When lysates from vector transduced cells were subjected to the same analysis, an immunor eactive protein of approximately 80 kD was detected. We attribute the apparent difference in the size of the mature, secreted form of the sTNFR CB-7598 Fc protein relative to its the intracellular form to post translational modifi cation of the protein during the secretion process. To m the level of sTNFR Fc in culture supernatants, transduced cells were seeded at a density of 1. 0 �� 106 cells mL in a 25 cm2 flask and cultured at 37 C for 24 h. The supernatant was then collected and sTNFR Fc protein was quantified by ELISA. Results indicated that concentration of the sTNFR Fc in the supernatant of CHME 5 T1 cells was 80 2 ng mL, after the second transduction of the cells, the concentration increased to 117 3 ng mL.

The sTNFR Fc level in the supernatant from transduced HTB 11 cells was roughly 5 fold higher, at 520 5 ng mL, Inhibitors,Modulators,Libraries following a single transduction. Importantly, sTNFR Fc expression was not detected in media collected from non transduced Inhibitors,Modulators,Libraries nor mal CHME 5 Inhibitors,Modulators,Libraries and HTB 11 cells under the same condi tions. To examine the stability of the sTNFR Fc expression and secretion, the transduced CHME 5 and HTB 11 cells were serially subcultured Inhibitors,Modulators,Libraries 20 times, and sTNFR Fc levels in the conditioned supernatants were measured by ELISA at every 5th passage, with supernatants collected from corresponding non transduced cells being used as negative controls. No significant reduction in the sTNFR Fc expression levels was detected over the course of the 20 passages.

The percentage of GFP positive cells in these transduced cell popula tions was also evaluated every five passages, and found to be stable over the course of the 20 passages. These results suggest that the lentiviral vector mediated transduction and sTNFR Fc secretion was stable and remained at high levels over a prolonged time period. Potential adverse Inhibitors,Modulators,Libraries impact To determine whether transduction with the lentiviral TNFR Fc vector resulted in any adverse impact on tar get cells, the transduced cells were examined for their growth except kinetics and morphology. There were no obvious alterations in cell morphology following transduction, which remained unchanged at different passage numbers. Subsequent MTT assays also indicated that there was no statistically significant difference in cellular viability between transduced and non transduced control cells. We also evaluated whether vector mediated transduc tion of CHME 5 or HTB 11 cells resulted in their inflammatory activation. To do this, we measured and compared endogenous TNF a release by cells trans duced with a control lentiviral vector encoding the Fc fragment alone, or non transduced cells.