Browsing by Author "Eva Liebau"

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Brugia malayi and Wuchereria bancrofti: Gene comparison and recombinant expression of π-class related glutathione S-transferases
(Academic Press Inc., 2003) Sushma Rathaur; Peter Fischer; Marzena Domagalski; Rolf D. Walter; Eva Liebau
The nucleotide sequence for Brugia malayi and Wuchereria bancrofti GST have been submitted to EMBL, GenBank, and DDBJ Nucleotide Sequence Databases under Accession Nos. Y12788 and AY195867. © 2003 Elsevier Science (USA). All rights reserved.
Human immune response against filarial HSP70 and its role in the diagnosis of lymphatic filariasis
(John Wiley and Sons Inc, 2023) Faiyaz Ahmad; Eva Liebau; Sushma Rathaur
A sensitive and specific diagnostic kit is crucial for the detection of human lymphatic filariasis at the early stage of infection as the existing diagnostic tools are inefficient and expensive. In the present study, we have cloned and expressed Brugia malayi HSP70 (BmHSP70) protein and characterized it as a potential antigen for diagnosis of the asymptomatic microfilariae stage of Wuchereria. bancrofti infection using ELISA, western blot, and bioinformatics tools. The antigenic efficacy of BmHSP70 was also compared with ScHSP70. The BmHSP70 and ScHSP70 peptide showed highly antigenic in nature and they showed immunogenic cross-reactivity endemic normal (EN) < chronic (CH) < microfilaraemic (MF) in IgG, IgG1, and IgG4 ELISA. IgG4-specific immunoblotting of BmHSP70 with MF sera further explicated its stage-specific antigenic cross-reactivity. These antigens (ScHSP70 and BmHSP70) showed a positive immunogenic correlation with the number of MF in blood samples. Thus, proposing BmHSP70 as a potential immunodiagnostic antigen against lymphatic filariasis. A triplet of GGMP tetrapeptide specific to the filarial HSP70 was also identified which was absent in human HSP70. In terms of sensitivity and specificity of antigens, these results suggest that recombinant BmHSP70 is a good antigen and could be used to diagnose early-stage of microfilariae infection. © 2023 John Wiley & Sons Ltd.
Identification of major antigenic peptide of filarial glutathione-S-transferase
(2011) Marshleen Yadav; Eva Liebau; Chandana Haldar; Sushma Rathaur
In our earlier report, a 26kDa Setaria cervi glutathione-S-transferase showed significant protection (82%) in jirds infected with L3 larvae of Brugia malayi. In the present study we have identified the major antigenic epitopes in ScGST. Carboxypeptidase B has been used to digest the ScGST in to smaller fragments. The digested products were separated as four protein bands on SDS-PAGE. The smallest fragment of 6kDa (P4) from ScGST was identified as major antigenic epitope because of its significant reactivity with jird anti ScGST sera and human filarial sera in immunoblotting. The MALDI-LC/MS sequencing of ScGST P4 peptide (5KLTYFSIRGRGLAEPIRL20, 22KVPDDQQFLDDLISR36 and 47VFHFGQGPHHGPPR62) suggested that this protein band has a fragment of 5-62 residues long that matched with the N-terminal end of filarial GST. The antigenicity plot of ScGST was compared with BmGST model and both exhibited three immunogenic peaks within the first 60 residues towards N-terminal. In BmGST the N-terminal region was also detected with N-glycosylation signal peptide NAS adding to its high immunogenic property. Further, P4 showed strong reactivity with IgG1 and IL-4 response in endemic normal sera suggested its role in Th2 response which in turn is correlated with antibody dependent cell mediated cytotoxicity. Thus taking these results into account we propose 5-62 residues long N-terminal peptide of GST as a potential target for further vaccination studies against filarial infection. © 2010 Elsevier Ltd.
Identification of Setaria cervi heat shock protein70 by mass spectrometry and its evaluation as diagnostic marker for lymphatic filariasis
(2010) Saurabha Srivastava; Elesela Srikanth; Eva Liebau; Sushma Rathaur
Using mass spectrometry and immunological approaches, a heat shock protein70 associated with lymphatic filariasis (LF) has been identified from a bovine filarial parasite Setaria cervi. A heat shock protein was detected in different life stages of S. cervi when exposed to an elevated temperature of 44 °C. A combination of ATP-agarose column chromatography and electro-elution was used for its purification from adult female extract. On closer examination, it migrated as a single band at 68 kDa on 10% SDS-PAGE. Peptide sequences TTPSYVAFTDTER, DSGAIAGLNVLR, IINEPTAAAIAYGLDK, NALESYAFNMK and LLSDFFSGK were obtained through MALDI-LC/MS analysis. Confirmation of peptides was accomplished by MASCOT database which showed substantial sequence homology with S. digitata, Wuchereria bancrofti, and Caenorhabditis elegans. Multiple sequence alignment using Clustal W showed 98% identity with W. bancrofti and only 28% with human HSP70. Furthermore, the antigenicity plot has shown that the highly antigenic amino acid residues are constituted within the conserved peptides. These observations suggest a plausible biological connection of ScHSP70 with the disease and its strong immunogenic nature. ScHSP70 showed antigenic cross-reactivity with IgG class of antibody in different categories of filarial sera. However, when IgG subclasses were tested, IgG4 showed high specificity and sensitivity with asymptomatic microfilaraemic sera. © 2009.
Structural modeling and simulation studies of Brugia malayi glutathione-S-transferase with compounds exhibiting antifilarial activity: Implications in drug targeting and designing
(2010) Marshleen Yadav; Alka Singh; Sushma Rathaur; Eva Liebau
Since glutathione-S-transferase (GST) mediated xenobiotic detoxification is a crucial mechanism in nematodes survival, we aimed to conduct an in silico analysis of filarial GST in order to predict the possible interactions for antifilarials. Present report depicts the homology modeling approach applied in the construction of molecular structure of Brugia malayi GST (BmGST) followed by its docking simulation with available antifilarials such as diethylcarbamazine, albendazole, Butylated Hydroxyanisole (BHA) and substituted chalcones. A very low root mean square deviation (0.82 Å) from template structure and stereochemical quality of constructed BmGST model proposed it as a significant framework for further analysis. In docking studies antifilarials and chalcones exhibited demarcation in their binding affinity and modes. Amongst all the compounds studied, albendazole and methyl-substituted chalcone showed the lowest binding energy and occupied binding pocket near to substrate binding site of GST. The side chain of these compounds interplayed as a potential interaction site which targeted mainly hydrophilic residues of the BmGST. The structural information and binding site mapping of BmGST for different antifilarials obtained from this study could aid in screening and designing new antifilarials or selective inhibitors for chemotherapy against filariasis. © 2009 Elsevier Inc. All rights reserved.