Comparative evaluation of recombinant HSP70 (N & C-terminal) fragments in the detection of equine trypanosomosis.

The research explores the significance of recombinant heat shock protein 70 (HSP70) fragments in the detection of Trypanosomosis in horses. The study concluded that these recombinant fragments were more effective in detecting the presence of antibodies in infected ponies compared to traditional methods using whole cell lysate antigen.

Overview and Background

• Trypanosomosis, also known as Surra, is a disease caused by the extracellular parasite Trypanosoma evansi.
• It affects a range of hosts including domestic animals and has significant economic implications.
• Historically, detection of the disease has been based on identifying antibodies using a method known as ELISA that uses a whole cell lysate (WCL) antigen.
• However, this method has several drawbacks, including the persistence of antibodies after successful treatment of the disease and the ethical issue of requiring mice for in vivo maintenance of the parasite for antigen preparation.

Research Methodology and Results

• The research aimed to evaluate the production of recombinant heat shock protein 70 (HSP70) for antibody detection in experimentally infected ponies.
• The analysis of the amino acid sequence of HSP70 indicated significant differences in the level of conservation between the N-terminal and C-terminal regions of the protein.
• Four different regions of the HSP70 protein were cloned and expressed. HSP-1 and HSP-2, which included the N- and C- terminal regions, were truncated while HSP-3 and HSP-4 were complete C-terminal proteins.
• These recombinant fragments were tested with serum samples from experimentally infected ponies, with antibodies detectable from the 10th day post-infection until the experiment’s conclusion.
• Compared to the WCL antigen method, the recombinant fragments showed a steep drop in antibody detection following successful treatment of infected ponies. The antibodies persisted for more than a year with the WCL antigen test.

Conclusion and Implications

• The sensitivity and specificity of all HSP70 fragments were also estimated from field serum samples with reference to the WCL antigen ELISA.
• HSP-1, the N-terminal region, showed minimum sensitivity among all the recombinant fragments.
• Among the C-terminal fragments, HSP-2 showed the maximum sensitivity, while HSP-4 showed the least.
• Specificity increased for recombinant fragments from the N-terminal to the C-terminal region, with the HSP-4 fragment showing maximum specificity.
• These results suggest that the use of recombinant HSP70 fragments for antibody detection could improve the accuracy and speed of Surra diagnosis in horses, thereby reducing its economic impact and enhancing animal welfare.