Objective   To observe the effects of human Augmenter of liver regeneration (hALR) on the expressions of PKCα

NF-κB and IL-2 in human peripheral blood mononuclear cells (PBMC) and to evaluate the immunosuppressive mechanism of hALR.   Methods   PBMCs were isolated from healthy volunteers by gradient centrifugation and were divided into normal control group (N)

ConA stimulated group (ConA group) and hALR interfering group (ConA+hALR group). Cells in the ConA group were stimulated by ConA (5 μg/ml) to proliferate and to secret IL-2. ConA+hALR group was interfered by hALR at the dose of 30 μg/ml. After cells were cultured for 0

8

16

32 and 40 h

the cell proliferation was detected by MTT assay. The expressions of PKCα and NF-κB were detected by Western blot analysis. The concentration of intracellular calcium was determined according to uploading of probe Fluo-3AM. The concentration of IL-2 in the supernatants was detected by ELISA method.    Results   Cells in the ConA group proliferated gradually and peaked at 16 h with statistical significance as compared with cells in normal control group (P0.05). The expressions of PKCα and NF-κB in the PBMC were upregulated

which was concordant with the increase of IL-2 in the supernatant

and peaked at 16 h (P0.05). Cell proliferation in hALR interfering group was not observed and the peak of PKCɑ，NF-κB and IL-2 were postponed from 16 h to 32 h. There was no significant difference of intracellular calcium between the 2 groups at these time points.   Conclusion   hALR may inhibit the secretion of IL-2 by suppressing the pathway of PKCα-NF-κB and thus results in inhibition of  immune response.