High variation in immune responses and parasite phenotypes in naturally acquired Trypanosoma cruzi infection in a captive non-human primate breeding colony in Texas, USA

AbstractTrypanosoma cruzi, the causative agent of human Chagas disease, is endemic to the southern region of the United States where it routinely infects many host species. The indoor/outdoor housing configuration used in many non-human primate research and breeding facilities in the southern U.S. provides the opportunity for infection by T. cruzi and thus provides source material for in-depth investigation of host and parasite dynamics in a natural host species under highly controlled and restricted conditions. For cynomolgus macaques housed at such a facility, we used a combination of serial blood quantitative PCR (qPCR) and hemoculture to confirm infection in >92% of seropositive animals, although each method alone failed to detect infection in >20% of cases. Parasite isolates obtained from 43 of the 64 seropositive macaques were of 2 broad genetic types (discrete typing units, (DTU’s) I and IV); both within and between these DTU groupings, isolates displayed a wide variation in growth characteristics and virulence, elicited host immune responses, and susceptibility to drug treatment in a mouse model. Likewise, the macaques displayed a diversity in T cell and antibody response profiles that rarely correlated with parasite DTU type, length of infection, or age of the primate. This study reveals the complexity of infection dynamics, parasite phenotypes, and immune response patterns that can occur in a primate group, despite being housed in a uniform environment at a single location, and the limited time period over which the T. cruzi infections were established.Author SummaryWe evaluated naturally occurring infections of Trypanosoma cruzi, the causative agent of human Chagas disease, in an indoor/outdoor primate colony at a breeding facility in Texas, USA. Using serial quantitative PCR and hemoculture, we confirmed infection in 92% of the 64 seropositive animals, but neither of these two methods confirmed more than 80% of the cases. Parasites by hemoculture fell into two genetic groups (discrete typing units I and IV), and displayed large variation in growth characteristics, elicited cellular and humoral immune responses as well as virulence and drug susceptibility when tested in mice. EKG abnormalities were found in 13 out of 51 qPCR-positive macaques. Our results demonstrate the complexity of these infection parameters in this colony in spite of the uniform and geographically constrained housing conditions of the macaques.

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High variation in immune responses and parasite phenotypes in naturally acquired Trypanosoma cruzi infection in a captive non-human primate breeding colony in Texas, USA

PLoS Neglected Tropical Diseases ◽

10.1371/journal.pntd.0009141 ◽

2021 ◽

Vol 15 (3) ◽

pp. e0009141

Author(s):

Angel M. Padilla ◽

Phil Y. Yao ◽

Tre J. Landry ◽

Gretchen M. Cooley ◽

Susan M. Mahaney ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Immune Responses ◽

Host Species ◽

The United States ◽

Minimum Length ◽

Primate Research ◽

Infection Dynamics ◽

Natural Host Species ◽

The Usa ◽

Human Primate

Trypanosoma cruzi, the causative agent of human Chagas disease, is endemic to the southern region of the United States where it routinely infects many host species. The indoor/outdoor housing configuration used in many non-human primate research and breeding facilities in the southern of the USA provides the opportunity for infection by T. cruzi and thus provides source material for in-depth investigation of host and parasite dynamics in a natural host species under highly controlled and restricted conditions. For cynomolgus macaques housed at such a facility, we used a combination of serial blood quantitative PCR (qPCR) and hemoculture to confirm infection in >92% of seropositive animals, although each method alone failed to detect infection in >20% of cases. Parasite isolates obtained from 43 of the 64 seropositive macaques were of 2 broad genetic types (discrete typing units, (DTU’s) I and IV); both within and between these DTU groupings, isolates displayed a wide variation in growth characteristics and virulence, elicited host immune responses, and susceptibility to drug treatment in a mouse model. Likewise, the macaques displayed a diversity in T cell and antibody response profiles that rarely correlated with parasite DTU type, minimum length of infection, or age of the primate. This study reveals the complexity of infection dynamics, parasite phenotypes, and immune response patterns that can occur in a primate group, despite being housed in a uniform environment at a single location, and the limited time period over which the T. cruzi infections were established.

