Contact Hypersensitivity And The Balance Of Th1/Th2 Lymphocyte Subsets

Object Contact hypersensitivity (CH) is a prototype of Th cell mediated delayed-type hypersensitivity (DTH) reaction. Th cells can be divided into Thl and Th2 according to the cytokines they secrete. In classical contact hypersensitivity, Thl cells produce interleukin-2 (IL-2), interferon- y (IFN- y) and tumor necrosis factor- 13 (TNF- 13), which contribute to CH, whereas Th2 cells produce JL-4, IL-5, JL-13, by which CH is negatively regulated. Thl and Th2 subsets can produce different cytokines. The different cytokines can interact, which make up of the balance of Thl/Th2 cells and regulate the production of IgE. Recently several cell surface markers of Th 1 and Th2 were studied such as chemokine receptor 5 (CCRS) and CD3O, which have a nearly correlation with Thl and Th2 cells. To investigate the immunological pathogenesis of classical contact dermatitis and seasonal contact dermatitis, the cell surface markers, CCR5 and CD3O, and the cytokines IL-4 , IL-1O, IFN- y and total serum IgE of patients were evaluated. Methods 1. Patients with seasonal contact dermatitis (SCD) and non-seasonal contact dermatitis (NSCD) were collected in outpatient. The health control (HC) was selected in volunteer in our hospital. 2. The serum total IgE level of the patients was detected by IRMA. 3. Lymphocytes were isolated from peripheral blood by density gradient centrifugation on Ficoll-Hpaque, and suspended at 2.0X106 cells/mi with 15%FCS-1640, supplemented with lOOug/ml PHA. Cells were cultured at 37 0C in a 5%C02 humidified atmosphere for 48 hours. 4. The lymphocytes both stimulating with PHA or without PHA were incubated with mouse anti human antibodies: CCR5-FITC, CD3O-PE, CD4-CHROME in i.0x106 cells/mi and detected by immunofluorescent marker-flowcytometry. 5 .The supernatant of cultured cells was harvested and stored at ?0 0C. The ELISA was used to assess for cytokines. Optical density was read at 450nm. 6.Data were analyzed statistically by x2 test and t test. Result 1. The level and positive rate of total serum IgE in SCD were higher than those in NSCD (P<0.05) and HC (P<0.0 1). There was no significant difference between NSCD and HC (P>0 .05). 2. The results of the detecting of the expression of CCR5 as follows: (1) Before stimulating with PHA, the number of CD4~CCR5~ lymphocytes of SCD was lower than that of HC (P<0.01) while that of NSCD was higher (P<0.05); (2) After stimulating with PHA, the number of CD4~CCR5~ lymphocytes of SCD was higher than that of HC (P<0.0 1), but still lower than that of NSCD (PO.05). 4.The level of IFN- y in SCD was lower (P<0.05) while in NSCD was higher (P<0.O1) than that in HC. 5.The level of IL-4 in SCD was higher (P