SD-4 deficiency had no impact on the intrinsic T-cell response to TCR-induced signals, but enhanced these cells’
BMN 673 research buy responsiveness to APC. Moreover, we showed SD-4 to be a constitutive inhibitor of allo-reactive T cells responsible for GVHD. Hence, SD-4 can be targeted to treat GVHD by increasing the efficacy of allo-HSCT therapy. Female BALB/c and C57BL/6 (6–8 weeks old) mice were purchased from Harland Breeders (Indianapolis, IN), and OT-II transgenic mice were purchased from Taconic Farms (Hudson, NY). Pmel-1 TCR transgenic mice (B6.Cg-Thy1a/CyTg(TcraTcrb)8Rest/J) were bought from Jackson Laboratory (West Grove, PA). SD-4-deficient mice were produced by mating SD-4+/− mice bearing a C57BL/6 genetic background. We also produced SD-4-deficient pmel-1 mice by breeding SD-4−/− and pmel-1 transgenic mice. Control groups included mice with wild-type (WT) genotype (SD-4+/+) from the same generation of backcrosses. Following National Institutes of Health guidelines, mice were housed and cared for in a pathogen-free facility and subjected to experimental procedures approved by the Institutional Animal Care Use Center at The University of Texas Southwestern Medical Center (Dallas, TX). Monoclonal antibodies (mAb) against CD3 (145-2C11), CD4 (RM4-5), CD8 (53-6.7), CD11c (N418), CD19 (eBio 1D3), PD-1 (J43), Foxp3 (FJK-165) and H-2Kb-SIINFEKL (eBio25-D1.16) were purchased from eBioscience (San Diego, CA); mAb against
SD-4 (KY/8.2) were from BD Pharmingen (San Diego, CA); secondary antibodies were obtained from Jackson MG 132 ImmunoResearch (West Grove, PA); and hgp100 peptide (KVPRNQDWL), ovalbumin(257–264)
(OVA257–264) H-2Kb-restricted class I peptide (SIINFEKL), and OVA323–339 H-2Kb-class II peptide (ISQAVHAAHAEINEAGR) were synthesized by the Protein Chemistry Technology Center at UT Southwestern. For flow cytometry, lymph node cells or T cells (5 × 105 to 10 × 105) were treated with 5 μg/ml Fc blocker (BD Pharmingen) on ice for 30 min and incubated science with primary antibody (5–10 μg/ml), followed by addition of secondary antibody (2·5 μg/ml). After washing, cell-bound fluorescence was analysed by FACSCablibur (BD Biosciences, San Jose, CA). DC-HIL-Fc, comprising the extracellular domain fused to the Fc portion of human IgG1, was produced in COS-1 cells and purified as described previously. Purity of final preparations was high, as judged by a single band in SDS–PAGE/Coomassie Blue staining or in immunoblotting with anti-DC-HIL mAb or goat anti-human IgG antibody. CD3+, CD4+ and CD8+ T cells were purified from spleen using pan-T-cell, CD4+ and CD8+ T-cell isolation kits (Miltenyi Biotec, Auburn, CA), respectively, according to the manufacturer’s recommendations. For binding of DC-HIL-Fc to T cells, CD4+ or CD8+ T cells (1 × 106) purified from spleens of WT or KO mice were activated by culturing with immobilized anti-CD3 antibody (1 or 3 μg/ml) for 3 days.