How Scientists Are Learning to Block Chronic Inflammation Without Turning Off the Body's Defenses

For years, if you wanted to suppress IL-6, you had a blunt instrument. Drugs like tocilizumab and sarilumab block the IL-6 receptor entirely, shutting down everything the molecule does. They are effective medicines for rheumatoid arthritis and some other autoimmune conditions, but they also raise the risk of serious infections because they suppress protective immunity alongside the disease-driving inflammation. This trade-off has always been the central dilemma in IL-6 biology: IL-6 is both part of the problem and part of the solution.

A paper published this month in Nature Reviews Drug Discovery, covered by Medical Xpress, describes how researchers are now solving that dilemma. The key insight, which has been building in the scientific literature for more than a decade but is now reaching clinical maturity, is that IL-6 does not signal in a single way. It signals through two distinct pathways, only one of which is primarily responsible for pathological, chronic inflammation. The other pathway is largely protective. By blocking just the first one, it is theoretically possible to quiet disease without suppressing defense, and the clinical data is beginning to validate that theory.

What Is IL-6 and Why Does It Show Up in Everything?

IL-6 is often described as a cytokine with an extraordinary range of effects, and that description is accurate but also a little misleading. The reason it appears in so many diseases, from rheumatoid arthritis and inflammatory bowel disease to heart disease, cancer, and depression, is not simply that IL-6 is a general troublemaker. It is that IL-6 is genuinely involved in both the initiation and the regulation of inflammatory responses across virtually every tissue system in the body. When the body mounts an immune response, IL-6 is typically one of the first cytokines released. It travels to the liver and triggers the production of acute-phase proteins including CRP and fibrinogen. It activates immune cells. It modulates how other inflammatory signals are processed.

In a healthy, short-term inflammatory response, this is exactly what the body needs. A cut gets infected, IL-6 rises, CRP rises, the immune system mobilizes, the infection is cleared, and everything returns to baseline. The problem is when this cascade does not resolve. In chronic inflammatory disease, IL-6 keeps signaling. CRP stays elevated. Immune cells remain activated. Tissues sustain damage over months and years rather than healing. This is what shows up as persistently elevated high-sensitivity CRP (hsCRP) in blood or saliva, the kind of quiet, smoldering inflammation that is increasingly recognized as a driver of cardiovascular disease, metabolic disease, and accelerated biological aging.

The Two Faces of IL-6: Classic Signaling vs. Trans-Signaling

The breakthrough in understanding IL-6 came when researchers realized it does not have just one way of reaching cells. In what is called classic signaling, IL-6 binds to its membrane-bound receptor (called IL-6R or gp80) on the cell surface. The problem is that very few cell types actually carry this receptor: mainly hepatocytes (liver cells), some immune cells, and a limited number of others. Classic signaling is the mode through which IL-6 performs many of its protective, acute-phase functions, including driving CRP production in the liver and helping neutrophils and other immune cells do their jobs during infection.

Trans-signaling is a fundamentally different mechanism, and it is the one that drives the chronic, disease-promoting side of IL-6 biology. In trans-signaling, IL-6 first binds to a soluble, circulating version of its receptor (called sIL-6R) that floats freely in the bloodstream. The resulting IL-6 and sIL-6R complex can then bind to a second protein, called gp130, which is present on the surface of almost every cell in the human body. Because virtually every cell type carries gp130, trans-signaling gives IL-6 access to tissues it could not reach via classic signaling alone: endothelial cells, smooth muscle cells, neurons, fat cells, and intestinal epithelial cells, among others. This is the pathway that perpetuates inflammation in rheumatoid arthritis, maintains the chronic mucosal inflammation of Crohn's disease and ulcerative colitis, contributes to atherosclerosis, and appears to be involved in the neuroinflammation seen in depression and cognitive decline.

The distinction matters enormously for treatment. If trans-signaling is the primary disease driver, then a drug that only blocks trans-signaling could theoretically quiet chronic inflammation without touching the protective classic signaling pathway. You would not be suppressing the immune system broadly. You would be removing the disease amplifier while leaving the immune defenses intact. That is exactly what olamkicept was designed to do.

What Olamkicept Does and How It Works

Olamkicept (also known by its molecular name sgp130Fc) is a designer decoy protein rather than a conventional antibody. It consists of the extracellular portion of gp130, the shared receptor subunit, fused to an antibody fragment that extends its half-life in the bloodstream. When the IL-6 and sIL-6R complex forms, olamkicept intercepts it before it can bind to cell-surface gp130. Because it only captures the IL-6/sIL-6R complex (the trans-signaling intermediate), it does not interfere with IL-6 binding to its membrane-bound receptor on cells that carry classic signaling. The result is selective, pathway-specific blockade of the disease-promoting arm while classic signaling continues unimpeded.

