3.2. KIR expression on T cell subse

3.2. KIR expression on T cell subsets in human pregnancyKIR expression on cPBL, mPBL, decidua basalis and decidua parietalis T cells was analyzed using antibodies against the HLA-C2 specific KIR, CD158a/h and the HLA-C1 specific KIR, CD158b/j. The percentage of CD158a/h+ cells and CD158b/j+ cells was determined within the CD4-CD8-, CD8+ and CD4+ T cell subsets (Fig. 2a and b). As a positive control, analysis of CD158a/h and CD158b/j expression on CD3-CD56+ NK cells was included. In all samples the frequency of CD158a/h+ and CD158b/j+ cells was higher in CD4-CD8- T cells compared to CD8+ T cells. The lowest frequency of CD158a/h+ and CD158b/j+ was observed within the CD4+ T cells. Both decidua basalis and decidua parietalis CD4+ T cells contained a significantly higher proportion of CD158a/h+ cells and CD158b/j+ cells compared to CD4+ T cells in cPBL and mPBL. Besides the percentage of CD158+ cells, the Mean Fluorescence Intensity (MFI) of the CD158+ cells was determined. The MFI of CD158a/h and CD158b/j expression was significantly increased on decidual NK cells in comparison with peripheral NK cells (Fig. 2c and d). Furthermore, The MFI of CD158a/h but not the MFI of CD158b/j was significantly increased in decidual CD4+CD158a+ T cells in comparison to peripheral blood CD4+CD158a/h+ T cells (Fig. 2c). Further phenotypic analysis showed that CD4+KIR+ and CD8+KIR+ T cells mainly express the αβTCR, whereas CD3+CD4-CD8- KIR+ T cells contained both αβTCR+ and γδTCR+ T cells (Fig. 3). The CD8+KIR+ and CD4-CD8-KIR+ T cells were mainly found within the CD28- T cell population whereas CD4+KIR+ T cells were found within the CD28+ and CD28- fractions (Fig. 3). Analysis of expression of CD158a/h and CD158b/j on αβTCR+ T cells and γδTCR+ T cells showed a significant increase in MFI of CD158a/h and CD158b/j on the αβTCR-/γδTCR+ T cells (Fig. 3c and d).