The effect of environment on interferon-gamma production in neonatal foals

While interferon-gamma (IFNγ) plays an important role in protection against viral and intracellular bacterial infections, its production in neonates is deficient. Exposure to environmental antigens can promote the maturation of the immune system of neonatal humans and mice. We hypothesize that exposure to high level of microbial components would increase the production of IFNγ in neonatal foals. To test this hypothesis, one group of foals was placed into stalls three times a week for 8 weeks. A second group of foals remained on pasture. Air samples were collected from the barn and pasture for microbial culture. There were more bacteria and fungi in the air samples collected from the barn compared with those from the pasture. Bronchoalveolar lavage (BAL) cells and peripheral blood mononuclear cells (PBMC) were collected from both groups of foals at various times to assess IFNγ production. The frequency of IFNγ+ lymphocytes in BAL cells and PBMC was higher for foals kept in the stalls.