A Trypanosoma cruzi Small Surface Molecule Provides the First Immunological Evidence that Chagas' Disease Is Due to a Single Parasite Lineage

Chagas' disease is a major health and economic problem caused by the protozoan Trypanosoma cruzi. Multiple independently evolving clones define a complex parasite population that can be arranged into two broad genetic lineages termed T. cruzi I and II. These lineages have different evolutionary origin and display distinct ecological and biological traits. Here we describe a novel molecule termed TSSA for trypomastigote small surface antigen that provides the first immunological marker allowing discrimination between lineages. TSSA is a surface, glycosylphosphatidyl inositol (GPI)-anchored mucin-like protein, highly antigenic during the infection. TSSA sequences from different parasite isolates reveal a population dimorphism that perfectly matches with the two T. cruzi lineages. Interestingly, this dimorphism is restricted to the central region of the molecule, which comprises the immunodominant B cell epitopes. This sequence variability has a major impact on TSSA antigenicity, leading to no immunological cross-reactivity between both isoforms for antibodies present either in immunization or infection sera. Furthermore, the absolute seroprevalence for TSSA in confirmed Chagasic patients is restricted to T. cruzi II isoform, strongly suggesting that human infections are due to this particular subgroup. Even though association of T. cruzi II with Chagas' disease has been proposed based on molecular markers, this is the first immunological evidence supporting this hypothesis. The implications of these results for the future research on Chagas' disease could be envisaged.

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Evaluation of a Recombinant Trypanosoma cruzi Mucin-Like Antigen for Serodiagnosis of Chagas' Disease

Clinical and Vaccine Immunology ◽

10.1128/cvi.05289-11 ◽

2011 ◽

Vol 18 (11) ◽

pp. 1850-1855 ◽

Cited By ~ 35

Author(s):

Claudia R. De Marchi ◽

Javier M. Di Noia ◽

Alberto C. C. Frasch ◽

Vicente Amato Neto ◽

Igor C. Almeida ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

The United States ◽

Cross Reactivity ◽

Immunofluorescence Assay ◽

Health Concern ◽

Enzyme Linked Immunosorbent Assay ◽

Serological Tests ◽

Small Surface ◽

Content Type

ABSTRACTChagas' disease is caused by the protozoan parasiteTrypanosoma cruziand is one of the most important endemic problems in Latin America. Lately, it has also become a health concern in the United States and Europe. Currently, a diagnosis of Chagas' disease and the screening of blood supplies for antiparasite antibodies are achieved by conventional serological tests that show substantial variation in the reproducibility and reliability of their results. In addition, the specificity of these assays is curtailed by antigenic cross-reactivity with sera from patients affected by other endemic diseases, such as leishmaniasis. Here we used a highly sensitive chemiluminescent enzyme-linked immunosorbent assay (CL-ELISA) to evaluate a recombinant protein core of a mucin-like molecule (termed trypomastigote small surface antigen [TSSA]) for the detection of specific serum antibodies in a broad panel of human sera. The same samples were evaluated by CL-ELISA using as the antigen either a mixture of nativeT. cruzitrypomastigote mucins or an epimastigote extract and, for further comparison, by conventional serologic tests, such as an indirect hemagglutination assay and indirect immunofluorescence assay. TSSA showed ∼87% sensitivity among the seropositive Chagasic panel, a value which was increased up to >98% when only parasitologically positive samples were considered. More importantly, TSSA showed a significant increase in specificity (97.4%) compared to those of currently used assays, which averaged 80 to 90%. Overall, our data demonstrate that recombinant TSSA may be a useful antigen for the immunodiagnosis of Chagas' disease.

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Trypanosoma cruzi: identification of specific epimastigote antigens by human immune sera

Memórias do Instituto Oswaldo Cruz ◽

10.1590/s0074-02761989000300004 ◽

1989 ◽

Vol 84 (3) ◽

pp. 309-314 ◽

Cited By ~ 5

Author(s):

M. G. Morgado ◽

J. Ivo-dos-Santos ◽

R. T. Pinho ◽

E. Argüelles ◽

J. M. Rezende ◽

...

