[The effect of B lymphocytes on immune response of periodontal bacteria and osteoclast differentiated reactor-RANKL expression].
OBJECTIVE
To study whether B lymphocytes involve in bone resorption in periodontal disease by evaluating RANKL expression of B lymphocytes in immune response to aggregatibacter actinomycetemcomitans (Aa).


METHODS
The expression of mRNA transcripts involved in day 1 and day 7 responses of cytokines in cultured rat splenocytes was determined by RT-PCR; The percentage of RANKL-expressing IgG positive cells by B cells in cultured rat splenocytes was measured by flow cytometry; and B lymphocytes capacity for induction of osteoclast differentiation was evaluated by TRAP staining. SPSS 10.0 software package was used for statistical analysis.


RESULTS
The expression of IL-4 and IL-10 in cultured cells was not changed in the presence of Aa on day 1, after culture for 7 days; The percentage of B lymphocytes, all RANKL mRNA transcripts and percentage of RANKL-expressing IgG positive cells were significantly increased in the presence, compared to the absence of Aa. These increases were considerably greater in cells isolated from immunized than non-immunized rats. B cells from Aa immunized rats significantly increased induction of osteoclast differentiation (P<0.01), and addition of human OPG-Fc into the culture significantly inhibited its induction (P<0.05), and was RANKL-independent.


CONCLUSIONS
B lymphocytes contribute to bone resorption in periodontal disease through involving in the immune response to Aa, up-regulation of RANKL expression and increasing induction of osteoclast differentiation.
Lin
Xiao-ping
XP
Department of Stomatology, Shengjing Hospital of China Medical University. Shenyang 110004, Liaoning Province, China. Xiaoping_ba@yahoo.com
Han
Xiao-zhe
XZ
Wei
Wei
W
Martin A
Taubman
T
D016976:Aggregatibacter actinomycetemcomitans; D000818:Animals; D001402:B-Lymphocytes; D002454:Cell Differentiation; D002478:Cells, Cultured; D006801:Humans; D010010:Osteoclasts; D053244:Osteoprotegerin; D053245:RANK Ligand; D012333:RNA, Messenger; D051381:Rats
D053244:Osteoprotegerin; D053245:RANK Ligand; D012333:RNA, Messenger