Analysis of the peanut agglutinin-binding site as a differentiation marker of normal and malignant human lymphoid cells.

The lectin peanut agglutinin (PNA), which interacts specifically with D-galactosyl residues, was studied for its binding to human normal and malignant lymphoid cells at various stages of differentiation. As previously reported, PNA binds to thymocytes; however, it does not interact with the prothymocytes which precede the cortical thymocyte differentiation stage. No mature peripheral cells in any of the lymphoid organs bind PNA. In contrast to the normal T differentiation pathway, the expression of the PNA-binding site does not seem to coincide with that of T cell characteristics in the various malignant lymphoid cells studied. We therefore conclude that more information is needed about the nature of the PNA-binding site before it can be used as a differentiation marker in malignant lymphoid cells.