Keyword(s):

Visceral Leishmaniasis ◽

Trypanosoma Cruzi ◽

Western Blot ◽

Chagas Disease ◽

Cross Reactivity ◽

Cross Reaction ◽

The Other ◽

Molecular Weights ◽

Human Visceral Leishmaniasis ◽

Human Immune

Soluble antigens from epimastigotes of Trypanosoma cruzi were analyzed by western blot in terms of their reactivity with sera from patients with Chagas' disease. In addition, sera from patients with visceral (AVL) and tegumentar leishmaniasis (ATL) were also tested in order to identify cross-reactivities with Trypanosoma cruzy antigens. Twenty eight polypeptides with molecular weights ranging from 14 kDa to 113 kDa were identified with sera from Chagas' disease patients. An extensive cross-reactivity was observed when sera from human visceral leishmaniasis were used, while only a slight cross-reaction was observed with sera from tegumentar leishmaniasis. On the other hand, 10 polypeptidesspecifically reacting with sera from Chagas' disease patients were identified. Among them, the antigens with molecular weights of 46 kDa and 25 kDa reacted with all sera teste and may be good candidates for specific immunodiagnosis of Chagas' disease.

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Glycosylation of Trypanosoma cruzi TcI antigen reveals recognition by chagasic sera

Scientific Reports ◽

10.1038/s41598-020-73390-9 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Niamh Murphy ◽

Barrie Rooney ◽

Tapan Bhattacharyya ◽

Omar Triana-Chavez ◽

Anja Krueger ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Periodate Oxidation ◽

Heat Denaturation ◽

Parasitic Disease ◽

Small Surface ◽

Genetic Lineages ◽

Gastrointestinal Pathology ◽

Endemic Malaria ◽

Clinical Presentations ◽

Host Tissues

Abstract Chagas disease is considered the most important parasitic disease in Latin America. The protozoan agent, Trypanosoma cruzi, comprises six genetic lineages, TcI-TcVI. Genotyping to link lineage(s) to severity of cardiomyopathy and gastrointestinal pathology is impeded by the sequestration and replication of T. cruzi in host tissues. We describe serology specific for TcI, the predominant lineage north of the Amazon, based on expression of recombinant trypomastigote small surface antigen (gTSSA-I) in the eukaryote Leishmania tarentolae, to allow realistic glycosylation and structure of the antigen. Sera from TcI-endemic regions recognised gTSSA-I (74/146; 50.7%), with no cross reaction with common components of gTSSA-II/V/VI recombinant antigen. Antigenicity was abolished by chemical (periodate) oxidation of gTSSA-I glycosylation but retained after heat-denaturation of conformation. Conversely, non-specific recognition of gTSSA-I by non-endemic malaria sera was abolished by heat-denaturation. TcI-specific serology facilitates investigation between lineage and diverse clinical presentations. Glycosylation cannot be ignored in the search for immunogenic antigens.

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The Trypomastigote Small Surface Antigen from Trypanosoma cruzi Improves Treatment Evaluation and Diagnosis in Pediatric Chagas Disease

Journal of Clinical Microbiology ◽

10.1128/jcm.01317-17 ◽

2017 ◽

Vol 55 (12) ◽

pp. 3444-3453 ◽

Cited By ~ 8

Author(s):

Virginia Balouz ◽

Luciano J. Melli ◽

Romina Volcovich ◽

Guillermo Moscatelli ◽

Samanta Moroni ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Surface Antigen ◽

Rapid Assessment ◽

Drug Efficacy ◽

Enzyme Linked Immunosorbent Assay ◽

Serological Tests ◽

Small Surface ◽

Content Type

ABSTRACTChagas disease is caused by the protozoan parasiteTrypanosoma cruzi. Assessment of parasitological cure upon treatment with available drugs relies on achieving consistent negative results in conventional parasitological and serological tests, which may take years to assess. Here, we evaluated the use of a recombinantT. cruziantigen termed trypomastigote small surface antigen (TSSA) as an early serological marker of drug efficacy inT. cruzi-infected children. A cohort of 78 pediatric patients born toT. cruzi-infected mothers was included in this study. Only 39 of the children were infected withT. cruzi, and they were immediately treated with trypanocidal drugs. Serological responses against TSSA were evaluated in infected and noninfected populations during the follow-up period using an in-house enzyme-linked immunosorbent assay (ELISA) and compared to conventional serological methods. Anti-TSSA antibody titers decreased significantly faster than anti-whole parasite antibodies detected by conventional serology both inT. cruzi-infected patients undergoing effective treatment and in those not infected. The differential kinetics allowed a significant reduction in the required follow-up periods to evaluate therapeutic responses or to rule out maternal-fetal transmission. Finally, we present the case of a congenitally infected patient with an atypical course in whom TSSA provided an early marker forT. cruziinfection. In conclusion, we showed that TSSA was efficacious both for rapid assessment of treatment efficiency and for early negative diagnosis in infants at risk of congenitalT. cruziinfection. Based upon these findings we propose the inclusion of TSSA for refining the posttherapeutic cure criterion and other diagnostic needs in pediatric Chagas disease.

