Role of the erythrocyte protein Band 3 in autoimmune hemolytic anemia associated to chronic lymphocytic leucemia

MORANDE PABLO; ZANETTI SAMANTA; BORGE MERCEDES; NANNINI PAULA; BEZARES FERNANDO; OPPEZZO PABLO; GAMBERALE ROMINA; GIORDANO MIRTA

Buenos Aires

Congreso; First French-Argentine Immunology Congress, 2010; 2010

Vol.1No. 3:4doi: 10:3823/413p23Chronic lymphocytic leukemia (CLL) is the most common cause of autoimmune emolytic anemia (AHA). We have previously shown that neoplastic B cells are able to bind the erythrocyte protein Band 3 (B3) through its N-terminal domain (B3N), an ability that could allow the neoplastic clone to trigger the autoimmune process. The aims of the present work were: 1) to identify molecules in the cell membrane of leukemic B cells as candidates for being B3N binding site and 2) to investigate the process of binding and endocytosis of erythrocyte-derived vesicles to leukemic B cells. In order to accomplish our first objective, weremoved non-integral membrane proteins from DAUDI cells (a human B cell line that we have previously reported to bind B3N) by acidic elution using potasium phosphate 0.1M, sodium citrate 0.05M buffer, pH=2.5. By flow cytometric analysis, we found that this treatment decreased the binding of B3N (50 ug/ml) to cells (MFI control cells: 160±8, MFI treated cells: 70±10, n=5, p