Sustained-Release Leukemia Vaccine Developed

Researchers have developed a new type of precise therapeutic vaccine against leukemia. The collaborative team from the Institute of Process Engineering of the Chinese Academy of Sciences and Zhujiang Hospital of Southern Medical University published their results in Nature Biomedical Engineering.

"Our clinical findings revealed the high expression of EPS8 and PD-1/PD-L1 in leukemia patients, which could be respectively used as a new type of leukemia antigen and a checkpoint target for a leukemia vaccine," said lead researcher Li Yuhua.

In their vaccine, epitope peptides and PD-1 antibodies can be efficiently loaded into polylactic acid microcapsules, facilitated by the unique self-healing feature of the microcapsule. After a single vaccination, the deposition and degradation of microcapsules at the local injection site lead to the recruitment of activated antigen-presenting cells and sustained release of both cargos.

"With the synergism of these two aspects, we observed a significant improvement in specific Cytotoxic T Lymphocyte (CTL) activation," said researcher Wei Wei. The team also verified the availability of the vaccine using various epitope peptides in different models, such as murine leukemia, humanized cell line-derived leukemia xenograft (CDX), and patient-derived leukemia xenograft (PDX) models.

The microcapsule-based formulation demonstrated its superior performance over that of the commercialized adjuvant in all leukemia therapeutic models, showing the promise of the microcapsule-based vaccine for use against various leukemia antigens in the clinic.

"With the advantages of FDA-approved polylactic acid material, convenience in preparing the vaccine formulation, diversity of vaccine components, and excellent therapeutic effect, the microcapsule-based vaccine exhibits great potential for clinical translation," said researcher Ma Guanghui.