Background
Hepatocellular carcinoma-associated antigen 59 (HCA59) from excretory/secretory products of
Haemonchus contortus
is known to have the ability to modulate the functions of host cells. However, its immunogenicities using different nanoparticles adjuvants remain poorly understood.
Purpose
The study aimed to select an efficient nanoparticle antigen delivery system, which could enhance the immune responses of
Haemonchus contortus
HCA59 in mice.
Methods
Here, the immune responses induced by the recombinant protein of HCA59 (rHCA59) with poly-D,L-lactide-co-glycolide (PLGA) nanoparticles, Chitosan nanoparticles, mixture of PLGA and Chitosan nanoparticles (rHCA59-Chitosan-PLGA), and Freund’s complete adjuvant were observed, respectively, in mice. Cytokine and antibody levels induced by different groups were detected by ELISA assay. The effects of lymphocyte proliferations on different groups were examined using CCK-8 kit. Phenotypes of T cells and dendritic cells were analyzed by flow cytometry.
Results
On day 14 post vaccination, levels of IgM, IgG1, IgG2a, IFN-γ, IL-4, and IL-17 were significantly increased in the groups immunized with rHCA59 encapsulated with nanoparticles. After mice were vaccinated with rHCA59 loaded with Chitosan/PLGA nanoparticles, lymphocytes proliferated significantly. Additionally, the percentages of CD4
+
T cells (CD3
+
CD4
+
), CD8
+
T cells (CD3
+
CD8
+
), and dendritic cells (CD11c
+
CD83
+
, CD11c
+
CD86
+
) were obviously up-regulated in the mice immunized with nanoparticles, especially in the rHCA59-Chitosan-PLGA antigen delivery system group.
Conclusion
The findings of this research demonstrated that rHCA59-Chitosan-PLGA antigen delivery system could induce higher immune responses in mice model and indicated that rHCA59 might be a good candidate molecule to develop nanovaccines against
Haemonchus contortus
in future study.