Researchers from the Institute of Process Engineering (IPE) of Chinese Academy of Sciences and Zhujiang Hospital of Southern Medical University have developed a new precise therapeutic vaccine against leukaemia by co-encapsulated a new epitope peptide and PD-1 antibody using polylactic acid (PLA) microcapsules.
“Our clinical findings revealed the high expression of EPS8 and PD-1/PD-L1 in leukaemia patients, which could be respectively used as a new type of leukaemia antigen and a checkpoint target for a leukaemia vaccine,” said Prof. Li Yuhua from Zhujiang Hospital.
After a single vaccination, the deposition and degradation of the self-healing PLA 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 Prof. WEI Wei from IPE. The researchers also verified the availability of the novel vaccine using various epitope peptides in different models, such as murine leukaemia, humanised cell line-derived leukaemia xenograft (CDX) and patient-derived leukaemia xenograft (PDX) models.
The microcapsule-based formulation demonstrated its superior performance to that of the ISA adjuvant (commercialised adjuvant) in all leukaemia therapeutic models, showing the promise of the microcapsule-based vaccine for use against various leukaemia antigens in the clinic.
The study was published in Nature Biomedical Engineering.