Monoclonal equine IgM and IgG immunoglobulins

Area of Science:

• Immunology
• Biotechnology
• Veterinary Science

Background:

• Equine immunoglobulins (Igs) are crucial for horse immunity but lack standardized monoclonal reference antibodies.
• Previous research has not produced monoclonal antibodies for all equine Ig isotypes, hindering detailed immunological studies.

Purpose of the Study:

• To generate monoclonal reference equine immunoglobulins (Igs) for defining equine Ig subclasses.
• To produce the first-ever monoclonal equine immunoglobulin M (IgM) and characterize equine immunoglobulin G (IgG) subclasses.

Main Methods:

• Equine peripheral blood mononuclear cells were fused with the X63-Ag8.653 murine myeloma cell line to create equi-murine heterohybridomas.
• Successful heterohybridoma lines expressing equine Ig for over 3 months were selected and characterized.
• Monoclonal antibodies were analyzed using sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) to determine molecular weight and identify heavy and light chain types.

Main Results:

• Twenty-nine equine Ig-producing heterohybridomas were generated, with ten expressing Ig for over 3 months.
• One heterohybridoma line produced monoclonal equine IgM, a previously unavailable isotype.
• Four lines secreted equine IgG of two distinct heavy chain types, and five lines expressed equine Ig light chains. Cloning yielded a sixth light chain variant.
• SDS-PAGE analysis identified five groups of gamma-chains and four groups of Ig light chains among the monoclonal IgGs.

Conclusions:

• The successful generation of monoclonal equine IgM and IgG antibodies provides essential reference standards for equine immunology.
• Characterization of equine IgG heavy and light chains advances the understanding of equine immunoglobulin diversity.
• These novel monoclonal antibodies will facilitate more precise diagnostic and research applications in equine health.