COMMON ANTIGENIC STRUCTURES OF HLA ANTIGENS .7. SELECTIVE COMBINATION BINDING OF (BETA)2-MICROGLOBULIN WITH HLA LARGE COMPONENT IN CULTURED HUMAN CELL LINES

  • 1 January 1977
    • journal article
    • research article
    • Vol. 32  (2) , 139-150
Abstract
The intracellular distribution of human .beta.2-microglobulin was examined in human cell lines (Burkitt lymphoma [B46M] cells B[bone marrow-derived]-lymphoid [RPMI 1788] cells and cervical carcinoma HeLa cells). Freshly harvested cells were mechanically disrupted and separated into the nuclear, cell-membrane and cell-sap fractions. Nearly 90% of the total .beta.2-microglobulin was recovered in the cell-membrane and cell-sap fractions. The cell-membrane fraction contained 75-88% of the .beta.2-microglobulin recovered. The rest was in the cell-sap fraction. Most (84-91%) of the .beta.2-microglobulin in the cell-membrane fraction was present combined with membrane components of about 38,000 daltons that carried the xenoantigenic activity characteristic of the HL-A large component. These membrane components did carry HL-A alloantigenic activity. No other membrane components were involved in binding .beta.2-microglobulin. The .beta.2-microglobulin in the cell-sap fraction was present in the unbound state. The membrane component which was combined with .beta.2-microglobulin appeared to be exclusively the HL-A large component and no large excess of .beta.2-microglobulin over the HL-A large component was found.