotypic, phenotypic, and biological similarities with the virulent, human-infective T. cruzi and T. brucei, allows comparative studies on mechanisms of pathogenesis. In this study, investigation of the T. rangeli Arginine Kinase (TrAK) revealed two highly similar copies of the AK gene in this taxon, and a distinct expression profile and activity between replicative and infective forms. Although TrAK expression seems stable during epimastigotes growth, the enzymatic activity increases during the exponential growth phase and decreases from the stationary phase onwards. No differences were observed in activity or expression levels of TrAK during in vitro differentiation from epimastigotes to infective forms, and no detectable AK expression was observed for blood trypomastigotes. Overexpression of TrAK by T. rangeli showed no effects on the in vitro growth pattern, differentiation to infective forms, or infectivity to mice and triatomines. Although differences in TrAK expression and activity were observed among T. rangeli strains from distinct genetic lineages, our results indicate an up-regulation during parasite replication and putative post-translational myristoylation of this enzyme. We conclude that up-regulation of TrAK activity in epimastigotes appears to improve proliferation fitness, while reduced TrAK expression in blood trypomastigotes may be related to short-term and subpatent parasitemia in mammalian hosts.

High sensitivity and reproducibility of in-house ELISAs using different genotypes of Trypanosoma cruzi.

The adequate choice of Trypanosoma cruzi strains as antigen source for the diagnosis of Chagas disease is still controversial due to differences in terms of accuracy reported between different diagnostic tests. In this study was determined if the genetic variability between different genotypes of T. cruzi (TcI, TcII and TcIV) affect the final diagnosis of Chagas disease. The sensitivity and specificity index of in-house ELISA tests prepared with different T. cruzi strains were evaluated with chagasic and non-chagasic control sera and using the TESA-blot as a reference test. The results of this study revealed that the sensitivity index did not vary, with percentages of 100% for all strains in both tests. However, the specificity index for ELISA tests showed differences between 92% and 98%, but were reduced to 78%-89% when Leishmania-positive sera were included. All ELISAs and TESA-blot prepared with different antigens and the recombinant Wiener test were challenged in an endemic community for Chagas disease in Panama. Both ELISAs and TESA-blot recognized the same positive sera, corroborating the sensitivity indexes (100%) found with the control sera. The TESA-blot maintained the specificity index of 100% and did not display false positives. However, the recombinant Wiener test decreased its sensitivity to 81.25%.

Messenger RNA levels of the Polo-like kinase gene (PLK) correlate with cytokinesis in the Trypanosoma rangeli cell cycle.

BACKGROUND: Trypanosoma rangeli is a protozoan parasite that is non-virulent to the mammalian host and is morphologically and genomically related to Trypanosoma cruzi, whose proliferation within the mammalian host is controversially discussed. OBJECTIVES: We aimed to investigate the T. rangeli cell cycle in vitro and in vivo by characterizing the timespan of the parasite life cycle and by proposing a molecular marker to assess cytokinesis. METHODOLOGY: The morphological events and their timing during the cell cycle of T. rangeli epimastigotes were assessed using DNA staining, flagellum labelling and bromodeoxyuridine incorporation. Messenger RNA levels of four genes previously associated with the cell cycle of trypanosomatids (AUK1, PLK, MOB1 and TRACK) were evaluated in the different T. rangeli forms. FINDINGS: T. rangeli epimastigotes completed the cell cycle in vitro in 20.8 h. PLK emerged as a potential molecular marker for cell division, as its mRNA levels were significantly increased in exponentially growing epimastigotes compared with growth-arrested parasites or in vitro-differentiated trypomastigotes. PLK expression in T. rangeli can be detected near the flagellum protrusion site, reinforcing its role in the cell cycle. Interestingly, T. rangeli bloodstream trypomastigotes exhibited very low mRNA levels of PLK and were almost entirely composed of parasites in G1 phase. MAIN CONCLUSIONS: Our work is the first to describe the T. rangeli cell cycle in vitro and proposes that PLK mRNA levels could be a useful tool to investigate the T. rangeli ability to proliferate within the mammalian host bloodstream.

