Red Blood Cell Particles Boost Cancer Vaccine Immunity in Mice

Researchers have shown that tiny particles derived from red blood cells can act as potent adjuvants for cancer vaccines, enhancing the cytotoxic T cell responses that current vaccine additives such as aluminum salts and emulsions often fail to provoke. The study, published in Nature Biomedical Engineering, describes how microparticles generated from erythrocytes by controlled ultraviolet irradiation skew immunity toward a T helper type 1 profile and strengthen tumour antigen-specific cytotoxic T cell activity both in vitro and across multiple mouse tumour models.

The team, led by Ke Tang and Bo Huang with colleagues at several institutions, found that when dendritic cells take up these erythrocyte-derived microparticles, the particles traffic to lysosomes and release a haem cargo that is subsequently transported into the nucleus. This intracellular delivery route proved central to the particles’ adjuvant effect.

Mechanistically, the microparticles raise lysosomal pH, which promotes the movement of lysosomes toward the nucleus and enables the transfer of haem to that compartment. Once inside the nucleus, haem activates the nuclear receptor REV-ERBα, which forms a co-repressor complex that suppresses peroxisome proliferator-activated receptor gamma, or PPARγ. Because PPARγ inhibits dendritic cell maturation and antigen presentation, its suppression relieves that inhibition, allowing dendritic cells to mature and present tumour antigens more effectively to T cells.

The published figures trace the evidence step by step: microparticles promoting dendritic cell maturation and antigen presentation; enhanced efficacy of dendritic cell vaccines in tumour models; haem as the critical cargo; REV-ERBα as the haem-responsive target; PPARγ as the downstream target in dendritic cells; and nuclear delivery of haem for REV-ERBα binding. A final schematic summarises how the particles drive dendritic cell maturation through this pathway.

Importantly, the adjuvant effect was not confined to mouse cells. In vaccination settings combining tumour antigens with the erythrocyte-derived particles, the researchers observed enhanced cytotoxic T cell activation and suppressed tumour growth with minimal toxicity. The study also reports that the particles exert an adjuvant effect on human dendritic cells, suggesting the mechanism may be conserved across species, although the therapeutic results reported are from mouse models rather than human trials.

The authors position these host-derived vesicles as a promising platform for next-generation cancer vaccine adjuvants, addressing the gap in adjuvants capable of inducing robust cytotoxic T cell immunity and T helper type 1 responses. Conventional adjuvants such as aluminum salts and emulsions are limited by weak induction of cytotoxic T cell immunity and restricted ability to promote T helper type 1 responses, the researchers note.

By showing that haem delivered from lysosomes can activate REV-ERBα and thereby lift PPARγ-mediated repression of dendritic cell maturation, the study links subcellular vesicle trafficking, nuclear receptor signalling, and antigen presentation in a single mechanistic chain.

As with any preclinical result, caveats apply. The antitumour effects were demonstrated in mouse tumour models and in vitro human dendritic cell experiments, and the full article is behind a paywall, so detailed dosing and safety margins cannot be assessed from the available abstract. Nevertheless, the work offers a concrete mechanistic rationale for turning an abundant, easily obtained cell type into a vaccine adjuvant, and it identifies the haem–REV-ERBα–PPARγ axis as a targetable node for future immunostimulatory design.

Subject of Research: Erythrocyte-derived microparticles as cancer vaccine adjuvants activating dendritic cells via haem and REV-ERBα signalling

Article Title: Autologous erythrocyte microparticles drive antitumour T cell immunity via haem-mediated dendritic cell activation

Article References: Tang, K., Liang, Y., Sun, W., Zheng, X., Lu, S., Chen, Z., Yan, Z., Liu, S., Liu, Y., Chen, Y., Deng, J., Zhang, H., Ma, J., Chen, J., Zhou, Y., Lv, J., & Huang, B. (2026). Autologous erythrocyte microparticles drive antitumour T cell immunity via haem-mediated dendritic cell activation. Nature Biomedical Engineering. https://doi.org/10.1038/s41551-026-01795-4

Image Credits: AI Generated

DOI: 10.1038/s41551-026-01795-4

Keywords: erythrocyte microparticles, cancer vaccine, adjuvant, dendritic cells, haem, REV-ERBα, PPARγ, cytotoxic T cells, lysosomes, antigen presentation, mouse models, immunotherapy