Distribution of CD150 mRNA and plasma membrane expression on T-cell and macrophage activation.

(A) Real-time RT-PCR analysis of CD150 expression on mouse lymphocyte subsets and lymphoid organs. RNA was extracted from the indicated cell types isolated and quantitative RT-PCR performed with the primers and probes described in “Materials and methods.” (B) CD150 is rapidly up-regulated on splenic T cells following activation. Purified CD3⁺ splenic T cells were stimulated with 5 μg/mL Con-A with the addition of 50 U/mL IL-2 for the indicated periods. CD150 is present on the surface of activated T cells as early as 12 hours following stimulation; data are representative of 3 separate experiments. Double staining with anti-CD69 and anti-CD150 during the activation time course (right panels) shows that CD150 is predominantly on CD69⁺ T cells after activation (clear histograms indicate CD69⁺ cells, black histograms indicate the CD69⁻ population). (C) CD150 is up-regulated on F4/80⁺ murine peritoneal macrophages following activation with 100 ng/mL LPS and 50 U/mL IFN-γ. FACS analysis with FITC-conjugated 9D1 (anti-mCD150) and F4/80.