Analysis of monoclonal antibodies reactive with meconium- and amniotic fluid-derived mucin

The present study was undertaken to determine whether monoclonal antibodies (moABs TKH-2, MA54, MA61, B72.3, and CC49) directed toward O-linked mucin-type glycoprotein detect the NeuAc alpha 2-6GalNAc (sialyl Tn) epitope in meconium- and amniotic fluid-derived mucin. Fetal colonic mucosal cells express the sialyl Tn antigen, particularly in goblet cell mucin. The reactivities of these moABs with a perchloric acid extract of meconium (meconium extract) and different native and neuraminidase treated glycoproteins were examined by solid-phase enzyme-linked immunosorbent assay (ELISA). All the moABs react with the meconium supernatant and meconium extract. The reactivities of TKH-2, MA54, and MA61 are neuraminidase sensitive, and the reactivity of TKH-2 with meconium extract was specifically inhibited by ovine submaxillary mucin (OSM). A NeuAc alpha 2-6GalNAc epitope is the characteristic component in meconium. Mucin released from the fetal respiratory tract could, in part, provide an alternative source in the amniotic fluid. TKH-2 is the most sensitive antibody directed to sialyl Tn antigen in meconium supernatant. The likelihood of TKH-2 serving as the basis for a sensitive assay to detect sialyl Tn in meconium- and amniotic fluid-derived mucin is provided.