[Neutralizing single-chain antibodies against the tick-borne encephalitis virus]

Area of Science:

• Immunology
• Virology
• Molecular Biology

Background:

• Tick-borne encephalitis (TBE) virus poses a significant public health threat.
• Development of effective antiviral therapies against TBE virus is crucial.
• Monoclonal antibodies offer a promising avenue for targeted antiviral interventions.

Purpose of the Study:

• To construct a recombinant plasmid for expressing a single-chain antibody against the TBE virus.
• To characterize the binding affinity and functional activity of the developed single-chain antibody (sc13D6).

Main Methods:

• Construction of a pSC13D6 plasmid using cDNA fragments encoding variable domains of the MKA 13D6 antibody.
• Expression of the sc13D6 single-chain antibody in Escherichia coli.
• Binding assays to evaluate antibody interaction with TBE virus and recombinant E protein.
• Affinity constant determination using equilibrium and surface-based methods.
• In vitro assessment of TBE virus neutralization by sc13D6.

Main Results:

• Successful expression of sc13D6 single-chain antibody against TBE virus in E. coli.
• Demonstrated binding of sc13D6 to TBE virus (strain 205) and recombinant TBE virus E protein.
• High affinity constants for sc13D6: (3.0 ± 0.2) x 10^7 M⁻¹ (equilibrium) and (2.8 ± 0.3) x 10^7 M⁻¹ (surface).
• Significant inhibition of TBE virus infection potency by sc13D6, with an IC50 value of 16.7 µg/ml.

Conclusions:

• The sc13D6 single-chain antibody effectively targets the TBE virus.
• The developed antibody exhibits high binding affinity and potent virus-neutralizing activity.
• sc13D6 represents a potential candidate for TBE virus therapeutic strategies.