After 8 weeks, the culture expanded to approximately 106 cells and was used for experiments. Ethics We complied with all relevant ethical regulations for work with human participants. and subsequent IKK2 activation. The tumor progression locus 2 (TPL2) kinase is induced by LMP1 via IKK2 and transmits JNK activation signals downstream of IKK2. The IKK2-TPL2-JNK axis is specific for LMP1 and differs from TNF, Interleukin?1 and CD40 signaling. This pathway mediates essential LMP1 survival signals in EBV-transformed human B cells and post-transplant lymphoma, and thus qualifies as a target for treatment of EBV-induced cancer. gene was targeted in HEK293 cells. Three different TPL2-deficient HEK293 clones were transfected with LMP1 wildtype or the AAA/Y384G mutant together with HA-JNK1, and JNK1 activity assays were performed. JNK activation by LMP1 was substantially reduced in all three knockout mice64. SGI 1027 The lymphoblastoid cell line LCL 1C3 (provided by J. Mautner) was generated by infection of primary human B cells with B95.8 EBV. BL41:NGFR-LMP1wt cells (provided by SGI 1027 J. Mautner), EBV-negative BL41 Burkitt lymphoma cells and LCL721 have been described and were taken from own laboratory stocks65C67. The transgene (tg)-positive carcinoma cell line 53.234a and corresponding tg mice or genes of PTLD099 and PTLD880 were amplified by PCR and the signaling domains were sequenced. Primer sequences are given in Supplementary Table?1. Lymphoblastoid cell line LCL877 was derived from primary cells of the same PTLD biopsy that gave rise to PTLD880, but was infected with EBV laboratory strain B95.8. Cells obtained as described above were plated in medium with cyclosporine A containing 10?l/well of filtered (0.7?m) supernatant from EBV-producing cell line B95.8. Cells were further cultivated and expanded as described above for PTLD cell lines. LCL.NGFR-LMP1.6 cells were established by infection and conditional transformation of peripheral blood B cells of an adult EBV-negative donor with recombinant maxi-EBV 2264.19, carrying NGFR-LMP1 instead of wildtype LMP153. Initial outgrowth of infected B cells was FRAP2 supported by plating PBMCs on top of an adherent layer of irradiated LL8 mouse fibroblasts expressing human CD40L68. At day 14, the cells were removed from the feeder layer and since then continuously cultivated in the presence of crosslinking antibodies (see NGFR-LMP1 crosslinking) to maintain LMP1 signals and proliferation. After 8 weeks, the culture expanded to approximately 106 cells and was used for experiments. Ethics We complied with all relevant ethical regulations for work SGI 1027 with human participants. Anonymised human being PTLD biopsies and blood from a healthy human donor were obtained with educated consent as authorized by the Institutional Review Table (Ethics Commission of the Faculty of Medicine of the Ludwig-Maximilians-University Munich, project no. 071C06C075C06). Plasmids The SGI 1027 plasmids pCMV-HA-LMP1 wildtype, pCMV-HA-LMP1(AAA/371C386) harboring a P204xQxT to AxAxA mutation within CTAR1 and lacking the 16 C-terminal amino acids of CTAR2, pCMV-HA-LMP1(AAA/Y384G), pSV-LMP1, pSV-LMP1(Y384G), pcDNA3-Flag-IKK2, and pRK5-HA-JNK1 have been explained16,49. The vector pSV-NGFR-LMP1 encoding a fusion protein of aa 1C279 of human being low affinity p75 NGF-receptor and aa 196C386 of LMP1 has been explained17,48. pCMV5-TPL2wt.MT (provided by C. Patriotis) and pcDNA3-Flag-p105 (provided by D. Krappmann) have been explained69,70. The vector pEF4C-3xFlag-IKKwt (NEMO) was a kind gift of D. Krappmann. pRK5-HA-Ubiquitin K63 (all lysines mutated to arginines except of K63) was from Addgene and has been explained71. Retroviral transduction NGFR-LMP1 wildtype and NGFR-LMP1(Y384G) were subcloned from pSV-NGFR-LMP1 into the retroviral vector pSF91-IRES-GFP-WPRE (provided by C. Baum)72. For disease production, phoenix-gp cells were transfected with pSF91-NGFR-LMP1-IRES-GFP-WPRE, gag-pol vector and pEcoEnv expressing ecotropic Env protein as explained21. MEFs were infected and sorted for low and similar GFP expression levels using a MoFlo cell sorter (Beckman Coulter). NGFR-LMP1 manifestation at.