Murine Erythroleukemia Cell Line FBL as a Model for Cancer Immunotherapy

FBL is a murine erythroleukemia cell line of B6 origin that expresses the H-2^b-restricted Friend murine leukemia virus-derived Gag glycoprotein as a tumor associated antigen [9] (link), [28] . Gag peptide (CCLCLTVFL) and ovalbumin (SIINFEKL) control peptides were purchased from Pi Proteomics. Cell culture was conducted in complete RPMI-1640 with 10% FBS (Sigma). Fluorochrome-conjugated antibody to mouse CD8 (53–6.7) was purchased from eBiosciences. Fluorochrome-conjugated mouse antibodies to CD90.1 (OX-7), IFNγ (XMG1.2), TNFα (MP6-XT22), and human antibodies to CD4 (RPA-T4), CD8 (RPA-T8), and CD45RO (UCHL1) were purchased from BD Biosciences. Fluorochrome conjugated antibodies to mouse neuropilin-1 (761705) and human neuropilin-1 (446921) were purchased from R&D Systems. efluor-670 cell dye was purchased from Invitrogen. Anti-mouse Nrp-1A blocking antibody was provided by Genentech and administered intraperitoneally at 10 mg/kg every other day, similar to studies previously described [45] (link).