THE EXPRESSION OF LY-5 (B220) IN B CELLS OF MOUSE DURING ACTIVATION
CONG YING-ZI, YU SHI-GUANG (Department of Biology, Shandong University, Jinan 250100)
The expression of Ly-5 (B220) in splenic B cell of mouse and the change of Ly-5 (B220) during B cell activation were studied by using FACS technique. The results showed that the splenic B cell form two populations. The smaller splenic B cell with high-density has the phenotype of Ly-5hi, and the larger population with low-density is of Ly-5low phenotype. Activation of resting B cells by LPS and anti-IgM induces differences in the level of Ly-5 expression. Stimulation of resting B cell of Ly-5hi. phenotype, but the latter remains high as the anti-IgM stimulation is used alone for. Additional stimulation of IL-6 following anti-IgM stimulation can decrease the level of Ly-5 expression. However, IL-1, IL-2, or IL-4, whether alone or in various combinations, can not induce the loss of Ly-5. Taking those together, we can conclude that the expression of Ly-5 goes down following B cell activation and Ly-5low may serve as an activation marker of B cell activation.