mRNA from porcine colostral and milk cells coding for specific antibodies in response to orally administered Escherichia coli strains

The effect of feeding live $\text{Escherichia coli}$ bacteria to sows on the lymphocyte populations in colostrum and milk was studied by $\text{in ovo}$ translation of the mRNA of these cells (Kortbeek-Jacobs and van der Donk, 1978). Four $\text{E. coli}$ strains were tested: one wild type K88 producing strain, two conjugated K12 strains producing K88 antigen and one wild type K12 strain. Only after feeding the wild type K88 bacteria, colostral lymphocytes contained mRNA coding for anti-K88 antibodies, predominantly of the IgA and IgM isotypes. Milk lymphocytes of the sows receiving one of the other strains were capable of producing more anti-K88 antibodies than the sows that were fed the wild type K88 strain. Antibodies were predominantly of the IgM class. The reactivity of the milk lymphocytes is ascribed to the strain with which the piglets were challenged. The results support the phenomenon of sensitized gut lymphocytes that home to the mammary gland.