Dexamethasone effects on survival, differentiation, and proliferation of peritoneal (or B-1 cells) and splenic B cells

Choi, Joo Hyuk; Jeung, In Cheal; Park, Dong Choon

Abstract

OBJECTIVE
Although the characteristic feature and function of peritoneal B (B-1) cells are very different from splenic B (B-2) cells, peritoneal B cell study is not known well. The aim of this study is to investigate the effects of dexamethasone on peritoneal (or B-1 cells) and splenic B cells (or B-2 cells).
METHODS
The synthetic corticosteroid, dexamethasome, was injected to BALBc mice intraperitoneally or subcutaneously at 4-5 pm for 7 days. Expression level of B cell surface marker analyzed by flow cytometry. The purified peritoneal B cell and splenic B cells were obtained and cell survival rate was analysed by flow cytometry. Isolated B cells were cultured in medium with different concentration of dexamaethasone. During the culture of these cells, immunoglobulin secreted into the culture supernatants was evaluated by enzyme-linked immunosorbent assay. Entering of S phase was measured by proliferative assay.
RESULTS
Subcutaneous injection of high dose of Dexamethasone for 7 days did not affect cell surface markers of peritoneal and splenic B cells. However, all cell surface markers of peritoneal B cell after the treatment of dexamethasone are reduced by daily intraperitoneal injection of dexamethasone for 2 days. The survival rate of peritoneal and splenic B cell decrease with increasing concentration of dexamethasone. Proliferation of peritoneal B cells was less affected by dexamethasone than that of splenic B cells (p<0.05).
CONCLUSIONS
Dexamethasone induced apoptosis in both peritoneal and splenic B cells. Proliferation and differentiation of splenic B cells were affected by dexamethasone, but peritoneal B cells are less sensitive to dexamethasone.