Association of beta-2-microglobulin and HL-A in the cell membrane. A general property in human cells?

To study whether the recently reported close association of beta-2-microglobulin and HL-A determinants is restricted to lymphocyte membranes or might be a more general property, experiments were performed where normal and malignant human cells were tested for coaggregation-capping of the two determinants. The normal cells were fibroblasts and the epithelial cells were from skin. The turmor cell lines were HeLa clone S3 carcinoma cells and National Collection of Type Cultures strain 3075, which is a line of malignant human skin cells. The cells were double-stained with fluorescein-labelled conjugates to demonstrate the reaction of anti-HL-A and anti-beta-2-microglobulin with the respective cell membrane components. Aggregation and capping of the HL-A and beta-2-microglobulin determinants in the cell membrane were always observed after incubation at 37 C for 30 min. The red and green fluorescence were always superimposed when anti-beta-2-microglobulin was used in the first (aggregating) incubation step. This demonstrates that the HL-A and beta-2-microglobulin determinants are also associated in the cell membrane of cells other than lymphocytes.