A Prime/Boost PfCS14K M /MVA-sPfCS M Vaccination Protocol Generates Robust CD8 + T Cell and Antibody Responses to Plasmodium falciparum Circumsporozoite Protein and Protects Mice against Malaria

• Published in: Clinical and vaccine immunology Vol. 24; no. 5
• Main Authors: Vijayan, Aneesh, Mejías-Pérez, Ernesto, Espinosa, Diego A, Raman, Suresh C, Sorzano, Carlos Oscar S, Zavala, Fidel, Esteban, Mariano
• Format: Journal Article
• Language: English
• Published: United States 01.05.2017
• Subjects: Animals; Antibodies, Protozoan - immunology; CD8-Positive T-Lymphocytes - immunology; Malaria Vaccines - immunology; Malaria, Falciparum - immunology; Malaria, Falciparum - prevention & control; Mice; Protozoan Proteins - immunology; Vaccines, DNA - immunology; oligomeric PfCS; polyfunctional CD8+ T cells; MVA-PfCS; antibodies; transgenic P. berghei; malaria vaccine; P. falciparum circumsporozoite
• ISSN: 1556-6811; 1556-679X
• DOI: 10.1128/CVI.00494-16

Vaccines against the preerythrocytic stages of malaria are appealing because the parasite can be eliminated before disease onset and because they offer the unique possibility of targeting the parasite with both antibodies and T cells. Although the role of CD8 T cells in preerythrocytic malaria stages is well documented, a highly effective T cell-inducing vaccine remains to be advanced. Here we report the development of a prime-boost immunization regimen with the circumsporozoite protein (PfCS) fused to the oligomer-forming vaccinia virus A27 protein and a modified vaccinia virus Ankara (MVA) vector expressing PfCS. This protocol induced polyfunctional CD8 T cells with an effector memory phenotype and high PfCS antibody levels. These immune responses correlated with inhibition of liver-stage parasitemia in 80% and sterile protection in 40% of mice challenged with a transgenic parasite line that expressed PfCS. Our findings underscore the potential of T and B cell immunization strategies for improving protective effectiveness against malaria.