Using FT-IR spectroscopy for the identification of the T. cruzi, T. rangeli, and the L. chagasi species.

The cross-reaction in the diagnosis results is a serious problem, leading to an incorrect treatment and several injuries to patients. The Trypanosoma rangeli and Trypanosoma cruzi belong to the genus Trypanosoma, but the Trypanosoma rangeli is a non-pathogenic parasite to humans. While Trypanosoma cruzi is the etiological agent of Chagas' disease, which affects circa 2-3 million people and more than 6000 deaths annually in Brazil. The Leishmania chagasi causes infectious disease known as visceral leishmaniasis. This diseases have in common the crossed antigenic reaction promoted by serological tests and its differentiation is relevant for epidemiological studies and clinical practice. In this study the Fourier Transform Infrared (FT-IR) Spectroscopy was used to differentiate these microorganisms, which were cultivated and the spectra analyzed. Data analysis were performed by Gaussian curve fitting and multivariate statistical analysis. The cluster analysis have shown four specific regions to identify the microorganisms. The first three PCs of principal component analysis associated to linear discriminant were able to classify 95.6% of the parasites using cross-validation. The curve fitting method showed the quantitative differentiation among L. chagasi, T. cruzi, and T. rangeli species in the vibrational regions of polysaccharides, amide III, lipid esters, and fatty acid.

Molecular and biochemical characterization of natural and recombinant phosphoglycerate kinase B from Trypanosoma rangeli.

T. rangeli epimastigotes contain only a single detectable phosphoglycerate kinase (PGK) enzyme in their cytosol. Analysis of this parasite's recently sequenced genome showed a gene predicted to code for a PGK with the same molecular mass as the natural enzyme, and with a cytosolic localization as well. In this work, we have partially purified the natural PGK from T. rangeli epimastigotes. Furthermore, we cloned the predicted PGK gene and expressed it as a recombinant active enzyme. Both purified enzymes were kinetically characterized and displayed similar substrate affinities, with KmATP values of 0.13 mM and 0.5 mM, and Km3PGA values of 0.28 mM and 0.71 mM, for the natural and recombinant enzyme, respectively. The optimal pH for activity of both enzymes was in the range of 8-10. Like other PGKs, TrPGK is monomeric with a molecular mass of approximately 44 kDa. The enzyme's kinetic characteristics are comparable with those of cytosolic PGK isoforms from related trypanosomatid species, indicating that, most likely, this enzyme is equivalent with the PGKB that is responsible for generating ATP in the cytosol of other trypanosomatids. This is the first report of a glycolytic enzyme characterization from T. rangeli.

Effect of temperature and vector nutrition on the development and multiplication of Trypanosoma rangeli in Rhodnius prolixus.

Trypanosoma rangeli is a protozoan parasite that infects mammals and triatomines, causing different levels of pathogenicity in its invertebrate vectors, particularly those from the genus Rhodnius. We have recently shown that temperature can modulate T. rangeli growth during in vitro culture, as well as its in vivo pathogenicity to R. prolixus. In the present study, we investigated colonization of R. prolixus by T. rangeli and assessed the role of temperature and vector nutrition on parasite development and multiplication. We infected nymphs and either assessed parasite density in the first hours after the ingestion of the infected blood or maintained the nymphs for up to 60 days at different temperatures (21, 24, 27, and 30 °C) and under different blood-feeding schedules (either every 15 days, or on day 30 post infection only), with parasite development and multiplication measured on days 15, 30, and 60 post infection. In the first hours after ingesting infected blood, epimastigogenesis not only occurred in the anterior midgut, but a stable parasite population also established in this intestinal region. T. rangeli subsequently colonized all intestinal regions examined, but with fewer parasites being found in the rectum. The number of parasites was only affected by higher temperatures (27 and 30 °C) during the beginning of the infection (15 days post infection). Nutritional status of the vector also had a significant effect on parasite development, as reduced blood-feeding decreased infection rates by approximately 30%.

Limit of detection of PCR/RFLP analysis of cytochrome oxidase II for the identification of genetic groups of Trypanosoma cruzi and Trypanosoma rangeli in biological material from vertebrate hosts.

