MANα1-2MAN decorated liposomes enhance the immunogenicity induced by a
DNA vaccine against BoHV-1
Abstract
New technologies in the field of vaccinology arise as necessity for
treatment and control of many diseases. Currently modified live virus
and inactivated vaccines used for Bovine Herpesvirus-1 (BoHV-1) have
several disadvantages. Previous works for preventive treatment of BoHV-1
with DNA based vaccines have demonstrated the capability to induce
humoral and cellular immune response. Nevertheless, it is well known
that “naked” DNA induces low immunogenic response. Thus, loading of
antigen encoding DNA sequences in liposomal formulations targeting
dendritic cell receptors could be a promising strategy to better
activate these antigen presenting cells (APC). In this work, DNA based
vaccine encoding the truncated version of gD glycoprotein (pCIgD) of
BoHV-1 was investigated alone and upon encapsulation on liposomal
formulation coated with MANα1-2MAN-PEG-DOPE and LPS from Brucella ovis
(pCIgD-Man-L) in mice and cattle assay. Results showed that the use of
pCIgD-Man-L was capable to enhance the immune response in both animal
models. Significant levels of humoral immunity were achieved when total
antibody titers and isotypes were detected in sera and mucosa. For
cellular immunity, specific viral lymphoproliferation was detected in
the animals inoculated with pCIgD-Man-L. In addition, positively
modulation of CD40 molecules on the surface of bovine dendritic cells
(DCs) was observed when cells were stimulated and activated with vaccine
formulations. When challenge assay was performed, bovines inoculated
with pCIgD and liposome decorated with MANα1-2MAN-PEG-DOPE elicited
better protection and diminished viral excretion. The results
demonstrate the targeting of the MANα1-2MAN coated liposomes toward
dendritic cells and their ability to boost the immunogenicity according
to an adjuvant effect that results in long-lasting immunity. Liposome
decorated with MANα1-2MAN-PEG-DOPE were for the first time tested as DNA
based vaccine in cattle as preventive treatment of BoHV-1. These results
open up new perspectives for the design of vaccine for the control of
bovine rhinotracheitis.