Abstract: Ｏｂｊｅｃｔｉｖｅ：To study the variation of immunosuppression of HeLa inoculated by LHC. Methods：HeLa was inoculated by LHC，for 48 h，the supernatants were collected（LHC-S1），after centrifuging the cellｓ，and then adjusted the concentration of HeLa，inoculated for 48 h，centrifuged cells, collect the supernatants（ＬＨＣ－Ｓ２），adjusted the concentration of HeLa，inoculated for 48 h, after centrifuging the cells collected the supernatants（LHC-S3）. Compared with the HeLa′s supernatant without LHC, which was inoculated in the same condition, collected the supernatant for 3 times（Control -S1, Control -S2, Control -S3）, test the TGF-β1 and IL-10 by ELISA, PGE2 by ultraviolet spectrophotometry, by means of MTT to detect the proliferation of PHA induce PBMC and antibody-dependent cellular cytotoxicity of CTL. Flow cytometry （ＦＣＭ） ｔo analyze the subpopulation of peripheral blood lymphocytes, which was inoculated by the supernatants. Results：（１）The TGF-β1，IL-10 and PGE2 A278 nm of control group had no significant difference in statisticｓ（Ｐ＞０．０５）；ｉｎ LHC-group the difference were statically significant(P＜0.05); TGF-β1 gradually decreased, IL-10 was similarity in LHC-S1 and LHC-S２，ｌess than that in LHC-S3, PGE2 A278 nm was the minimum in LHC-S２；except in LHC-S2，IL-10 was less than the control grouｐ. （2）All the supernatants of the control group could inhibit the proliferation of PHA induced PBMC and cytotoxicity of CTL, had no significant statistic difference（P＞0.05）, the inhibition to CTL in LHC group and corresponding control group had no significant statistic difference（P＞0.05）; in LHC group, the inhibition ratio in LHC-S1 was the lest. （3）All the supernatants could influence the expression of the subpopulation of lymphocyte, it had statistic difference（P＜0.05）; Compared with control group, the percentage of CD3+，CD4+，CD25+ and CD4+CD25- increased in LHC-S1 and LHC-S2 group, the percentage of CD4+CD25+ decreased（P＜0.05), in the LHC-S3 group，ｔhe difference was not significant（P＞0.05）. Conclusions：The immunosuppressive molecules of HeLa could be reduced by LHC; LHC could decrease the inhibition of the proliferation of PHA induce PBMC; LHC also could increase the percentage of CD3+，CD4+，CD25+ and CD4+CD25-, reduce CD4+CD25+; LHC could reverse the immunosuppression of HeLa to a certain degree.

Key words: Tetramethylpyrazine, HeLa cells, Immune tolerance, Tetramethylpyrazine, HeLa cells, Immune tolerance