Mixed infections with Trypanosoma cruzi and Trypanosoma rangeli and their different genetic groups occur frequently in vertebrate hosts and are difficult to detect by serology. In the present study, we evaluated the limit of detection of polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP) analysis of cytochrome oxidase II (COII) for the identification of genetic groups of these two parasites in blood and tissue from vertebrate hosts. Reconstitution experiments were performed using human blood (TcI/TcII and KP1+/KP1-) and mouse tissue (TcI/TcII). We tested blood from patients who were in the chronic phase of Chagas disease and tissue from animals that were experimentally infected with all possible combinations of six discrete typing units. In blood samples, T. cruzi and T. rangeli were detected when 5 parasites (pa) were present in the sample, and genetic groups were identified when at least 50 pa were present in the sample. T. cruzi alone could be detected with 1 pa and genotyped (TcI/TcII) with 2 pa. T. rangeli was detected with 2 pa and genotyped (KP+/KP1-) with 25 pa. The present method more readily detected TcII and KP1- in both admixtures and alone. In mouse tissue, TcI and TcII were detected with at least 25 pa. The analysis of blood samples from patients and tissue from animals that were experimentally infected revealed low parasite loads in these hosts, which were below the limit of detection of the present method and could not be genotyped. Our findings indicate that the performance of PCR/RFLP analysis of COII is directly related to the amount and proportion of parasites that are present in the sample and the genetic groups to which the parasites belong.

Temperature and parasite life-history are important modulators of the outcome of Trypanosoma rangeli-Rhodnius prolixus interactions.

Trypanosoma rangeli is a protozoan parasite, which does not cause disease in humans, although it can produce different levels of pathogenicity to triatomines, their invertebrate hosts. We tested whether infection imposed a temperature-dependent cost on triatomine fitness using T. rangeli with different life histories. Parasites cultured only in liver infusion tryptose medium (cultured) and parasites exposed to cyclical passages through mice and triatomines (passaged) were used. We held infected insects at four temperatures between 21 and 30 °C and measured T. rangeli growth in vitro at the same temperatures in parallel. Overall, T. rangeli infection induced negative effects on insect fitness. In the case of cultured infection, parasite effects were temperature-dependent. Intermoult period, mortality rates and ecdysis success were affected in those insects exposed to lower temperatures (21 and 24 °C). For passaged-infected insects, the effects were independent of temperature, intermoult period being prolonged in all infected groups. Trypanosoma rangeli seem to be less tolerant to higher temperatures since cultured-infected insects showed a reduction in the infection rates and passaged-infected insects decreased the salivary gland infection rates in those insects submitted to 30 °C. In vitro growth of T. rangeli was consistent with these results.

Trypanosoma cruzi-Trypanosoma rangeli co-infection ameliorates negative effects of single trypanosome infections in experimentally infected Rhodnius prolixus.

Trypanosoma cruzi, causative agent of Chagas disease, co-infects its triatomine vector with its sister species Trypanosoma rangeli, which shares 60% of its antigens with T. cruzi. Additionally, T. rangeli has been observed to be pathogenic in some of its vector species. Although T. cruzi-T. rangeli co-infections are common, their effect on the vector has rarely been investigated. Therefore, we measured the fitness (survival and reproduction) of triatomine species Rhodnius prolixus infected with just T. cruzi, just T. rangeli, or both T. cruzi and T. rangeli. We found that survival (as estimated by survival probability and hazard ratios) was significantly different between treatments, with the T. cruzi treatment group having lower survival than the co-infected treatment. Reproduction and total fitness estimates in the T. cruzi and T. rangeli treatments were significantly lower than in the co-infected and control groups. The T. cruzi and T. rangeli treatment group fitness estimates were not significantly different from each other. Additionally, co-infected insects appeared to tolerate higher doses of parasites than insects with single-species infections. Our results suggest that T. cruzi-T. rangeli co-infection could ameliorate negative effects of single infections of either parasite on R. prolixus and potentially help it to tolerate higher parasite doses.

Inorganic phosphate uptake in unicellular eukaryotes.

