Evidence map›Paper›PMID 27055052›Full record

ArticlePLoS neglected tropical diseases2016

Characterization of Calflagin, a Flagellar Calcium-Binding Protein from Trypanosoma congolense.

Brett A Eyford, Laura Kaufman, Orly Salama-Alber, Bianca Loveless, Matthew E Pope, Robert D Burke, Enock Matovu, Martin J Boulanger, Terry W Pearson

Open access · goldAbstract read
In one paragraph

Article in PLoS neglected tropical diseases, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 1 paper.

0numbers the graph read from it
0cells of the map it votes in
1citing papers in PubMed
–field-weighted citation impact, top 97% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

1 citing paper in PubMed, 4 citations in OpenAlex.

  1. Article
4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

9 authors at 2 institutions in 2 countries.

Brett A EyfordDepartment of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.
Laura KaufmanDepartment of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.
Orly Salama-AlberDepartment of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.
Bianca LovelessDepartment of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.
Matthew E PopeDepartment of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.
Robert D BurkeDepartment of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.
Enock MatovuCollege of Veterinary Medicine, Animal Resources and Biosecurity, Makerere University, Kampala, Uganda.
Martin J BoulangerDepartment of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.
Terry W PearsonDepartment of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada.
University of Victoria · CAMakerere University · UG

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundIdentification of species-specific trypanosome molecules is important for laboratory- and field-based research into epidemiology and disease diagnosis. Although Trypanosoma congolense is the most important trypanosome pathogen of cattle in Africa, no species-specific molecules found in infective bloodstream forms (BSF) of the parasites have been identified, thus limiting development of diagnostic tests.

methodsImmuno-mass spectrometric methods were used to identify a protein that is recognized by a T. congolense-specific monoclonal antibody (mAb) Tc6/42.6.4. The identified molecule was expressed as a recombinant protein in E. coli and was tested in several immunoassays for its ability to interact with the mAb. The three dimensional structure of the protein was modeled and compared to crystal- and NMR-structures of the homologous proteins from T. cruzi and T. brucei respectively, in order to examine structural differences leading to the different immunoreactivity of the T. congolense molecule. Enzyme-linked immunosorbent assays (ELISA) were used to measure antibodies produced by trypanosome-infected African cattle in order to assess the potential for use of T. congolense calflagin in a serodiagnostic assay.

resultsThe antigen recognized by the T. congolense-specific mAb Tc6/42.6.4 was identified as a flagellar calcium-binding protein, calflagin. The recombinant molecule showed immunoreactivity with the T. congolense-specific mAb confirming that it is the cognate antigen. Immunofluorescence experiments revealed that Ca2+ modulated the localization of the calflagin molecule in trypanosomes. Structural modelling and comparison with calflagin homologues from other trypanosomatids revealed four non-conserved regions on the surface of the T. congolense molecule that due to differences in surface chemistry and structural topography may form species-specific epitopes. ELISAs using the recombinant calflagin as antigen to detect antibodies in trypanosome-infected cattle showed that the majority of cattle had antibody responses. Area under the Receiver-Operating Characteristic (ROC) curves, associated with host IgG and IgM, were calculated to be 0.623 and 0.709 respectively, indicating a positive correlation between trypanosome infection and the presence of anti-calflagin antibodies.

conclusionsWhile calflagin is conserved among different species of African trypanosomes, our results show that T. congolense calflagin possesses unique epitopes that differentiate this protein from homologues in other trypanosome species. MAb Tc6/42.6.4 has clear utility as a laboratory tool for identifying T. congolense. T. congolense calflagin has potential as a serodiagnostic antigen and should be explored further for its utility in antigen-detection assays for diagnosis of cattle infections.

Indexed as

AnimalsAntibodies, MonoclonalAntibodies, ProtozoanAntigens, ProtozoanCalcium-Binding ProteinsCattleEnzyme-Linked Immunosorbent AssayEpitope MappingEscherichia coliMass SpectrometryModels, MolecularProtozoan ProteinsRecombinant ProteinsSequence AlignmentSerologic TestsTrypanosoma brucei bruceiAntibodies, MonoclonalAntibodies, ProtozoanAntigens, ProtozoanCalcium-Binding Proteinsflagellar calcium-binding protein, Trypanosoma cruziProtozoan ProteinsRecombinant Proteins

Identifiers

PMID27055052
PMCPMC4824491
OpenAlexW2334792964

What OpenQuestion holds

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LicenceCC BY
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Registered trials

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.