Cloning and Expression of the Neonatal Rat Intestinal Fc Receptor, a Major Histocompatibility Complex Class I Antigen Homolog
This extract was created in the absence of an abstract.
Excerpt
Although the immune system of the late fetus is capable of antibody synthesis, it is normally sheltered from foreign antigens. Because a pregnant or nursing mammal is exposed to roughly the same antigenic environment as the newborn, a mother's immunological experience is directly relevant to the needs of her offspring. Maternal IgG is transmitted to fetal or neonatal mammals and provides humoral immunity during the first weeks of independent life. Humans are born with IgG that was transported across the placenta. In contrast, cattle are agammaglobulinemic at birth and receive IgG from colostrum. There is some prenatal transfer in mice and rats, by way of the uterine lumen and fetal yolk sac, but most IgG is obtained from colostrum and milk. Receptors for the Fc region of IgG (FcRn, neonatal) mediate its internalization at the apical surface of intestinal epithelial cells of the suckling rat. The pH in the gut...
