The Rapid Evolution of Chronic Inflammation to Tolerance / Immune Suppression: Mapping Bidirectional Checkpoints

Currently, there is truly a universal lack of knowledge as to exactly how chronic inflammation leads to the initiation of cancer. Likewise, there exists an equal deficiency in knowledge to define the phenomenon of immune “ tolerance”. Tolerance is, however, generally described as the diminished biological response to repeated or sustained antigen exposure associated with limitation to efficacy of toll-like receptor (TLR) synthetic lipid A lipoglycans, or microbial antigen molecular pattern (MAMP) based tumor immune therapies. The current work was designed to gain greater understanding into these questions, by employing a model of sustained antigenic TLR4 activation with gram-negative cell wall (LPS) for up to 11 days in macrophages under highly controlled conditions. Raw 264.7 macrophages were treated with 500ng/ml for up to 11 days. Phenotype evolution was monitored by WT RNA sequencing & protein spot check for: baseline (resting), 1-day LPS (acute), 7- & 11-day LPS (sustained chronic).Long term chronic inflammation required 18 hour periodic treatment changes, high volume/cell density ratio to ensure removal of cellular by-products that could create interfering (false) artifacts.