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Humoral and Cellular Immune Responses to Trypanosoma cruzi-Derived Paraflagellar Rod Proteins in Patients with Chagas' Disease

Infection and Immunity ◽

10.1128/iai.71.6.3165-3171.2003 ◽

2003 ◽

Vol 71 (6) ◽

pp. 3165-3171 ◽

Cited By ~ 34

Author(s):

Vladimir Michailowsky ◽

Keith Luhrs ◽

Manoel Otávio C. Rocha ◽

David Fouts ◽

Ricardo T. Gazzinelli ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Immune Responses ◽

Chagas Disease ◽

Mononuclear Cells ◽

Clinical Symptoms ◽

Cellular Responses ◽

Peripheral Blood Mononuclear ◽

Cellular Immune Responses ◽

Ifn Γ ◽

Cellular Immune

ABSTRACT Sera and peripheral blood mononuclear cells (PBMC) from patients displaying different clinical symptoms as well as from normal uninfected individuals (NI) were used to evaluate the humoral and cellular responses of Chagas' disease patients to Trypanosoma cruzi-derived paraflagellar rod proteins (PFR). Our results show that sera from both asymptomatic Chagas' disease patients (ACP) and cardiac Chagas' disease patients (CCP) have higher levels of antibodies to PFR than sera from NI. Immunoglobulin G1 (IgG1) and IgG3 were the main Ig isotypes that recognized PFR. We also tested three recombinant forms of PFR, named rPAR-1, rPAR-2, and rPAR-3, by Western blot analysis. Sera from seven out of eight patients with Chagas' disease recognized one of the three rPAR forms. Sera from 75, 50, and 37.5% of Chagas' disease patients tested recognized rPAR-3, rPAR-2, and rPAR-1, respectively. PFR induced proliferation of 100 and 70% of PBMC from ACP and CCP, respectively. Further, stimulation of cells from Chagas' disease patients with PFR enhanced the frequencies of both small and large CD4+ CD25+ and CD4+ CD69+ lymphocytes, as well as that of small CD8+ CD25+ lymphocytes. Finally, we evaluated the ability of PFR to elicit the production of gamma interferon (IFN-γ) by PBMC from patients with Chagas' disease. Fifty percent of the PBMC from ACP as well as CCP produced IFN-γ upon stimulation with PFR. PFR enhanced the percentages of IFN-γ-producing cells in both CD3+ and CD3− populations. Within the T-cell population, large CD4+ T lymphocytes were the main source of IFN-γ.

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The United States Trypanosoma cruzi Infection Study: evidence for vector-borne transmission of the parasite that causes Chagas disease among United States blood donors

Transfusion ◽

10.1111/j.1537-2995.2012.03581.x ◽

2012 ◽

Vol 52 (9) ◽

pp. 1922-1930 ◽

Cited By ~ 103

Author(s):

Paul T. Cantey ◽

Susan L. Stramer ◽

Rebecca L. Townsend ◽

Hany Kamel ◽

Karen Ofafa ◽

...

Keyword(s):

United States ◽

Trypanosoma Cruzi ◽

Chagas Disease ◽

Blood Donors ◽

The United States ◽

Vector Borne ◽

Cruzi Infection ◽

Infection Study

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Dispersal patterns of Trypanosoma cruzi in Arequipa, Peru

10.1101/838235 ◽

2019 ◽

Author(s):

Alexander S.F. Berry ◽

Renzo Salazar-Sánchez ◽

Ricardo Castillo-Neyra ◽

Katty Borrini-Mayorí ◽

Claudia Arevalo-Nieto ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Causative Agent ◽

Animal Movement ◽

Protozoan Parasite ◽

Domestic Animal ◽

Urban Environments ◽

Urban Landscapes ◽

Population Genomic ◽

The City

AbstractAnthropogenic environmental alterations such as urbanization can threaten native populations as well as create novel environments that allow human pests and pathogens to thrive. As the number and size of urban environments increase globally, it is more important than ever to understand the dispersal dynamics of hosts, vectors and pathogens of zoonotic disease systems. For example, a protozoan parasite and the causative agent of Chagas disease in humans, Trypanosoma cruzi, recently colonized and spread through the city of Arequipa, Peru. We used population genomic and phylogenomic tools to analyze whole genomes of 123 T. cruzi isolates collected throughout Arequipa to determine patterns of T. cruzi dispersal. The data show significant population genetic structure within city blocks-parasites in the same block tend to be very closely related - but no population structure among blocks within districts - parasites in neighboring blocks are no more closely related to one another than to parasites in distant districts. These data suggest that T. cruzi dispersal within a block occurs regularly and that occasional long-range dispersal events allow the establishment of new T. cruzi populations in distant blocks. Movement of domestic animals may be the primary mechanism of inter-block and inter-district T. cruzi dispersal.Author SummaryUrbanization creates environments that are ideal for some human pests and pathogens. As the number and size of urban environments increases globally, it is becoming vital to understand how human disease-causing pathogens, their vectors, and their non-human hosts disperse through urban landscapes. Here we study a population of Trypanosoma cruzi – the protozoan parasite and causative agent of Chagas disease in humans – that recently colonized the city of Arequipa, Peru. We use population genomic and phylogenomic tools to understand how this parasite population dispersed through the city to achieve its current distribution and abundance. We show that T. cruzi collected from the same city block tend to be very closely related, while those from neighboring blocks are often as distantly related as those from blocks in distant districts. The data suggest that vectors facilitate frequent within-block dispersal of the parasite, while domestic animal movement may facilitate the relatively infrequent inter-block and interdistrict dispersal.

