Heterogeneity of human natural killer cells with respect to lectin-binding ability

The binding ability of peanut agglutinin (PNA), lentil agglutinin (LEN), soybean agglutinin (SBA), wheat germ agglutinin (WGA), and asparagus pea agglutinin (ASP) to human natural killer (NK) cells with the use of the double-marker immunofluorescence technique was studied. For identification of NK cells, VEP 13 (DC 16) monoclonal antibody was used. The receptor for PNA lectin was shown exclusively after neuraminidase treatment of cells, and VEP 13 antigen was neuraminidase resistant. The majority of VEP 13+ cells showed coexpression of lectin receptors for PNA, LEN, and WGA. Our results suggested that VEP 13 antigen and PNA receptor are two distinct membrane structures, whereas there is some competitive binding between LEN as well as WGA lectin and VEP 13 antibody. In double-marker experiments using PNA and LEN lectin, the small fraction of VEP 13+ cells lacking receptors for these lectins was found. In spite of neuraminidase treatment of the cells, no binding of SBA and ASP was shown. These results indicated apparent heterogeneity of NK cells with respect to lectin receptor expression. WGA lectin, which bound to all VEP 13+ cells, could probably be useful for isolation of NK cells.