FIG. 4.

TERT-immortalized GE secrete inflammatory cytokines in response to rhTNF-α in a similar manner to GE constructed from primary cells. Primary (GE-Prim; gray bars) and TERT-immortalized (GE-TERT, black bars) human GEs were grown as described in the Materials and Methods section and then cultured for 24 h in the presence or absence of different concentrations of rhTNF-α. Cytokine IL-6, CXCL8, and CCL2 secretion into culture supernatants was determined with ELISA. Data represent the average of three individual donors for GE-Prim and three different passages of immortalized cells between passage 30 and 50 ± SEM; *p < 0.05; **p < 0.01; two-way ANOVA for analysis of response to rhTNF-α exposure and Sidak's multiple comparison between GE-Prim and GE-TERT. ELISA, enzyme-linked immunosorbent assay.