BACKGROUND: Inorganic phosphate (Pi) is an essential nutrient for all organisms. The route of Pi utilization begins with Pi transport across the plasma membrane. SCOPE OF REVIEW: Here, we analyzed the gene sequences and compared the biochemical profiles, including kinetic and modulator parameters, of Pi transporters in unicellular eukaryotes. The objective of this review is to evaluate the recent findings regarding Pi uptake mechanisms in microorganisms, such as the fungi Neurospora crassa and Saccharomyces cerevisiae and the parasite protozoans Trypanosoma cruzi, Trypanosoma rangeli, Leishmania infantum and Plasmodium falciparum. MAJOR CONCLUSION: Pi uptake is the key step of Pi homeostasis and in the subsequent signaling event in eukaryotic microorganisms. GENERAL SIGNIFICANCE: Biochemical and structural studies are important for clarifying mechanisms of Pi homeostasis, as well as Pi sensor and downstream pathways, and raise possibilities for future studies in this field.

Differentiation between Trypanosoma cruzi and Trypanosoma rangeli using heat-shock protein 70 polymorphisms.

OBJECTIVE: Differential diagnosis of infection with Trypanosoma cruzi or T. rangeli is relevant for epidemiological studies and clinical practice as both species infect humans, but only T. cruzi causes Chagas' disease. Their common antigen determinants complicate the distinction between both species, while current PCR assays used for differentiation show some drawbacks. We developed and validated a generic PCR discriminating the species by restriction fragment length polymorphism (RFLP) analysis and a duplex PCR specifically amplifying a differently sized fragment of both species. METHODS: The assays are based upon a partial region of the heat-shock protein 70 gene (hsp70). The analytical sensitivity and specificity were determined for both PCRs. The assays were analytically evaluated on a panel of six T. cruzi, one T. cruzi marinkellei and four T. rangeli strains, various other infectious pathogens, a panel of spiked samples of T. cruzi, and artificially mixed infections of T. cruzi and T. rangeli. Finally, the tools were applied on 36 additional isolates of Trypanosoma species. RESULTS: The detection limit of the PCRs was between 0.05 and 0.5 parasite genomes, and 1-10 parasites spiked in 200 µl blood. In artificial mixtures, PCR-RFLP picked up both species in ratios up to 10(2) and duplex PCR up to 10(4) . In the 36 isolates tested, both single and mixed infections were identified. All assays were shown to be specific. CONCLUSION: Our PCRs show high potential for the differential diagnosis of T. cruzi and T. rangeli, which in view of their sensitivity can aid in the confirmation of infection with these parasites in vectors, reservoirs and clinical samples.

Can we heal Chagas infection?

We present a model for the parasite-antibody dynamical competition between Trypanosoma rangeli and its antibodies during the acute phase of an infection in a mammal host. The model reproduces experimental data from murine models found in the literature and allows us to demonstrate that a preinfection with T. rangeli induces a temporary protective effect against Chagas disease. As the mammal immune system is able to eliminate a single T. rangeli infection, the host high antibody levels, needed to resist the Chagas infection, are reduced with time, returning the system to the initial healthy state. Our results suggest that a preinfection with T. rangeli could be used to reduce the in-house vectorial parasitemia through repeated vaccination of domestic animals.

Rhodnius prolixus: modulation of antioxidant defenses by Trypanosoma rangeli.

Trypanosoma rangeli is a protozoan parasite of insects and mammals that is challenged by the constant action of reactive oxygen species, generated either by its own metabolism or through the host immune response. The aim of this work was to investigate whether T. rangeli is able to modify the redox state of its insect vector, Rhodnius prolixus, through the modulation of such antioxidant enzymes as superoxide dismutase (SOD), catalase, and GPx present in the midgut of the insect. We verified that in R. prolixus fed with blood infected with T. rangeli there is an increase in SOD activity in the anterior and posterior midguts. However, the activities of enzymes related to hydrogen peroxide and hydroperoxides metabolism, such as catalase and GPx, were decreased in relation to the insect control group, which was only fed blood. These changes in the redox state of the vector led to an increase in lipid peroxidation and thiol oxidation levels in the anterior and posterior midgut tissues. We also verified that the addition of 1 mM GSH in the blood meal of the infected insects increased the proliferation of these parasites by 50%. These results suggest that there is an increase in oxidative stress in the insect gut during T. rangeli infection, and this condition could contribute to the control of the proliferation of these parasites.

