Eryptotic Phenotype in Chronic Myeloid Leukemia: Contribution of Neutrophilic Cathepsin G

Figure 2

Detection of Antigens on erythrocyte membrane which are recognized by serum IgG. (a) autographs of western blots of membranes of erythrocytes from CML patients designated C, and controls (N) stained with IgG separated from sera of the respective individual have been shown. A 43 kDa fragment is stained in normal and a larger number of CML while fragments at 55 and 26 kDa are stained mainly in CML erythrocytes. The antigens are identified as fragment of band 3 (43 kDa), myeloperoxidase (55 kDa), and cathepsin G (26 kDa) by mass spectrometry (details in Table 1). (b) The identity of cathepsin G was validated by immunostaining of western blots of erythrocyte membranes with cathepsin G-specific antibody. CML samples show higher expression of cathepsin G. (c) Immunostaining of blotted proteins from cytosol of normal and CML erythrocytes with PKC βII antibody shows a low-intensity band in both. PKC βII is expressed in neutrophils but not in erythrocytes. Insignificant detection of PKC βII in both normal and CML samples rules out the detection of cathepsin G due to contamination of neutrophils in the erythrocyte preparation. Rat brain lysate is the positive control.