[Effect of high mobility group box 1 protein on proliferation and apoptosis and balance between Th1/Th2 and Tc1/Tc2 of lymphocytes in vitro].
OBJECTIVE
To explore whether extracellular high mobility group B1 protein (HMGB1) plays a role in regulation of lymphocyte-mediated immune.


METHODS
Lymphocytes originated from mice spleens were stimulated with concentration gradient HMGB1 or combined with ConA in vitro. Then, the proliferation of lymphocytes was assayed with MTT, quantitative and qualitative analysis of apoptosis in lymphocytes and expression of CD3 and CD8 on cells surface and IL-4 and IFN-gamma within cells were assessed using flow cytometry. Levels of interleukin-2 (IL-2) and soluble IL-2R (sIL-2R) of culture supernatant were assayed by ELISA.


RESULTS
(1) HMGB1 regulated the proliferation of lymphocytes in a time- and dose-dependent manner, but did not influence the apoptosis of lymphocytes. (2) The ratio of Th to Tc increased from 2.6:1 at culture-hour 0 to 5-7:1 at culture-hour 12 and 24, but that did not change with the stimulation of HMGB1. There were no significant difference in the population and percentage of Th1 and Th2, as well as Tc1 and Tc2, when stimulated with HMGB1. However, HMGB1 in concentrations of 10 and 100 microg/L favored Th1 differentiation, and 1 and 10 microg/L HMGB1 favored Tc1 differentiation. (3) Levels of IL-2 were increased, and sIL-2R decreased, significantly, when stimulated with 10 microg/L HMGB1 for 12 h, thus the ratio of IL-2 to sIL-2R was markedly higher, as compared with 0 and 1000 microg/L HMGB1 (P<0.05 or P<0.01).


CONCLUSIONS
Low dose HMGB1 could be in favor of the bias of Th1 and Tc1, and improve the lymphocyte-mediated immune.
Wang
Zhong-tang
ZT
Department of Plastic Surgery, Zhongshan Hospital, Xiamen University, Xiamen 361004, China. wangkingking@hotmail.com
Yao
Yong-ming
YM
Sheng
Zhi-yong
ZY
D000818:Animals; D017209:Apoptosis / Q000187:drug effects*; D017252:CD3 Complex / Q000378:metabolism; D016827:CD8 Antigens / Q000378:metabolism; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D024243:HMGB1 Protein / Q000494:pharmacology*; D007371:Interferon-gamma / Q000378:metabolism; D007376:Interleukin-2 / Q000378:metabolism; D053645:Interleukin-2 Receptor alpha Subunit / Q000378:metabolism; D008214:Lymphocytes / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D013602:T-Lymphocytes, Cytotoxic / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D018417:Th1 Cells / Q000166:cytology* / Q000187:drug effects / Q000276:immunology; D018418:Th2 Cells / Q000166:cytology* / Q000187:drug effects / Q000276:immunology
D017252:CD3 Complex; D016827:CD8 Antigens; D024243:HMGB1 Protein; D007376:Interleukin-2; D053645:Interleukin-2 Receptor alpha Subunit; D007371:Interferon-gamma