Objective:To evaluate the effect on immunomodulation of tea polyphenols(TP)

and to study the influence of tea polyphenols on the immune factor in the atheroscterotic plaque lesion in rabbits.Methods:Forty male true-bred New Zealand rabbits were randomly divided into five groups:normal control group(NC)

atherosclerosis model control group(ASC)

low dose of TP group(LTP)

high dose of TP group(HTP)and simvastatin group(Sim).The structural change of artery

the deposit of IgG and IgM and the infiltration of macrophage in plaque lesions of AS were analyzed by hematoxylin and eosin staining and immunohistochemistry.Results:Plaque lesions of AS were obvious after 12-week high-cholestrol feeding.The IC of IgG accumulated in plaque lesions

while the IC of IgM was not detected.The IC of IgG mainly localized in the core and the shoulder of mature plaque lesions and macrophage were greatly infiltrated in the plaque lesions.In comparison with other groups

the expression of IgG and macrophage in the plaque lesions were stronger in atherosclerosis model group(P<0.05).High and low dose of TP could depress the expression of IgG and macrophage in the plaque lesions. The depressing amplitude in HTP group was more than that in LTP group(P<0.05)

but there was no difference between HTP group and Sim group.Conclusion:The IC of IgG and the macrophage exist in the plaque lesions of AS.The IC and the macrophage are closely related to the origin and progress of AS.The tea polyphenols can inhibit the formation of IC and depress the expression of macrophage in the plaque lesions through its effect on immunomodulation

and to some degree

the effect has dose-effect relationship.