Intrauterine inflammation is a common antecedent of preterm birth and can alter the development of the fetal thymus, the site of development, and maturation of T lymphocytes. The effects of intrauterine inflammation on specific thymic T lymphocyte populations are largely unknown. We hypothesized that intrauterine inflammation would alter fetal thymic T cell populations. Immunohistochemistry was used to quantitate the relative proportions of thymic cortical and medullary cell populations in fetal sheep 7 days after intra-amniotic lipopolysaccharide (LPS) injection. The proportions of CD8(+)and MHC II(+) cells in the fetal thymus were reduced in response to LPS. The ratio of CD4:CD8 cells was increased by LPS exposure. No changes were observed in the percentage of CD4(+), gammadelta(WC1)(+), CD45R(+)B cells, or CD44(+) cells. These studies indicate that intrauterine inflammation impacts thymic composition of CD8 T cells and the development and/or activation of CD4 T cells in the fetal thymus.
Melville, J., Bischof, R., Meeusen, E. N. T., Westover, A. J., & Moss, T. J. M. (2012). Changes in fetal thymic immune cell populations in a sheep model of intrauterine inflammation. Reproductive Sciences, 19(7), 740 - 747. https://doi.org/10.1177/1933719111432873