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BloodstreamTrypanosoma cruziparasites from mice simultaneously express antigens that are markers of acute and chronic human Chagas disease

Parasitology ◽

10.1017/s0031182000064337 ◽

1991 ◽

Vol 102 (3) ◽

pp. 379-385 ◽

Cited By ~ 8

Author(s):

M. S. Leguizamon ◽

O. E. Campetella ◽

M. B. Reyes ◽

C. F. Ibañez ◽

M. A. Basombrio ◽

...

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Acute Phase ◽

Early Period ◽

Chronic Phase ◽

Blood Parasites ◽

Expression Library ◽

Antibody Specificities ◽

Human Infections ◽

Parasite Strains

Several recombinantTrypanosoma cruziproteins previously isolated were used as antigens to analyse antibody specificities present in sera from human infections. Some parasite proteins such as SAPA (Shed Acute Phase Antigen) are antigenic early after infection. Others, like antigens 1 and 30, are antigenic mainly during the chronic phase of the infection. To understand why different proteins are antigenic at different periods of infection, specificities of antibodies present in the sera of infected mice were compared with the antigens expressed by parasites collected directly from blood. Parasites collected during the acute parasitaemia peak expressed not only antigen SAPA, but also antigens 1 and 30. However, only antibodies against SAPA were frequently observed during the early period and also in the chronic phase of murine infection. Long-lasting antibodies against SAPA were detected regardless of the mouse and parasite strains used. Furthermore, all 8 recombinant clones detected in aT. cruziexpression library with pooled sera from acutely infected mice were homologous to the SAPA gene. These results show that even though parasites from the acute parasitaemia peak in mice may express simultaneously several proteins known to be antigenic, only antibodies against SAPA were consistently detected.

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Cross-reactivity of antibodies in human infections by the kinetoplastid protozoa Trypanosoma cruzi, Leishmania chagasi and Leishmania (Viannia) braziliensis

Revista do Instituto de Medicina Tropical de São Paulo ◽

10.1590/s0036-46651996000300003 ◽

1996 ◽

Vol 38 (3) ◽

pp. 177-185 ◽

Cited By ~ 51

Author(s):

Ana de Cássia Vexenat ◽

Jaime M. Santana ◽

Antonio R.L. Teixeira

Keyword(s):

Trypanosoma Cruzi ◽

Chagas Disease ◽

Cross Reactivity ◽

Antigenic Determinants ◽

Leishmania Braziliensis ◽

Leishmania Chagasi ◽

Mucocutaneous Leishmaniasis ◽

Kala Azar ◽

Homologous Antigen ◽

Positive Results

We have detected antibodies, in the sera of Chagas disease, Kala-azar and Mucocutaneous leishmaniasis patients, that bind multiple antigens shared between the three causative agents. The Chagas disease sera showed 98 to 100% positive results by ELISA when the Leishmania braziliensis and Leishmania chagasi antigens were used, respectively. The Kala-azar sera showed 100% positive results with Trypanosoma cruzi or L. braziliensis antigens by immunofluorescence assays. The antibodies in the sera of Mucocutaneous leishmaniasis patients showed 100% positive results by ELISA assays with T. cruzi or L. chagasi antigens. Furthermore, the direct agglutination of L. chagasi promastigotes showed that 95% of Kala-azar and 35% of Mucocutaneous leishmaniasis sera agglutinated the parasite in dilutions above 1:512. In contrast, 15% of Chagas sera agglutinated the parasite in dilutions 1:16 and below. Western blot analysis showed that the Chagas sera that formed at least 24 bands with the T. cruzi also formed 13 bands with the L. chagasi and 17 bands with the L. braziliensis. The Kala-azar sera that recognized at least 29 bands with the homologous antigen also formed 14 bands with the T. cruzi and 10 bands with the L. braziliensis antigens. Finally, the Mucocutaneous leishmaniasis sera that formed at least 17 bands with the homologous antigen also formed 10 bands with the T. cruzi and four bands with the L. chagasi antigens. These results indicate the presence of common antigenic determinants in several protozoal proteins and, therefore, explain the serologic cross-reactions reported here.

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Mapping Antigenic Motifs in the Trypomastigote Small Surface Antigen from Trypanosoma cruzi

Clinical and Vaccine Immunology ◽

10.1128/cvi.00684-14 ◽

2015 ◽

Vol 22 (3) ◽

pp. 304-312 ◽

Cited By ~ 21

Author(s):

Virginia Balouz ◽

María de los Milagros Cámara ◽

Gaspar E. Cánepa ◽

Santiago J. Carmona ◽

Romina Volcovich ◽

...

