Primary in vitro antibody response in human cord blood lymphocytes.

Human cord blood lymphocytes were stimulated with trinitrophenyl--polyacrylamide beads (TNP--PAA) in order to induce a primary IgM anti-TNP response. With few exceptions, no anti-TPN response was obtained, whereas peripheral blood lymphomonocytic cells (PBL) from 18-mth-old children were able to respond to TNP-PAA. The addition of lipopolysaccharide (LPS) or of mitomycin-treated adult PBL to cultures of cord blood lymphocytes significantly enhanced their anti-TNP response, thus showing that functional anti-TNP B cell precursors are present in the human neonate.