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Is It Possible to Intervene in the Capacity of Trypanosoma cruzi to Elicit and Evade the Complement System?

Frontiers in Immunology ◽

10.3389/fimmu.2021.789145 ◽

2021 ◽

Vol 12 ◽

Author(s):

Galia Ramírez-Toloza ◽

Lorena Aguilar-Guzmán ◽

Carolina Valck ◽

Smrithi S. Menon ◽

Viviana P. Ferreira ◽

...

Keyword(s):

Latin America ◽

Trypanosoma Cruzi ◽

Immune Responses ◽

Chagas Disease ◽

Complement System ◽

Significant Inhibition ◽

Transplacental Transmission ◽

Global Expansion ◽

The Complement System ◽

Evasive Strategy

Chagas’ disease is a zoonotic parasitic ailment now affecting more than 6 million people, mainly in Latin America. Its agent, the protozoan Trypanosoma cruzi, is primarily transmitted by endemic hematophagous triatomine insects. Transplacental transmission is also important and a main source for the emerging global expansion of this disease. In the host, the parasite undergoes intra (amastigotes) and extracellular infective (trypomastigotes) stages, both eliciting complex immune responses that, in about 70% of the cases, culminate in permanent immunity, concomitant with the asymptomatic presence of the parasite. The remaining 30% of those infected individuals will develop a syndrome, with variable pathological effects on the circulatory, nervous, and digestive systems. Herein, we review an important number of T. cruzi molecules, mainly located on its surface, that have been characterized as immunogenic and protective in various experimental setups. We also discuss a variety of parasite strategies to evade the complement system - mediated immune responses. Within this context, we also discuss the capacity of the T. cruzi infective trypomastigote to translocate the ER-resident chaperone calreticulin to its surface as a key evasive strategy. Herein, it is described that T. cruzi calreticulin inhibits the initial stages of activation of the host complement system, with obvious benefits for the parasite. Finally, we speculate on the possibility to experimentally intervene in the interaction of calreticulin and other T. cruzi molecules that interact with the complement system; thus resulting in significant inhibition of T. cruzi infectivity.

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The Blockade of Interleukin-2 During the Acute Phase of Trypanosoma cruzi Infection Reveals Its Dominant Regulatory Role

Frontiers in Cellular and Infection Microbiology ◽

10.3389/fcimb.2021.758273 ◽

2021 ◽

Vol 11 ◽

Author(s):

Jorge Nihei ◽

Fabiola Cardillo ◽

Jose Mengel

Keyword(s):

Immune Response ◽

T Cells ◽

Regulatory T Cells ◽

Trypanosoma Cruzi ◽

Immune Responses ◽

Chagas Disease ◽

Acute Phase ◽

Acute Infection ◽

Dependent Manner ◽

Tissue Specific

Trypanosoma cruzi infection causes Chagas’ disease in humans. The infection activates the innate and adaptative immunity in an orchestrated immune response to control parasite growth, guaranteeing host survival. Despite an effective immune response to the parasite in the acute phase, the infection progresses to a chronic stage. The parasite infects different tissues such as peripheral neurons, the brain, skeletal muscle, and heart muscle, among many others. It is evident now that tissue-specific immune responses may develop along with anti-parasite immunity. Therefore, mechanisms to regulate immunity and to ensure tissue-specific tolerance are operating during the infection. Studying those immunoregulatory mechanisms is fundamental to improve host protection or control inflammatory reactions that may lead to pathology. The role of IL-2 during T. cruzi infection is not established. IL-2 production by T cells is strongly down-modulated early in the disease by unknown mechanisms and remains low during the chronic phase of the disease. IL-2 activates NK cells, CD4, and CD8 T cells and may be necessary to immunity development. Also, the expansion and maintenance of regulatory T cells require IL-2. Thus, IL-2 may be a key cytokine involved in promoting or down-regulating immune responses, probably in a dose-dependent manner. This study blocked IL-2 during the acute T. cruzi infection by using a neutralizing monoclonal antibody. The results show that parasitemia and mortality rate was lower in animals treated with anti-IL-2. The percentages and total numbers of CD4+CD25+Foxp3+ T cells diminished within three weeks of infection. The numbers of splenic activated/memory CD4 and CD8 splenic T cells increased during the acute infection. T cells producing IFN-γ, TNF-α and IL-10 also augmented in anti-IL-2-treated infected mice. The IL-2 blockade also increased the numbers of inflammatory cells in the heart and skeletal muscles and the amount of IL-17 produced by heart T cells. These results suggest that IL-2 might be involved in the immune regulatory response during the acute T. cruzi infection, dampening T cell activation through the expansion/maintenance of regulatory T cells and regulating IL-17 production. Therefore, the IL-2 pathway is an attractive target for therapeutic purposes in acute and chronic phases of Chagas’ disease.

