Physiol. Res. 55: 301-307, 2006

Effects of Human Soluble BAFF Synthesized in Escherichia coli on CD4+ and CD8+ T Lymphocytes as well as NK Cells in Mice

X. SHAN1, L. CHEN1,2, M. CAO1, L. XU1, S. ZHANG1

1Jiangsu Province Key Laboratory for Molecular and Medical Biotechnology, College of Life Sciences, Nanjing Normal University, 2Jiangsu Engineering Research Center for Bio-medical Function Materials, Nanjing, Jiangsu, China China

Received date June 15, 2005
Accepted date August 1, 2005
On-line available August 5, 2005

B cell-activating factor belonging to the TNF family (BAFF, also called BLyS, TALL-1, zTNF-4, or THANK) is an important survival factor for B lymphocytes. In this study, we injected mouse abdominal cavity with human soluble BAFF (hsBAFF, 0.01, 0.1, 0.5, 2 mg/kg body mass) synthesized in Escherichia coli. On the 8th day after injection, we investigated the effects of hsBAFF on immune functional activities of splenic B lymphocytes, CD4+ and CD8+ T lymphocytes and natural killer (NK) cells in mice. The results showed that B lymphocyte proliferation significantly increased in hsBAFF-treated groups with dosages of 0.1 mg/kg (p<0.05), 0.5 and 2 mg/kg (p<0.01). We observed a dose-dependent increase of CD4+ T lymphocyte percentage and significantly higher values in 0.5 and 2 mg/kg hsBAFF-treated groups (p<0.05 and p<0.001, respectively) compared to control group, but CD8+ T lymphocyte percentage remained unchanged. The ratio of CD4+ to CD8+ T lymphocytes rose with increasing hsBAFF dosage (p<0.05 for 2 mg/kg hsBAFF vs. control). Significantly stronger NK cell activities were found in 0.5 and 2 mg/kg hsBAFF-treated groups (p<0.05). The main finding of this study is that the hsBAFF can enhance immune responses in the body by increasing B lymphocyte and CD4+ T lymphocyte function as well as elevating NK cell activity.

Key words
hsBAFF B lymphocyte CD4+ T lymphocyte CD8+ T lymphocyte NK cell

2006 by the Institute of Physiology, Czech Academy of Sciences