Immune signaling pathways in Rhodnius prolixus in the context of Trypanosoma rangeli infection: cellular and humoral immune responses and microbiota modulation.

Introduction: Rhodnius prolixus is a hematophagous insect and one of the main vectors for Trypanosoma cruzi and Trypanosoma rangeli parasites in Latin America. Gut microbiota and insect immune responses affect T. cruzi and T. rangeli infection within triatomines. Particularly the Toll and IMD signaling pathways activations and how they orchestrate the antimicrobial peptides (AMPs) expressions in R. prolixus, especially when infected by T. rangeli. Objectives: Examine how T. rangeli infection modulates R. prolixus cellular and humoral immunity and its impacts on insect microbiota. Methods: R. prolixus was fed on blood containing epimastigotes of T. rangeli, and infection was quantified in insect tissues. The gene expression of dorsal, cactus, relish, PGRP, and AMPs was examined in the midgut, fat body, and salivary glands by quantitative real-time PCR. Microbiota composition was analyzed using RT-q PCR targeting specific bacterial species. Hemocyte numbers and phenoloxidase activity were quantified to assess cellular immune responses. Results: T. rangeli infection modulated triatomine immunity in midgut and hemocoel, activating the expression of the NF-kB gene dorsal, associated with the Toll pathway; increasing expression of the gene encoding PGRP receptor, a component involved in the IMD pathway, both in the intestine and fat body; repressing the expression of the relish transcription factor, mainly in salivary glands. Among the R. prolixus AMPs studied, T. rangeli infection repressed all AMP gene expression, other than defensin C which increased mRNA levels. The PO activity was enhanced in the hemolymph of infected insects. T. rangeli infection did not induce hemocyte number alterations compared to control insects. However, an increase in hemocyte microaggregation was detected in infected insects. Discussion: R. prolixus recognizes T. rangeli infection and triggers humoral and cellular immune responses involving Toll pathway activation, defensin C synthesis, increased phenoloxidase activity, and enhanced hemocyte aggregation. On the other hand, T. rangeli infection suppressed some IMD pathway components, suggesting that, in R. prolixus, this pathway is involved in defensins A and B gene regulation. Importantly, these immune responses altered the bacterial microbiota composition, potentially favoring T. rangeli establishment in the insect vector.

Exploring Trypanosoma cruzi transmission dynamics in an acute Chagas disease outbreak using next-generation sequencing.

BACKGROUND: Chagas disease (CD), caused by Trypanosoma cruzi, poses a major global public health challenge. Although vector-borne transmission is the primary mode of infection, oral transmission is increasingly concerning. METHODS: This study utilized long-amplicon-based sequencing (long-ABS), focusing on the 18S rRNA gene, to explore T. cruzi's genetic diversity and transmission dynamics during an acute CD outbreak in Colombia, an area without domestic infestation. RESULTS: Analyzing samples from five patients and five T. cruzi-positive marsupial samples, we identified coinfections between T. cruzi and Trypanosoma rangeli, mixed T. cruzi DTUs, suggesting possible links between human and marsupial T. cruzi infections. Coexistence of TcI, TcIV and T. rangeli suggests marsupial secretions as the possible source of T. cruzi transmission. Our investigation revealed diversity loss in DTUs TcIV and T. rangeli in humans after infection and in marsupial samples after culture. CONCLUSION: These findings provide significant insights into T. cruzi dynamics, crucial for implementing control and prevention strategies.

Trypanosoma rangeli: an alkaline ecto-phosphatase activity is involved with survival and growth of the parasite.