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Discovery and Optimization of a Compound Series Active against Trypanosoma cruzi, the Causative Agent of Chagas Disease

Journal of Medicinal Chemistry ◽

10.1021/acs.jmedchem.9b01852 ◽

2020 ◽

Vol 63 (6) ◽

pp. 3066-3089

Author(s):

Justin R. Harrison ◽

Sandipan Sarkar ◽

Shahienaz Hampton ◽

Jennifer Riley ◽

Laste Stojanovski ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Causative Agent ◽

Compound Series

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1357. A Combination of Itraconazole and Amiodarone Is Highly Effective Against Trypanosoma cruzi Infection of Human Stem Cell-Derived Cardiomyocytes

Open Forum Infectious Diseases ◽

10.1093/ofid/ofy210.1188 ◽

2018 ◽

Vol 5 (suppl_1) ◽

pp. S415-S416

Author(s):

Gabriele Sass ◽

Roy Madigan ◽

Adriana Bozzi ◽

Nazish Sayed ◽

Joseph Wu ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Cell Metabolism ◽

Vero Cells ◽

The United States ◽

Etiologic Agent ◽

Sterol Synthesis ◽

Xtt Assay ◽

Cruzi Infection

Abstract Background Trypanosoma cruzi is the etiologic agent of Chagas disease, which can result in severe cardiomyopathy. Trypanosoma cruzi is endemic to the Americas, and of particular importance in Latin America. In the United States and other nonendemic countries, rising case numbers have been observed. The only drugs available so far are benznidazole and nifurtimox, which have limited efficacy during chronic infection. We repurposed itraconazole, originally an antifungal, in combination with amiodarone, an antiarrhythmic, with the goal to interfere with Tc infection. Both drugs inhibit sterol synthesis, while amiodarone also inhibits calcium metabolism of Trypanosoma cruzi. Methods Human pluripotent stem cells (HiPSC) were differentiated to cardiomyocytes (HiPSC-CM). Vero cells or HiPSC-CM were infected with the T. cruzi trypomastigotes Y strain in the presence of itraconazole and/or amiodarone. After 48 hours, infection and multiplication were evaluated by Giemsa stain. Benznidazole was used as a reference compound. Cell viability was verified by XTT assay. Results Itraconazole and amiodarone showed dose-dependent interference with T. cruzi infection of Vero cells or HiPSC-CM. The combination of itraconazole and amiodarone was more potent than the single substances, or benznidazole at therapeutic concentrations, without affecting host cell metabolism. In addition to effects on infection, itraconazole, or amiodarone affected T. cruzi multiplication. Here, itraconazole/amiodarone combinations were more potent than either alone, both, in Vero cells, and HiPSC-CM. Conclusion Our in vitro data suggest that a combination of itraconazole and amiodarone might serve as an effective new treatment option for Chagas disease, particularly cardiac involvement, in human and animal patients. Disclosures All authors: No reported disclosures.

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Comparative high-throughput analysis of the Trypanosoma cruzi response to organometallic compounds

Metallomics ◽

10.1039/d0mt00030b ◽

2020 ◽

Vol 12 (5) ◽

pp. 813-828

Author(s):

M. Florencia Mosquillo ◽

Pablo Smircich ◽

Martín Ciganda ◽

Analía Lima ◽

Dinorah Gambino ◽

...

Keyword(s):

Gene Expression ◽

Trypanosoma Cruzi ◽

Expression Pattern ◽

Chagas Disease ◽

High Throughput ◽

Causative Agent ◽

Gene Expression Pattern ◽

Organometallic Compounds ◽

Global Gene Expression ◽

High Throughput Analysis

An in-depth, comparative look at the effects of two structurally related organometallic Pd and Pt compounds on the global gene expression pattern of T. cruzi epimastigotes. This parasite is the causative agent of Chagas disease.

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