[Effects of mesenchymal stem cells on proliferation and apoptosis of allogeneic B lymphocytes].
OBJECTIVE
To study the influence of bone marrow mesenchymal stem cells (MSC) on the proliferation and apoptosis of allogeneic peripheral B lymphocytes in vitro.


METHODS
MSCs were isolated from the peripheral blood of healthy volunteer and cultured. B lymphocytes were isolated from another healthy volunteer and co-cultured with the MSCs at the B:MSC ratios of 50:1, 10:1, and 1:1 or with different concentrations of MSC supernatant (12.5%, 25%, and 50%) for 72 h, in the presence of antihuman IgM immunoglobulin goat antibodies (Anti-IgM) at a final concentration of 10 microg/mlL. The proliferation of B lymphocytes was analyzed with MTT assay. B lymphocytes and MSC were co-cultured at the ratio of 1:1 for 24 h or 48 h, with or without addition of Anti-IgM. Flow cytometric was used to detect the apoptosis of B lymphocytes.


RESULTS
The A value of B lymphocytes co-cultured with MSCs at different ratios were 0.521 +/- 0.093, 0.418 +/- 0.103, and 0.365 +/- 0.114 respectively. The A values of Group10:1 and Ggroup1:1 were both significantly lower than that of the control group (0.679 +/- 0.049, both P < 0.01), and the A value of Ggroup1:1 was significantly lower than that of Group10:1 (P < 0.05). The A value of B lymphocytes co-cultured with 50% MSC supernatant was 0.504 +/- 0.099, significantly lower than those of the control group and Group 12.5% (both P < 0.05). MSCs didn't induce apoptosis of B lymphocytes. The apoptosis rates of B lymphocytes co-cultured with MSCs for 24 h or 48 h, in presence or absence of Anti-IgM were 1.90% +/- 0.75%, 2.33% +/- 1.01%, 2.33% +/- 0.75%, and 1.39% +/- 0.63% respectively, without significant difference between any 2 of the four groups.


CONCLUSIONS
MSC and its supernatant inhibit B lymphocyte proliferation with the mechanism correlated with the MSC concentration and the MSC-secreted cytokine, but MSCs does not induce B lymphocytes apoptosis in vitro.
Wu
Ling-qi
LQ
Department of Hematology, Hematology Center of Chinese General Hospital of Lanzhou Command of People's Liberation Army, Lanzhou 730050, China.
Bai
Hai
H
Wang
Cun-bang
CB
Yang
Xiao-liang
XL
Zhao
Qiang
Q
Yang
Yi-wu
YW
Lin
Mei
M
D017209:Apoptosis; D001402:B-Lymphocytes / Q000166:cytology*; D001854:Bone Marrow Cells / Q000166:cytology; D002454:Cell Differentiation; D049109:Cell Proliferation; D018920:Coculture Techniques; D006801:Humans; D059630:Mesenchymal Stem Cells / Q000166:cytology*