Recruitment of RelB to the Csf2 promoter enhances RelA-mediated transcription of granulocyte-macrophage colony-stimulating factor.

ABSTRACT: Tumor necrosis factor (TNF) induces expression of granulocyte-macrophage colony-stimulating factor (GM-CSF) but lymphotoxin ? (LT?) does not. Here we report that priming of cells with agonistic LT? receptor antibody synergistically enhanced TNF-induced GM-CSF expression. The LT? priming process was not due to an increase in TNF-mediated nuclear translocation of p65, p65 DNA binding, or NF-?B transactivational activity. The synergistic effect of LT? priming was not observed with other TNF-responsive genes such as Ccl2 or RelB, which suggested that this effect was not a general increase in TNF signaling. Furthermore, RelB and p65 were both independently recruited to the GM-CSF promoter when cells were primed with LT? followed by TNF treatment. As a consequence, an increase in both chromatin accessibility and the recruitment of RNA polymerase II were observed to the GM-CSF promoter. Taken together, these findings suggested that LT? signaling amplified TNF-mediated GM-CSF expression by facilitating chromatin access and the co-recruitment of RNA polymerase II to increase gene transcription. Moreover, the novel priming process described here underscores the complexity of the interactions between the classical and alternative NF-?B signaling pathways.

SUBMITTER: Sasaki CY 

PROVIDER: S-EPMC3020716 | biostudies-literature | 2011 Jan

REPOSITORIES: biostudies-literature