Evaluation of the Immune Response of a Candidate Phage-Based Vaccine against Rhipicephalus microplus (Cattle Tick)

Abstract

Cattle tick (Rhipicephalus microplus) represents a severe problem causing substantial economic losses, estimated in billions of dollars annually. Currently, chemical acaricides represent the most widely used control method. However, several problems such as resistance have been described. Phage-based vaccines represent a fast and low-cost tool for antigen delivery. In this regard, the objective of the present work was to develop a candidate phage-based vaccine displaying a cattle tick antigen (Bm86-derived Sbm7462 antigen) on the surface of bacteriophage M13. Phage ELISA and dot blotting analysis confirmed the display of the antigen. Vaccine immunogenicity was evaluated using a bovine monocyte-derived dendritic cell-based ex vivo assay and a murine in vivo assay. The ex vivo model showed the maturation of dendritic cells after being pulsed with the phage-based vaccine. The humoral response was confirmed in the in vivo assay. These results demonstrated the capacity of the phage-based vaccine to induce both humoral and cellular immune-specific responses. Importantly, this is the first report describing a control method for cattle ticks using a candidate phage-based vaccine. Further studies to evaluate the immunogenicity in a bovine model are needed. The current approach represents a promising alternative to control cattle tick infestations.

Aspects of Phage-Based Vaccines for Protein and Epitope Immunization

“…The suggested vaccination generated a similar immunological response as the currently available Bm86-based vaccine. Although the ex vivo assay provides a broad picture of the vaccine’s effects, a bovine in vivo experiment is still required to establish the vaccine’s efficacy [ 41 ].…”

Genetically engineered bacteriophages as novel nanomaterials: applications beyond antimicrobial agents

“…Genetically engineered M13 phages have the potential to induce immune response in susceptible individuals due to their proteins or modified amino acids. Moreover, the repetitive structures of their coat proteins have been shown to possibly trigger immune responses ( González-Mora et al, 2021 ; Venturini et al, 2022 ). Although the replication and production of M13 phages do not entail bacterial cell disruption, they are synthesized within E. coli cells.…”