Study Of The Effect Of Astragalus Polysaccharides On The Density Of Epidermal Langerhans Cell Of SLE Mice

IntroductionLangerhans cell(LC) is a group of dendritic cells in the epidermis. Many experiments have proved that LC is the antigen presenting cell(APC) that play an important role in initiating the immune reaction of the skin. Its main biological function is to provide sensitization signals to various antigens. Many factors affect the number and function of LC ,such as corticosteroids and X ray.Our study showed that the linear density of LC in the normal -appearing SLE skin increased, and the dendrities are delicate whereas the linear density of LC in the lesional skin decreased and the dendrities are clumsy. The numbers of LC in untreated SLE patients with newly developed skin lesions decreased in the central lesional sites and increased significandy in the peripheral lesional sites. In MRL/ Ipr mice which occur SLE spontaneously, the LC numbers increased significandy in the central lesional sites but decreased with the development of the disease and increased in the peripheral sites, which indicate that the number of LC are related with the skin lesion of human SLE and MRL/lpr mice.Astragalus polysaccharides can increase the humoral, cellular and nonspecific immune function. It can also protect the body against infection and facilitate the hemopoietic function. Recent study sug-gests that Astragalus polysaccharides increase the production of CM -CSF and GM - CSF or TNF - a may increase the epidermal LC density , indicating that Astragalus polysaccharides may take part in regulating the LC density.In order to study the effect of Astragalus polysaccharides on (NZBxNZW)F1 mice, we examined the density of epidermal LC with immunohistochemical technique.Materials and Methods25 (NZBxNZW)Fl mice are divided into four groups. Normal saline ( NS) group: injecting NS 0. 2ml intraperitoneally everyday; Dexamethasone group; injecting Dexamethasone 1 mg/kg intraperitoneally everyday; Astragalus polysaccharides ( PG2 ) group I ; injecting PG2 25mg/kg intraperitoneally everyday; Astragalus polysaccharides (PG2) group II : injecting PG2 50mg/kg intraperitoneally everyday; Immunohistochemical method to examine the epidermal LC density. Statistical analysis :t test.Results1. There was no difference of 0X3 positive LC density between NS group SUE mice and that of the C57BL/6 mice; 0X4 positive LC density of NS group SLE mice increased compared with that of C57BI/6 mice.2. Compared with all the other groups both the 0X3 positive LC density and 0X4 positive LC density of Dexamethasone group SLE mice decreased significantly.3. There was no significant difference of 0X3 positive LC density between PG2 group I SLE mice and that of the C57BL/6 mice; 0X4 positive LC density of PG2 group I SLE mice increased compared with that of the C57BL/6 mice; There was no significant difference of 0X3 positive or 0X4 positive LC density between PG2 group I SLE mice and that of the NS group SLE mice; Both 0X3 positive and 0X4 positive LC density of PG2 group I SLE mice increased significantly compared with that of the Dexamethasone group SLE mice.4. There was no significant difference of 0X3 positive LC density between PG2 group II SLE mice and that of the C57BL/6 mice; 0X4 positive LC density of PG2 group II SLE mice increased compared with that of the C57BL/6 mice; There was no significant difference of 0X3 positive or 0X4 positive LC density between PG2 group II SLE mice and that of the NS group SLE mice and the same with PG2 group I SLE mice; Both 0X3 positive and 0X4 positive LC density of PG2 group II SLE mice increased significantly compared with that of the Dexamethasone group SLE mice.DiscussionOur experiment showed that there was no significant difference of LC density between SLE mice and that of the non - SLE mice, Dexamethasone inhibit the expression of LC whereas Astragalus polysaccha-rides have no effect on LC density.Langerhans cell is the dendritic antigen presenting cell which take part in the immune reaction of the skin. When antigen enter the skin, epidermal LC takes up t...