AIMTo investigate effects of hsBAFF synthesized in Escherichia coli on spleen B lymphocyte immune response and its intracellular free Ca2+ ([Ca2]i]) signaling in mice.

METHODSTwenty ICR mice, half males-half females, were chosen and randomly divided into a normal control group (n=10) and a hsBAFF treatment group (n-10). The mice in hsBAFF treatment group were given abdominal cavity injection of hsBAFF solution which was diluted with phosphate buffered saline (PBS) at dosage of 0.1 mg/kg body weight once each day for over eight days. The mice in control group were received abdominal injection of PBS at the same dose and frequency. Spleen B lymphocyte proliferation and its immune response to LPS stimulation in mice were evaluated using an MTT assay, and change of spleen B lymphocyte [Ca2+]i was assayed under a laser scanning confocal microscope.

RESULTSB lymphocyte proliferation and its immune response to LPS stimulation were significantly higher in hsBAFF-treated mice than in control mice (P < 0.05). The B lymphocyte [Ca2+]i fluorescence intensity in hsBAFF-treated mice maintained at a relatively high level fluctuation, and its average intensity was significantly higher to that of control mice (P < 0.01), but change rate of the intensity was lower compared to that of control group.

CONCLUSIONhsBAFF synthesized in Escherichia coli can enhance immune function in the body by increasing B lymphocyte proliferation and its immune response. hsBAFF-activated B lymphocyte function may be associated with increasing B lymphocytes [Ca2+]i.