This specificity was confirmed in clinical studies. According to PubMed, a phase 2a open-label trial (the FUTURE trial, published in Gastroenterology) treated 16 patients with active inflammatory bowel disease with olamkicept over 12 weeks. Olamkicept was well tolerated, induced clinical response in 44 percent of patients, and achieved remission in 19 percent. Critically, molecular profiling showed that olamkicept produced a distinct transcriptional signature in the inflamed intestinal mucosa, different from those produced by anti-TNF or anti-integrin therapies, without signs of immunosuppression (Schreiber et al., Gastroenterology, 2021). Patients did not develop the elevated infection risk that is the principal concern with broad IL-6 receptor blockade.

Subsequent randomized controlled trials have produced more compelling numbers. In a larger phase 2 randomized trial in ulcerative colitis, olamkicept achieved a clinical response rate of 58.6 percent compared with 34.5 percent for placebo, again without the adverse effects associated with broader IL-6 blockade. Phase 3 testing is now planned. The Nature Reviews Drug Discovery review published this month calls this evidence that a signal-mode-selective approach to IL-6 inhibition is feasible and clinically meaningful, a conceptual step forward not just for IBD but potentially for every inflammatory disease where trans-signaling plays a dominant role.

Where Trans-Signaling Fits in the Wider Landscape of Chronic Disease

The significance of the trans-signaling discovery extends well beyond inflammatory bowel disease. Sustained IL-6 trans-signaling has been implicated in the development and progression of a wide range of conditions. In cardiovascular disease, trans-signaling promotes endothelial dysfunction, the first step in the development of atherosclerosis, by activating gp130 on vascular endothelial cells that do not express the membrane-bound IL-6R. In metabolic disease, trans-signaling in adipose and hepatic tissue appears to contribute to insulin resistance and fatty liver. In the brain, trans-signaling may drive the neuroinflammation linked to depression and Alzheimer's disease.

A 2026 review in Immunopharmacology and Immunotoxicology also identified IL-6 trans-signaling as a contributor to deep vein thrombosis. Based on articles retrieved from PubMed, the review found that sustained trans-signaling contributes to endothelial dysfunction, hypercoagulability, and thrombus formation, with selective inhibition of trans-signaling appearing particularly promising as it suppresses pathological inflammation while preserving the protective effects of classical IL-6 signaling (Prasannan et al., Immunopharmacol Immunotoxicol, 2026). This cross-disease relevance helps explain why the pharmaceutical industry's interest in selective IL-6 targeting is accelerating.

At the same time, it is worth being precise about what this research does and does not say. Selective trans-signaling blockade is a pharmaceutical intervention currently in clinical trials. The findings so far tell us a great deal about the molecular architecture of chronic inflammation but they do not translate into a recommendation to take a particular supplement or eat a particular food. What the research does reinforce is that chronic, systemic IL-6 activity and the CRP elevation that reflects it represent a genuine mechanism of tissue damage over time, not merely a statistical association.

What This Means for CRP as a Wellness Marker

The trans-signaling story adds a layer of nuance to why CRP is such a useful marker for monitoring general wellness. When you measure hsCRP, whether in blood or in saliva, you are not measuring inflammation in a simple, direct way. You are measuring the liver's response to sustained IL-6 signaling. That response is the liver's way of announcing that the immune system has been receiving persistent activation signals, that somewhere in the body, inflammatory pathways are active at a level that warrants a systemic acute-phase response.

The research on trans-signaling helps clarify which kind of IL-6 activity you most want to avoid sustaining. Classic signaling, the short-burst response to infection or acute injury, produces a temporary CRP spike that resolves once the trigger is cleared. Trans-signaling, driven by the circulating IL-6 and sIL-6R complex that can reach virtually every tissue, produces the kind of low-grade, persistent CRP elevation that epidemiological studies have consistently linked to elevated risk of heart disease, metabolic syndrome, and cognitive decline. An hsCRP value that stays elevated over months, rather than spiking and returning to baseline, is the signature of trans-signaling dominance. That is what you are tracking when you measure CRP repeatedly over time.

Lifestyle factors that lower CRP tend to reduce the inputs that drive trans-signaling, even if they are not targeting the pathway explicitly. Regular physical activity reduces visceral adiposity, one of the main sources of sIL-6R production. An anti-inflammatory diet reduces the oxidative stress and gut permeability that amplify IL-6 release. Adequate sleep allows the body's natural inflammatory resolution mechanisms to operate. None of these is as potent as a pharmaceutical IL-6 inhibitor, but they work through the same biological system. They reduce the pool of circulating IL-6 and sIL-6R available to form the trans-signaling complex, and CRP falls as a result.

