Antibody repertoire development in swine

Area of Science:

• Immunology
• Comparative immunology
• Mammalian immune systems

Background:

• Swine express diverse antibody isotypes (IgM, IgD, IgG, IgE, IgA) with numerous IgG subclasses.
• Their immunoglobulin heavy (V(H)) and light chain gene usage presents a unique profile compared to other mammals.
• Early B cell development in swine exhibits distinct features, including high in-frame VDJ rearrangements and N-region additions.

Purpose of the Study:

• To delineate the unique features of the swine adaptive immune system.
• To highlight the swine as a model for fetal-neonatal immunology.
• To compare swine immune system development with other mammals.

Main Methods:

• Analysis of antibody gene expression (V(H), D(H), J(H), V(kappa), J(kappa), V(lambda)).
• Examination of B cell development stages and rearrangements.
• Comparative analysis with immune systems of other species (mice, humans, rabbits, chickens, camelids, cattle, sheep).

Main Results:

• Swine utilize a restricted set of V(H) genes (primarily V(H)3 family) and D(H)/J(H) segments, emphasizing junctional diversity.
• Light chain usage in swine resembles humans, differing from rodents and other ungulates.
• Unique B cell development observed in swine thymus and yolk sac; ileal Peyer's patches suggest antigen-independent diversification.
• Swine neonates lack passive immunity, making them a model for studying immune development and responses to gut colonization and pathogens.

Conclusions:

• The swine immune system exhibits significant evolutionary diversification, challenging direct extrapolation of findings from other mammalian models.
• Swine offer a valuable model for investigating fetal-neonatal immunity, gut microbiome influence, and pathogen interactions.
• Understanding swine immunology is crucial for accurate interpretation of research findings and for developing targeted interventions.