Monoclonal antibody B2, a marker of neuroendocrine sympathoadrenal precursors, recognizes the Luke (LKE) antigen.

BACKGROUND Blood group antigens are physiologically important differentiation markers in embryogenesis and development. Monoclonal antibody (MoAb) B2 recognizes a transient antigen expressed on late sympathoadrenal neuroendocrine precursors and early sympathetic neuroblasts. It has been suggested that MoAb B2 may recognize a globo-series glycosphingolipid (GSL) related to the P blood group family. STUDY DESIGN AND METHODS MoAb B2 and two anti-LKE MoAbs, MC813-70 and RM1, were screened against a panel of GSL standards and isolated red blood cell (RBC) GSLs by high-performance thin layer chromatography (HPTLC) immunostaining. The ability of all three MoAbs to bind intact RBCs and two LKE+ renal cell carcinoma cell lines (A498, ACHN) were examined by flow cytometry and hemagglutination. RESULTS MoAbs B2, MC813-70, and RM1 all specifically recognized monosialogalactosylgloboside (MSGG) on HPTLC immunostaining. Only MoAb MC813-70 bound intact RBC by flow cytometry and hemagglutination. Differential staining was observed between the three antibodies and two renal cell carcinoma cell lines. CONCLUSION MoAb B2 recognizes MSGG or LKE antigen, suggesting that LKE may play a role in neuroendocrine differentiation from neural crest cells. Although MoAb B2 is not suitable for RBC phenotyping, it may be a useful immunologic reagent for the identification of human embryonic stem cells and renal cell and embryonic carcinoma.