Study reveals how the immune system builds its own defenses, a discovery that could lead to more effective cancer immunotherapies
Scientists at the Icahn School of Medicine at Mount Sinai have discovered which immune cell functions as the architect of powerful immune structures that develop within tumors, playing a critical role in fighting cancer. The research, appearing in Science on July 16, could advance cancer immunotherapy strategies.
The study identifies dendritic cell type 1 as essential for constructing and sustaining tertiary lymphoid structures (TLSs)—organized immune cell clusters that function as localized command centers where the body mounts direct attacks against cancer within tumors.
Previous studies demonstrated that patients whose tumors contain TLSs often experience improved survival and better immunotherapy responses. Scientists previously lacked understanding of what drives formation and maintenance of these protective immune structures.
Lead researcher Raphael Mattiuz stated: “Our goal was to understand how these immune structures develop and persist inside tumors.” He explained that the team discovered “a distinct subset of dendritic cells acts as the organizer” bringing different immune cells together.
The research team examined tumor samples from patients with lung, liver, colorectal, kidney, and ovarian cancers using advanced imaging and spatial gene analysis. They created a mouse model reflecting human tertiary lymphoid structures, then selectively removed or altered dendritic cells at different tumor development stages.
Results demonstrated that dendritic cells establish these immune hubs and sustain their function over time. Rather than merely alerting the immune system, these cells remain within tumors as permanent coordinators, bringing together cancer-fighting T cells and antibody-producing B cells.
“We were surprised to see that these rare cells become permanent organizers within the tumor itself,” Mattiuz noted.
Senior researcher Miriam Merad stated: “This study provides a foundation for developing treatments that strengthen the body’s own immune defenses against cancer.”
The findings suggest potential therapies designed to increase dendritic cell numbers or activity could strengthen immune hubs and potentially improve existing immunotherapies, particularly for patients with treatment-resistant cancers.
Researchers plan investigating how TLSs generate durable immune protection and whether dendritic cell-activating therapies can enhance immunotherapy outcomes and prevent cancer recurrence.
Journal: Science
DOI: 10.1126/science.ady1678
Article Title: Dendritic cells control tertiary lymphoid structure development and maintenance in cancer
Publication Date: July 16, 2026
Source: EurekAlert