Responses of lymphocytes from human colostrum or milk to influenza antigens.

Paired samples of peripheral blood and colostrum or milk were obtained from women 1 to 6 days after delivery. After Ficoll-Hypaque centrifugation, peripheral blood lymphocytes (PBL) and colostrum or milk lymphocytes (COL) were examined for surface membrane characteristics and in vitro proliferative reactivity. As determined by sheep red blood cell rosetting and by immunoglobulin-coated beads, PBL showed an average of 54% T and 12% B lymphocytes, whereas COL showed 33% T and 22% B rosettes, respectively. Paired samples of PBL and COL were used for lymphocyte transformation with three distinct strains of influenza virus: A/USSR, A/Victoria, and B/Hong Kong. Of COL from nine subjects tested against all three strains of influenza virus, five samples (56%) gave positive responses to at least one. These studies indicate that COL contain cells responsive in vitro to several influenza antigens. Such sensitized cells may provide a mechanism for the transfer of antigen responsiveness and protection from the mother to the neonate.