The aim of this work was to investigate whether an alkaline ecto-phosphatase activity is present in the surface of Trypanosoma rangeli. Intact short epimastigote forms were assayed for ecto-phosphatase activity to study kinetics and modulators using ß-glycerophosphate (ß-GP) and p-nitrophenyl phosphate (pNPP) as substrates. Its role in parasite development and differentiation was also studied. Competition assays using different proportions of ß-GP and pNPP evidenced the existence of independent and non-interacting alkaline and acid phosphatases. Hydrolysis of ß-GP increased progressively with pH, whereas the opposite was evident using pNPP. The alkaline enzyme was inhibited by levamisole in a non-competitive fashion. The Ca(2+) present in the reaction medium was enough for full activity. Pretreatment with PI-PLC decreased the alkaline but not the acid phosphatase evidence that the former is catalyzed by a GPI-anchored enzyme, with potential intracellular signaling ability. ß-GP supported the growth and differentiation of T. rangeli to the same extent as high orthophosphate (Pi). Levamisole at the IC50 spared significantly parasite growth when ß-GP was the sole source of Pi and stopped it in the absence of ß-GP, indicating that the alkaline enzyme can utilize phosphate monoesters present in serum. These results demonstrate the existence of an alkaline ecto-phosphatase in T. rangeli with selective requirements and sensitivity to inhibitors that participates in key metabolic processes in the parasite life cycle.

Alterations in energy metabolism of Rhodnius prolixus induced by Trypanosoma rangeli infection.

Trypanosoma rangeli is a protozoan parasite that infects triatomines and mammals in the Americas, producing mixed infections with Trypanosoma cruzi, the etiological agent of Chagas disease. The former parasite is not pathogenic to humans, but has different levels of pathogenicity, as well as causing physiological and behavioral alterations, to its invertebrate hosts. In this study, we measured locomotory activity, and the glyceride accumulation profile in the hemolymph and fat body, as well as the expression of key genes related to triglyceride metabolism, of Rhodnius prolixus nymphs infected with T. rangeli. We found that the locomotory activity of the insects was correlated with the amount of triglycerides in the fat body. Infected nymphs had increased activity when starved, and also had an accumulation of glycerides in the fat body and hemolymph. These alterations were also associated with a higher expression of the diacylglycerol acyltransferase, lipophorin and lipophorin receptor genes in the fat body. We infer that T. rangeli is able to alter the energetic processes of its invertebrate host, in order to increase the availability of lipids to the parasite, which, in turn modifies the activity levels of the insect. These alterations are discussed with regard to their potential to increase the transmission rate of the parasite.

Lipid metabolism dynamic in Triatomine Rhodnius prolixus during acute Trypanosoma rangeli infection.

During its life cycle, Trypanosoma rangeli invades the hemolymph of its invertebrate host and colonizes hemocytes and salivary glands. The parasite cannot synthesize some lipid classes, and during its cycle, it depends on the uptake of these molecules from its vertebrate and invertebrate hosts to meet growth and differentiation requirements. However, until now, knowledge on how the parasite affects the lipid physiology of individual insect organs has been largely unknown. Herein, the biochemical and molecular dynamics of triatomine R. prolixus lipid metabolism in response to acute T. rangeli infection were investigated. Biochemical and microscopic assays revealed the lipid droplet profile and the levels of the different identified lipid classes. In addition, a qRT‒PCR approach was used to determine the expression profile of 6 protein-coding genes involved in the R. prolixus lipid physiology. We observed that triacylglycerol (TAG), monoacylglycerol (MAG), phosphatidylethanolamine (PE) and phosphatidylcholine (PC) levels in the fat body decreased in infected insects. On the other hand, high levels of free fatty acids were observed in the hemolymph during infection. Analysis by confocal microscopy revealed a decrease in lipid droplets size from infected fat bodies, and investigations by scanning electron microscopy revealed a significant number of parasites adhered to the surface of the organ. T. rangeli infection upregulated the transcript levels of the protein-coding gene for the acetyl-CoA carboxylase, the first enzyme in the de novo fatty acid synthesis pathway, responsible for the production of malonyl-CoA. On the other hand, downregulation of lipophorin receptor was observed. In conclusion, this study reveals a new set of molecular events that occur within the vector in response to the challenge imposed by the parasite.