Tracking CRP over time gives you a window into whether those lifestyle changes are working at the level of the underlying biology. A person who improves their sleep, reduces ultra-processed food intake, and starts exercising consistently can expect to see hsCRP trend downward over weeks to months, even if no single change produces a dramatic drop. That trajectory is meaningful information. It tells you that the inflammatory load your body is carrying is decreasing. The research on IL-6 trans-signaling gives you a mechanistic story for why: your cells are being exposed to less of the circulating IL-6/sIL-6R complex that drives chronic tissue damage, and the liver's alarm signal, CRP, is quieting in response. CRP is a general wellness marker, and persistent elevations are always worth discussing with a healthcare provider, but trends over time tell a story that single snapshots cannot.

Sources

• Rose-John S, et al. Refining therapeutic targeting of interleukin-6 by signalling mode selectivity. Nature Reviews Drug Discovery, September 2026. nature.com/articles/s41573-026-01536-x (via Medical Xpress coverage)
• Schreiber S, Aden K, Bernardes JP, et al. Therapeutic Interleukin-6 Trans-signaling Inhibition by Olamkicept (sgp130Fc) in Patients With Active Inflammatory Bowel Disease. Gastroenterology, 2021. doi.org/10.1053/j.gastro.2021.02.062
• Prasannan A, Venkatachalam K, Joy S, et al. Could IL-6 inhibitors be the future of DVT therapy? A new era in therapeutic strategies. Immunopharmacology and Immunotoxicology, 2026. doi.org/10.1080/08923973.2025.2608137
• Zhang LB, Qiu XY, Zhou YH, et al. Recombinant Sgp130 attenuates alkali-burn cornea through inhibition of IL-6 trans-signaling. International Journal of Biological Macromolecules, 2026. doi.org/10.1016/j.ijbiomac.2026.153509
• I-Mab. Positive Topline Phase 2 Results for Olamkicept in Ulcerative Colitis. BioSpace. biospace.com

Frequently Asked Questions

What is IL-6 trans-signaling, and why does it matter for inflammation?

IL-6 trans-signaling is the process by which interleukin-6 binds to a soluble, circulating version of its receptor (sIL-6R) and then activates a second receptor protein called gp130, which is present on virtually every cell in the body. Because trans-signaling can reach cell types that the standard IL-6 receptor cannot, it is the mechanism most responsible for spreading and sustaining chronic, systemic inflammation. Classic IL-6 signaling, which occurs through the membrane-bound receptor on a limited set of cells, is largely protective. The distinction means that blocking only trans-signaling could suppress disease without suppressing immune defense.

What is olamkicept and how is it different from other IL-6 blockers?

Olamkicept (sgp130Fc) is an experimental drug designed to selectively block IL-6 trans-signaling without affecting classic IL-6 signaling. It works by acting as a decoy protein that intercepts the IL-6 and soluble IL-6R complex before it can bind to cell-surface gp130. Existing broad IL-6 blockers like tocilizumab shut down both signaling modes, which effectively suppresses inflammation but also raises infection risk by impairing protective immune functions. Olamkicept's selectivity is designed to avoid that trade-off. Phase 2 randomized controlled trial results in ulcerative colitis show a 58.6 percent clinical response rate versus 34.5 percent for placebo, without the immune suppression seen with broader IL-6 inhibition.

How does CRP reflect IL-6 signaling?

CRP (C-reactive protein) is produced by the liver in direct response to IL-6 signaling. When IL-6 levels rise, the liver increases CRP production as part of the acute-phase inflammatory response. A persistently elevated hsCRP reading reflects ongoing IL-6 activity, which research now suggests is driven largely by trans-signaling. Tracking CRP over time gives a picture of whether the overall inflammatory load the body is carrying is increasing or decreasing. Acute spikes from illness or injury are normal and expected; a trend of elevated CRP over weeks or months is the signal worth paying attention to and discussing with a healthcare provider.

Can lifestyle changes lower IL-6 trans-signaling?

No direct test for trans-signaling is available outside research settings, but CRP and IL-6 blood levels both fall in response to lifestyle changes that reduce the drivers of chronic inflammation. Regular moderate exercise, an anti-inflammatory diet rich in vegetables and omega-3 fatty acids, adequate sleep, and reducing visceral body fat all lower circulating IL-6 and CRP. These changes reduce the pool of IL-6 and soluble IL-6R available to form the trans-signaling complex, which is the pathway most responsible for perpetuating chronic inflammatory disease. CRP monitoring over time can reflect whether those changes are working at the level of actual biology.