Transgenerational effects enhance specific immune response in a wild passerine

Area of Science:

• Ecology and Evolutionary Biology
• Immunology
• Animal Behavior

Background:

• Maternal effects significantly influence offspring phenotype, but their impact on immunity is not fully understood.
• Vertebrate mothers transfer compounds to embryos, potentially modulating immune system development and function.
• The specific mechanisms by which maternal factors prime offspring immunity require further investigation.

Purpose of the Study:

• To investigate the impact of maternal vaccination on offspring immunity in wild house sparrows (Passer domesticus).
• To determine if maternally derived antibodies directly transfer or prime offspring immune responses.
• To assess the relationship between maternal antibody levels and offspring immune capabilities.

Main Methods:

• Wild house sparrows were vaccinated with Newcastle disease virus (NDV) vaccine during their first brood.
• Immune responses (NDV-specific and PHA test) were measured in 11-day-old chicks from subsequent broods.
• Blood samples were analyzed for antibody concentrations, carotenoids, and antioxidant capacity.

Main Results:

• Chicks from vaccinated mothers showed a stronger specific immune response to NDV, correlated with maternal antibody levels.
• Offspring carotenoid levels and antioxidant capacity were negatively related to maternal NDV antibody concentration.
• No direct detection of NDV antibodies in chicks suggested a priming effect rather than passive transfer.

Conclusions:

• Maternally transmitted antibodies in house sparrows are short-lived and enhance offspring's specific immunity through a priming mechanism.
• This maternal priming effect boosts pre-fledging immunity against specific pathogens encountered by the mother.
• Other immune components, like inflammatory responses, may not be directly modulated by these maternally derived antibodies.