Exploring the sheep (Ovis aries) immunoglobulin repertoire by next generation sequencing

Area of Science:

• Immunology
• Genomics
• Veterinary Science

Background:

• Sheep are crucial for therapeutic antibody production, but their immune repertoires remain poorly understood.
• Adaptive immune responses and antibody generation processes in sheep require further investigation.

Purpose of the Study:

• To comprehensively analyze immunoglobulin heavy (IGH) and light (IGK, IGL) chain repertoires in healthy sheep using next-generation sequencing (NGS).
• To establish a foundational understanding of ovine adaptive immunity for improved therapeutic antibody development.

Main Methods:

• Employed next-generation sequencing (NGS) to analyze antibody repertoires in four healthy sheep.
• Sequenced immunoglobulin heavy (IGH), kappa (IGK), and lambda (IGL) chain loci to identify unique CDR3 sequences and gene usage patterns.

Main Results:

• Obtained over 90% complete antibody sequences with extensive unique CDR3 reads for IGH, IGK, and IGL loci.
• Observed biased usage of germline V, D, and J genes in IGH and IGK loci, contrasting with non-biased usage in IGL loci.
• Demonstrated significant diversity in CDR3 sequences through clustering and convergent recombination analysis.

Conclusions:

• The study provides the first comprehensive NGS-based analysis of ovine antibody repertoires.
• Findings reveal specific patterns of gene usage and diversity, crucial for understanding sheep adaptive immunity.
• This research lays the groundwork for future studies on ovine immune responses in health and disease and enhances ovine-derived therapeutic antibody development.