Ivan Kairatov is a leading biopharma expert specializing in the research and development of next-generation immunotherapies. With a deep background in genetic engineering and tumor immunology, he has focused his career on solving the spatial and metabolic challenges that prevent modern medicine from eradicating solid tumors. His recent work explores the intersection of cancer metabolism and cell migration, seeking to transform the way we engineer immune cells to navigate the complex landscape of the human body.
The following discussion explores the limitations of traditional CAR-T therapies in solid tumors, the discovery of metabolite-sensing receptors, and the revolutionary “breadcrumb trail” approach that allows immune cells to hunt down aggressive cancers by following their unique chemical signatures.
While CAR-T therapy excels in blood cancers, solid tumors often present spatial barriers and T cell exhaustion. How do you visualize the physical journey of an immune cell into a dense tumor, and what specific mechanical or signaling hurdles must it overcome to remain functional upon arrival?
When we visualize the journey of an immune cell, we have to look past the bloodstream and into the dense, hostile architecture of a solid tumor. In blood cancers, targets are easily accessible, but in solid tumors like breast or ovarian cancer, the primary hurdle is actually getting the cells to show up at the right “address” in sufficient numbers. We often see that even the most potent CAR-T cells become exhausted because they are prone to excessive signaling before they even penetrate the tumor mass. Physically, these cells must navigate a crowded extracellular space where too few T cells currently manage to infiltrate, leaving the cancer’s interior virtually untouched. By the time a traditional immune cell arrives, it is often too “tired” to function, which is why we are shifting our focus from just killing capacity to the spatial mechanics of migration and infiltration.
Moving beyond surface proteins, focusing on metabolic byproducts like phospholipids or cholesterol derivatives creates a “breadcrumb trail” for immune cells. Could you explain the step-by-step process of how receptors detect these small molecules, and what metrics indicate the cells are navigating this trail successfully?
The process begins with the cancer cell’s “headlong dash” to proliferate, which creates a unique metabolic signature consisting of small molecules, fats, and ions like oxidized cholesterol derivatives or phospholipids. Unlike proteins tethered to a cell surface, these metabolites diffuse into the spaces between cells, creating a gradient that functions like a “yellow brick road” where the path becomes clearer and wider as the immune cell gets closer to the source. We engineer immune cells with G-protein coupled receptors (GPCRs) that act as highly sensitive sensors for these specific bioactive metabolites. We know the cells are navigating successfully when we observe a marked increase in infiltration—in our studies, equipping cells with these receptors allowed them to sense the tumor, migrate specifically toward it, and accumulate within the dense tissue rather than just circulating aimlessly in the blood.
Identifying the most effective genes for tumor infiltration involves complex genetic screening and competitive testing in animal models. What does a high-performing gene look like in these competitive environments, and what laboratory observations highlight the unique behavior of immune cells equipped with G-protein coupled receptors?
To find these “winners,” we screened 256 candidate genes and used CRISPR to activate them individually in human natural killer (NK) cells, then let them compete against one another in mice bearing human tumors. A high-performing gene, such as those we’ve labeled “tumor-homing GPRs” or thGPRs, stands out because it consistently drives superior migration across different model systems and experimental settings. The most striking observation was that traditional chemokine receptors weren’t the top performers; instead, the cells that dominated the competition were those equipped to recognize metabolic byproducts of aggressive growth. In the lab, we see these engineered cells actively tracking the “smoking gun” of cancer metabolism, showing a directional persistence that ordinary immune cells simply lack.
Engineering cells with receptors like GPR183 has demonstrated a significant increase in complete response rates for aggressive breast and ovarian cancers. What are the long-term survival implications when tumors are eradicated this way, and how do you manage the risk of cells attacking healthy tissues?
The long-term implications are profound, as we observed a doubling in the number of complete responses in animal models, with highly aggressive breast tumors being eradicated so thoroughly that they did not return. When tumors are eliminated through this metabolite-sensing mechanism, the mice returned to a state of health that suggests a very durable therapeutic effect. Regarding safety, one of the biggest challenges in immunotherapy is that many protein targets are also found on normal tissue, leading to “off-target” attacks. However, by targeting the unique metabolic byproducts of uncontrolled proliferation—features so distinct they are used for PET imaging—we are tapping into a signature that is inherently linked to the cancer’s aggressive nature, which helps the immune cells distinguish the tumor from healthy, metabolically stable tissues.
There is significant interest in turning metabolic cues into “on-switches” that activate immune cell killing potential only within the tumor microenvironment. How would you design a clinical trial to test this localized activation, and what are the primary safety benchmarks required for human testing?
Designing a clinical trial for localized activation would involve testing the GPR183-engineered cells specifically in patients with solid tumors that have shown resistance to standard therapies. We are currently moving toward human testing where the primary safety benchmarks will focus on ensuring these “on-switches” only trigger the cells’ “killing machine” mode once they have sensed the specific metabolite concentrations found within the tumor. This layer of control is vital; we want the cells to be “homing” during their journey and “killing” only upon arrival. We would monitor the patients for any signs of systemic inflammatory responses, ensuring that the enhanced infiltration we saw in our mice models translates to a safe, localized attack in humans without damaging vital organs.
What is your forecast for the future of metabolite-sensing immunotherapy?
I believe we are entering an era where we will no longer view cancer’s aggressive metabolism solely as a driver of drug resistance, but as its greatest vulnerability. My forecast is that within the next decade, metabolite-sensing will become a standard component of cell engineering, allowing us to create “smart” therapies that interpret the tumor microenvironment as a set of navigational cues and activation signals. We will likely move beyond the six thGPRs we’ve identified to a broader library of receptors, potentially even modifying them to recognize metabolites that aren’t naturally chemoattracting. This approach will finally bridge the gap between the success we’ve seen in blood cancers and the difficult-to-treat landscape of solid tumors, turning the very hallmarks of cancer growth into the tools for its own destruction.
