A DNA fragment of Leptospira interrogans encodes a protein which shares epitopes with equine cornea.

This study investigates the relationship between a protein from the bacterium Leptospira interrogans and a specific clinical disorder in horses known as recurrent uveitis. The research found that a particular DNA fragment from the bacterium encodes a protein which shares properties with proteins found in the horse’s cornea, potentially explaining why horses infected with the bacteria develop eye problems.

Background

• The research addresses the problem of recurrent uveitis in horses, which can result from an infection by the bacterium Leptospira interrogans.
• Previous studies have indicated a relationship between this bacterium and the equine cornea, potentially linking the bacterial infection and the eye disorder.

Methodology

• In order to further investigate this relationship, the researchers cloned a DNA fragment from a L. interrogans bacteria strain.
• The cloned DNA was placed under the control of a lacZ promoter, meaning the DNA would only be expressed in presence of Isopropyl β-D-1-thiogalactopyranoside (IPTG), a molecular biology reagent.
• This was accomplished using a technique in genomic library wherein a DNA fragment is isolated by expression using a polyclonal serum aimed against specific proteins.

Results

• The researchers found that the cloned DNA fragment encodes a protein of L. interrogans which reacts with the proteins found in the horse’s cornea.
• The protein metered 90 kilodaltons (kDa), which is a unit of measurement in molecular biology, and it strongly reacted with a protein found in the horse’s cornea that measures 66 kDa.
• The antibodies produced against this leptospiral protein can also recognise a protein from the equine cornea.

Conclusion

• This discovery suggests that the immune response of the horse to the 90 kDa protein may be involved in the development of equine uveitis.
• This understanding can provide better insights into the pathogenesis of equine uveitis and potentially guide the development of treatments or preventive measures for the disease.