Analysis of the Cross-Reactivity of Various 56 kDa Recombinant Protein Antigens with Serum Samples Collected after Orientia tsutsugamushi Infection by ELISA

Chao, Chien‐Chung; Huber, Erin; Porter, Terrisita B.; Zhang, Zhiwen; Ching, Wei‐Mei

doi:10.4269/ajtmh.2011.10-0545

Cited by 24 publications

(34 citation statements)

References 34 publications

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“…The sequence of the variable domain 1 was replaced by that in TA763 with modifications as described. 11 The DNA was synthesized by Bioclone (San Diego, CA) and cloned into a pET29a vector (Novagen, Madison, WI) with built-in Nde I and Xho I restriction sites. The synthesized DNA sequences were confirmed.…”

Section: Methodsmentioning

confidence: 99%

Development of New, Broadly Reactive, Rapid IgG and IgM Lateral Flow Assays for Diagnosis of Scrub Typhus

Silpasakorn¹,

Srisamut²,

Ekpo³

et al. 2012

The American Society of Tropical Medicine and Hygiene

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Abstract. We evaluated the diagnostic accuracy of two broadly reactive rapid immunochromatographic tests (ICTs) for detection of IgM and IgG against Orientia tsutsugamushi by using archived acute-phase serum samples from 102 patients with laboratory-confirmed scrub typhus, and from 62 archived serum samples from patients with other causes of fever as a negative control. These ICTs were constructed by using a mixture of recombinant proteins: 1) C1, a chimeric protein containing epitopes of the 56-kD antigen from Karp and TA763 strains; 2) Ktr56; and 3) Gmr56. Sensitivities of the ICTs for detection of IgM and IgG were 90.2% (95% confidence interval [CI] = 84.4-96.0%) and 86.3% (95% CI = 80.9-93.8%), respectively. Specificities were 85.5% (95% CI = 73.9-92.2%) and 96.8% (95% CI = 90.3-100%), respectively. Both assays were more sensitive and specific than the standard immune immunofluorescence assay for the early diagnosis of scrub typhus.

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Section: Methodsmentioning

confidence: 99%

Development of New, Broadly Reactive, Rapid IgG and IgM Lateral Flow Assays for Diagnosis of Scrub Typhus

Silpasakorn¹,

Srisamut²,

Ekpo³

et al. 2012

The American Society of Tropical Medicine and Hygiene

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“…31 The serodiagnosis of scrub typhus depends on the less sensitive Weil-Felix test and immunofluorescence test, which are expensive and require expertise. 33,34 There is some evidence that the 47-kDa protein of O. tsutsugamushi may have the potential to initiate autoimmune response because of the cross-reaction with human HtrA protein due to the presence of homologous amino acid sequences. 32 The 56-kDa antigen was reported to show high antigenic variation and the antibodies are not cross-reactive.…”

Section: Discussionmentioning

confidence: 99%

Identification of B‐ and T‐cell epitopes on HtrA protein of Orientia tsutsugamushi

Sankar

Saravanan

Rajendiran

et al. 2018

J of Cellular Biochemistry

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Orientia tsutsugamushi, a cause of scrub typhus is emerging as an important pathogen in several parts of the tropics. The control of this infection relies on rapid diagnosis, specific treatment, and prevention through vector control. Development of a vaccine for human use would be very important as a public health measure. Antibody and T‐cell response have been found to be important in the protection against scrub typhus. This study was undertaken to predict the peptide vaccine that elicits both B‐ and T‐cell immunity. The outer‐membrane protein, 47‐kDa high‐temperature requirement A was used as the target protein for the identification of protective antigen(s). Using BepiPred2 program, the potential B‐cell epitope PNSSWGRYGLKMGLR with high conservation among O. tsutsugamushi and the maximum surface exposed residues was identified. Using IEDB, NetMHCpan, and NetCTL programs, T‐cell epitopes MLNELTPEL and VTNGIISSK were identified. These peptides were found to have promiscuous class‐I major histocompatibility complex (MHC) binding affinity to MHC supertypes and high proteasomal cleavage, transporter associated with antigen processing prediction, and antigenicity scores. In the I‐TASSER generated model, the C‐score was −0.69 and the estimated TM‐score was 0.63 ± 0.14. The location of the epitope in the 3D model was external. Therefore, an antibody to this outer‐membrane protein epitope could opsonize the bacterium for clearance by the reticuloendothelial system. The T‐cell epitopes would generate T‐helper function. The B‐cell epitope(s) identified could be evaluated as antigen(s) in immunodiagnostic assays. This cocktail of three peptides would elicit both B‐ and T‐cell immune response with a suitable adjuvant and serve as a vaccine candidate.

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“…These protein aggregates were once considered to be waste products, but recent discoveries have revealed that inclusion bodies actually contain biologically active polypeptides [13]. The inclusion bodies purified in this study were denatured using the Bug Buster protein extraction kit, and sequential reduction in urea concentration was used to refold the denatured protein [14]. …”

Section: Discussionmentioning

confidence: 99%

Cloning, expression, and immunocharacterization of surface protein containing an altered thrombospondin repeat domain (SPATR) from Plasmodium knowlesi

Palaeya

Lau

Mahmud

et al. 2013

Malar J

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BackgroundPlasmodium knowlesi is the fifth species identified to cause malaria in humans and is often misdiagnosed as Plasmodium malariae due to morphological similarities. The development of an inexpensive, serological detection method utilizing antibodies specific to P. knowlesi would be a valuable tool for diagnosis. However, the identification of specific antigens for these parasites remains a major challenge for generating such assays. In this study, surface protein containing an altered thrombospondin repeat domain (SPATR) was selected as a potentially specific antigen from P. knowlesi. Its multistage expression by sporozoites, asexual erythrocytic forms and gametocytes, along with its possible role in liver cell invasion, suggests that SPATR could be used as a biomarker for diagnosis of P. knowlesi.MethodsThe spatr gene from P. knowlesi was codon optimized and cloned (pkhspatr). Recombinant pkHSPATR protein was expressed, purified, and evaluated for its sensitivity and specificity in immunoblot and ELISA-based assays for detecting P. knowlesi infection.ResultsThe recombinant pkHSPATR protein allows sensitive detection of human P. knowlesi infection in serum samples by immunoblot and ELISA.ConclusionsWith further research, recombinant pkHSPATR protein could be exploited as a marker for detection of P. knowlesi infection in humans. Therefore, this finding should contribute to the development of immunodiagnostic assays for the species-specific detection of malaria.

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Analysis of the Cross-Reactivity of Various 56 kDa Recombinant Protein Antigens with Serum Samples Collected after Orientia tsutsugamushi Infection by ELISA

Cited by 24 publications

References 34 publications

Development of New, Broadly Reactive, Rapid IgG and IgM Lateral Flow Assays for Diagnosis of Scrub Typhus

Development of New, Broadly Reactive, Rapid IgG and IgM Lateral Flow Assays for Diagnosis of Scrub Typhus

Identification of B‐ and T‐cell epitopes on HtrA protein of Orientia tsutsugamushi

Cloning, expression, and immunocharacterization of surface protein containing an altered thrombospondin repeat domain (SPATR) from Plasmodium knowlesi

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