By Pesach Benson • June 14, 2026
Jerusalem, 14 June, 2026 (TPS-IL) — Israeli scientists have identified a previously unrecognized form of immune memory that may help the body target cancer cells and could open new paths toward cancer vaccines.
A recent study from the Weizmann Institute of Science found that cancer may not be as invisible to the immune system as once believed, suggesting that memory B cells, long known for protecting against infections, can also mount a targeted response against malignant tumors.
The findings, published in the peer-reviewed journal Immunity, challenge long-held assumptions and open new avenues for developing cancer vaccines.
The immune system relies on B cells to produce antibodies, proteins that recognize and help neutralize threats such as viruses and bacteria. When a B cell first encounters a target, it undergoes a refinement process in lymph nodes, where it improves the precision of its antibodies. Some of these cells become long-lived memory B cells that remain stored in lymph nodes, ready to respond rapidly if the threat returns. However, because tumors arise from the body’s own tissues, it was unclear whether such immune memory could also form against cancer.
The Israeli Study, led by researchers in Prof. Ziv Shulman’s laboratory, examined tumor samples and nearby lymph nodes from 11 patients with high-grade serous ovarian cancer, the most common and aggressive form of the disease.
To their surprise, the researchers found that most B cells in lymph nodes near tumors were memory B cells. Further analysis showed that some of these cells were closely related to B cells found inside tumors themselves, suggesting they were migrating from lymph nodes into cancerous tissue and continuing their activity there.
Putting Immune Memory to the Test
The team then isolated the genetic blueprints of these antibodies and reproduced them in the laboratory to test their function. More than a third of the engineered antibodies bound strongly to ovarian cancer cells, while showing far weaker binding to healthy human cells.
“We feared that the antibodies would attack human cells indiscriminately, but in fact they turned out to be a targeted weapon against ovarian cancer,” Shulman said.
The researchers believe this selectivity is important, as it suggests the immune system can distinguish cancer cells from normal tissue despite their shared biological origin. Dr. Nahum Nathan, who led the study, explained that the findings indicate these memory B cells are not passive reserves but active participants in the immune response, capable of moving between lymph nodes and tumors and adapting as they go.
The study also uncovered an unexpected obstacle. In lymph nodes near tumors, immune activity appeared to be suppressed by macrophages, a type of immune cell that removes other cells during inflammation. Using live imaging, the researchers observed macrophages engulfing B cells during their training stages, effectively limiting the formation of new immune memory.
This suppression may help explain why cancer can persist despite an immune response. It also raises the possibility that modifying these regulatory cells could enhance the body’s natural defenses.
Importantly, some of the identified antibodies targeted a key protein involved in cancer growth and spread, suggesting that tumors may find it difficult to evade such responses through mutation alone.
Researchers also noted that similar immune suppression mechanisms may occur in other diseases, including inflammatory bowel conditions, where overly suppressive macrophages can reduce beneficial immune activity.
The study points to several practical applications, mostly still in early-stage research.
If memory B cells can be reliably trained to recognize tumor-specific targets, they could be harnessed to teach the immune system to recognize cancer earlier or respond more aggressively after treatment.
Another application is antibody-based therapies. Since the researchers successfully isolated and reproduced antibodies from these memory B cells, those antibodies could potentially be developed into targeted drugs.
Finally, the research opens the door to immune system reprogramming. If scientists can better control the suppressive macrophages that limit B cell activation in lymph nodes, it may be possible to boost the body’s natural ability to generate anti-cancer memory—or, conversely, dampen immune memory in conditions where it becomes harmful, such as autoimmune disease.