T lymphocytes express TSP-1 and CRT on the cell surface. (A) TSP-1 expression in T-cell lines (CCRF HSB2, Molt-4, P30, and Peer) and normal peripheral blood T cells (PBTs; 93% CD3⁺) in suspension as detected by gel analysis (6% SDS-PAGE) of immunoprecipitated material from biotinylated cells using 2 different monoclonal antibodies to TSP-1. The cell lines were cultured with and without SDF-1α for 30 minutes before biotinylation. (B) SDS-PAGE gels (6%) showing CRT and TSP-1 in normal T cells (96% CD3⁺) allowed to adhere to a fibronectin-coated (10 μg/mL) surface for 15 minutes before biotinylation and immunoprecipitation. The cells had been incubated with or without anti-CD3 and a cross-linking anti-immunoglobulin for 30 minutes before the adhesion. (C) Detection of TSP-1 and fibronectin after blotting of SDS-PAGE–separated material from T cells in suspension cultured in RPMI with 10% FCS or in AIM-V, respectively. (D) Relative expression of mRNA for CRT, TSP-1, and CD91 in T cells determined by real-time PCR. CCRF HSB2, AF24, and PBTs show significant mRNA expression for all 3 proteins. One representative experiment of 2 to 8 independent experiments is shown.