Figure 3

Protein level of endogenous CD72Δex8 is increased in peripheral blood B cells in individuals with CD72*2. A: Levels of cell surface expression of CD72 in individuals with each CD72 genotype. Peripheral blood B cells were isolated from 9 healthy donors (three CD72*1/1, four CD72*1/2, and two CD72*2/2). Cell surface expression was analyzed by flow cytometry using a FACSCalibur. B and C: Expression of CD72Δex8 in B cells from individuals of each CD72 genotype and WEHI-CD72Δex8 transfectants. Peripheral blood B cells were isolated from 7 healthy donors (four CD72*1/1, two CD72*1/2 and one CD72*2/2) by autoMACS. Cells were lysed, and total cell lysates were subjected to Western blot analysis using antibody specific to CD72Δex8 (B). The same blots were reprobed with anti-β-tubulin Ab to ensure equal loading. Levels of expression of CD72Δex8 were standardized to that of β-tubulin. Data are shown in dot plots (C). CD72Δex8 levels in peripheral blood B cells correlate to the number of CD72*2 (P < 0.05; Mann–Whitney U test). Values are the mean ± SE. Representative data from three experiments are shown.