Elastic liposomes mediated delivery of chimeric fusion protein (PfMSP-Fu24) provokes heightened immune response against P. falciparum

Abstract

P. falciparum malaria is one of the most devastating vector-borne diseases and is accountable for a high global death rate. Development of efficacious vaccines to eliminate the infection is a major challenge, mainly due to lack of well-defined correlates of immunity for protection, evolution and diversification of drug-resistant parasite strains, and the tortuous life cycle of the parasite inside the human host. During the erythrocytic stage of the life cycle, the reactions occurring at the merozoite-RBC interface is responsible for the clinical symptoms of malaria. Hence, proteins expressed during these reactions (MSPs) are considered as potential targets for novel vaccines. Considering that the combination of antigens is more powerful a vaccine than a single antigen, a chimeric fusion protein (PfMSP-Fu24) was formulated, comprising of two potential candidate antigens, MSP-119 and MSP-311. Encapsulation of this protein in certain vaccine delivery vectors, such as nanocarriers, guarantees uptake by the respective cells while protecting the protein from degradation. Biocompatible nanocarriers, with their size less than 200nm, render least toxicity and can overcome challenges posed by traditional delivery vehicles. Among these biocompatible nanocarriers, elastic liposomes (ELs) have recently proven to be the most efficient due to their ultra-deformability and permeability, rendered by their cell-membrane lipid bilayer composition. Entrapment of the fusion protein in these ELs (EL-PfMSP-Fu24) can, therefore, be one of the many futuristic approaches to obtain sterile immunity against the parasite by obstructing invasion of erythrocytes, thereby blocking transmission of malaria.