New immune targets pave the way for more effective malaria vaccines

Researchers led by Dr. Caroline Junqueira at the Institute for Research in Biomedicine (IRB), Bellinzona affiliated with Università della Svizzera italiana (Usi), have identified a new set of malaria parasite antigens that could support the development of broader vaccines against the disease. Published in Nature, the study maps the protein fragments displayed by Plasmodium-infected cells and recognized by CD8+ T cells, immune cells able to identify and eliminate infected cells.

Using immunopeptidomics, which combines immunology and proteomics to define the antigens presented to the immune system, the team identified 453 peptides derived from 166 parasite proteins. Many of these targets come from housekeeping proteins, essential components that are conserved across different Plasmodium species and liver and blood stages of the parasite life cycle.

The identified antigens triggered immune responses in samples from people infected with P. vivax and P. falciparum, as well as in experimental models involving additional Plasmodium species. Some targets also showed evidence of protection in animal models, reducing parasite load.

While currently available malaria vaccines provide partial and time-limited protection, mainly against P. falciparum and early infection at the liver, this work points to targets that may act across liver and blood stages of the infection and across species. By revealing conserved CD8+ T-cell antigens, the study provides a valuable basis for future vaccine strategies aimed at broader and more durable protection.