Differential Contribution of BLT₁ and BLT₂ to Leukotriene B₄-Induced Human NK Cell Cytotoxicity and Migration

Figure 1

Expression of BLT₁ and BLT₂ in NK cells. RT-PCR of BLT₁, BLT₂, and GAPDH from PBLs, isolated NK cells, and monocytes were analyzed by agarose gel electrophoresis (a): lanes 1 and 2, human BLT₁ and BLT₂ cDNAs as positive controls; lane 3, polymerase-only, RT-negative samples for each oligonucleotide pair; lane 4, PBL mRNA; lane 5, NK cell mRNA; and lane 6, monocyte mRNA. (b) Expression levels of BLT₁ and BLT₂ mRNA were determined by densitometry and the ratio to GAPDH (the mean ± the SEM) from six donors is shown. (c) Whole cell and cell-surface expression of BLT₁ (top and middle rows, resp.) and whole cell expression of BLT₂ (bottom row) on PBLs, NK cells, and monocytes were measured by flow cytometry as described in Section 2. In the overlaid histogram graphs, grey background indicates control histograms, where cells were incubated with Ig isotype, and solid line indicates cells incubated with anti-BLTR antibodies. (d) Results represent the percentage of BLTR positive cells as population comparison analysis. Bars represent means ± SEM of ten to seventeen independent experiments. (e) Coexpression of BLT₁ and BLT₂ was measured as the percentage of events that were BLT₁ and BLT₂ double positive, gating on PBLs and NK cells (CD56⁺), respectively. Bar graphs represent means ± SEM of four independent experiments. ; ; , paired Student’s -test.