Keyword(s):

Amino Acid ◽

Trypanosoma Cruzi ◽

Chagas Disease ◽

Surface Antigen ◽

Humoral Response ◽

Antigenic Structure ◽

Antigenic Determinants ◽

Small Surface ◽

Content Type ◽

Surface Receptors

ABSTRACTThe trypomastigote small surface antigen (TSSA) is a mucin-like molecule fromTrypanosoma cruzi, the etiological agent of Chagas disease, which displays amino acid polymorphisms in parasite isolates. TSSA expression is restricted to the surface of infective cell-derived trypomastigotes, where it functions as an adhesin and engages surface receptors on the host cell as a prerequisite for parasite internalization. Previous results have established TSSA-CL, the isoform encoded by the CL Brener clone, as an appealing candidate for use in serology-based diagnostics for Chagas disease. Here, we used a combination of peptide- and recombinant protein-based tools to map the antigenic structure of TSSA-CL at maximal resolution. Our results indicate the presence of different partially overlapping B-cell epitopes clustering in the central portion of TSSA-CL, which contains most of the polymorphisms found in parasite isolates. Based on these results, we assessed the serodiagnostic performance of a 21-amino-acid-long peptide that spans TSSA-CL major antigenic determinants, which was similar to the performance of the previously validated glutathioneS-transferase (GST)-TSSA-CL fusion molecule. Furthermore, the tools developed for the antigenic characterization of the TSSA antigen were also used to explore other potential diagnostic applications of the anti-TSSA humoral response in Chagasic patients. Overall, our present results provide additional insights into the antigenic structure of TSSA-CL and support this molecule as an excellent target for molecular intervention in Chagas disease.

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Cross-reactivity studies and differential serodiagnosis of human infections caused by Trypanosoma cruzi and Leishmania spp; use of immunoblotting and ELISA with a purified antigen (Ag163B6)

Clinical & Experimental Immunology ◽

10.1111/j.1365-2249.1994.tb06104.x ◽

2008 ◽

Vol 97 (3) ◽

pp. 417-423 ◽

Cited By ~ 45

Author(s):

E. L. MALCHIODI ◽

M. G. CHIARAMONTE ◽

N. J. TARANTO ◽

N. W. ZWIRNER ◽

R. A. MARGNI

Keyword(s):

Trypanosoma Cruzi ◽

Cross Reactivity ◽

Leishmania Spp ◽

Purified Antigen ◽

Human Infections

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Phylogenetic diversity of two common Trypanosoma cruzi lineages in the Southwestern United States

10.1101/2021.11.10.468115 ◽

2021 ◽

Author(s):

Carlos A Flores-Lopez ◽

Elizabeth A Mitchell ◽

Carolina E Reisenman ◽

Sahotra Sarkar ◽

Philip C Williamson ◽

...

Keyword(s):

Genetic Diversity ◽

Trypanosoma Cruzi ◽

Chagas Disease ◽

Sequence Data ◽

Sequence Divergence ◽

Single Copy ◽

High Genetic Diversity ◽

Genetic Lineages ◽

Control Programs ◽

The Usa

Trypanosoma cruzi is the causative agent of Chagas disease, a devastating parasitic disease endemic to Central and South America, Mexico, and the USA. We characterized the genetic diversity of T. cruzi circulating in five triatomine species (Triatoma gerstaeckeri, T. lecticularia, T. indictiva, T. sanguisuga and T. recurva) collected in Texas and Southern Arizona using nucleotide sequences from four single-copy loci (COII-ND1, MSH2, DHFR-TS, TcCLB.506529.310). All T. cruzi variants fall in two main genetic lineages: 75% of the samples corresponded to T. cruzi Discrete Typing Unit (DTU) I (TcI), and 25% to a North American specific lineage previously labelled TcIV-USA. Phylogenetic and sequence divergence analyses of our new data plus all previously published sequence data from those 4 genes collected in the USA, show that TcIV-USA is significantly different from any other previously defined T. cruzi DTUs. The significant level of genetic divergence between TcIV-USA and other T. cruzi lineages should lead to an increased focus on understanding the epidemiological importance of this lineage, as well as its geographical range and pathogenicity in humans and domestic animals. Our findings further corroborate the fact that there is a high genetic diversity of the parasite in North America and emphasize the need for appropriate surveillance and vector control programs for Chagas disease in southern USA and Mexico.

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