28 These findings prompted us to investigate the effects of B7-H3-transduced tumour cells on anti-tumour immunity, because Erlotinib datasheet CD8+ T cells are the major effector cells in most cases of tumour eradication. In this study, we examined mechanisms of enhanced anti-tumour immunity induced by tumour-associated B7H3 and the involvement of its TLT-2 receptor. Female C3H/HeN, DBA/2, BALB/c, C57BL/6 (B6) and BALB/c nude mice were purchased from Japan SLC (Hamamatsu, Japan), Charles River Japan (Tokyo, Japan) and CLEA Japan (Tokyo, Japan). Chicken ovalbumin (OVA)257–264-specific TCR transgenic OT-I mice
were generously provided by Dr William R. Heath (The Walter and Eliza Hall Institute of Medical Research, Victoria, Australia).30 Mice were 6–10 weeks of age at the start of the experiments. All experiments were approved by the Animal Care and Use Committee of Tokyo Medical and Dental University. The T lymphoma EL4, OVA-expressing
EL4 (E.G7), plasmacytoma J558L, mastocytoma P815 and melanoma B16 cell lines were cultured in RPMI-1640, supplemented with 10% fetal bovine serum and 10 μg/ml gentamicin. A squamous cell carcinoma SCCVII cell line was maintained Venetoclax in Dulbecco’s modified Eagle’s medium with 10% fetal bovine serum and 10 μg/ml gentamicin. Anti-B7-H3 [MIH32 and MIH35, both rat immunoglobulin G2a (IgG2a), κ] and anti-TLT-2 mAb (MIH47, rat IgG2a, κ and MIH49, rat IgM, κ) were generated as described previously.28 These mAbs were biotinylated or conjugated with fluorescein isothiocyanate (FITC), according to a standard protocol. Peridinin-chlorophyll-protein complex-carbocyanin 5.5 (PerCP-Cy5.5) -conjugated-anti-CD4 (GK1.5), anti-CD8 (53-6.72), and anti-CD3 (145-2C11); FITC-conjugated anti-CD45 (3F11.1); anti-major histocompatibility complex (MHC) class I (SF1-1.1, 36-7-5 and AF6-88.5 for Kd, Kk and Kb, respectively); phycoerythrin-conjugated for anti-CD8 (53-6.72),
anti-CD25 (PC61), anti-CD69 (H1.2F3), anti-CD54 (YN1/1.7.4), anti-CD80 (1G10) and anti-CD86 (GL1) mAbs; and appropriate fluorochrome-conjugated isotype control immunoglobulins were used. All fluorochrome-conjugated antibodies except FITC were obtained from eBioscience (San Diego, CA) or BD-Pharmingen (San Diego, CA). Culture supernatant from the 2.4G2 hybridoma (anti-CD16/CD32 mAb) was used to block Fc-mediated binding. Phycoerythrin-streptavidin or allophycocyanin-streptavidin was used for the biotinylated mAbs. Cells were stained and analysed using a fluorescence-acitvated cell sorter (FACSCalibur; BD Biosciences, Sparks, MD) and the CellQuest (BD Biosciences) or flowJo (TreeStar, Ashland, OR) software. Mouse B7-H3 complementary DNA28 was inserted into the pMKITneo, pMXC and pMXs-neo (kindly provided by T. Kitamura) expression vectors.