Potential of ferritin 2 as an antigen for the development of a universal vaccine for avian mites, poultry red mites, tropical fowl mites, and northern fowl mites

Abstract

IntroductionPoultry red mites (PRMs, Dermanyssus gallinae), blood-sucking ectoparasites, are a threat to the poultry industry because of reduced production caused by infestation. In addition, tropical fowl mites (TFMs, Ornithonyssus bursa) and northern fowl mites (NFMs, Ornithonyssus sylviarum) are hematophagous, distributed in various regions, genetically and morphologically close to PRMs, and cause similar problems to the poultry industry. Vaccine approaches have been studied for PRM control, and several molecules have been identified in PRMs as candidates for effective vaccine antigens. The development of an anti-PRM vaccine as a universal vaccine with broad efficacy against avian mites could improve the productivity of poultry farms worldwide. Molecules that are highly conserved among avian mites and have critical functions in the physiology and growth of mites could be ideal antigen candidates for the development of universal vaccines. Ferritin 2 (FER2), an iron-binding protein, is critical for the reproduction and survival of PRMs and has been reported as a useful vaccine antigen for the control of PRMs and a candidate for the universal vaccine antigen in some tick species.Method and resultsHerein, we identified and characterized FER2 in TFMs and NFM. Compared with the sequence of PRM, the ferroxidase centers of the heavy chain subunits were conserved in FER2 of TFMs and NFMs. Phylogenetic analysis revealed that FER2 belongs to clusters of secretory ferritins of mites and other arthropods. Recombinant FER2 (rFER2) proteins from PRMs, TFMs, and NFMs exhibited iron-binding abilities. Immunization with each rFER2 induced strong antibody responses in chickens, and each immune plasma cross-reacted with rFER2 from different mites. Moreover, mortality rates of PRMs fed with immune plasma against rFER2 from TFMs or NFMs, in addition to PRMs, were higher than those of control plasma.DiscussionrFER2 from each avian mite exhibited anti-PRM effects. This data suggests that it has the potential to be used as an antigen candidate for a universal vaccine against avian mites. Further studies are needed to access the usefulness of FER2 as a universal vaccine for the control of avian mites.

In Vivo Characterization of the Anti-Glutathione S-Transferase Antibody Using an In Vitro Mite Feeding Model

“…In addition, the application of homologous proteins present in different avian mites as vaccine antigens could be a valuable tool for the development of vaccines to control multiple avian mites. Recently, we reported that cysteine protease and ferritin 2 are highly conserved among avian mites, and that their application as vaccine antigens exhibits cross-protective immunity against avian mites [ 37 , 38 ]. In the present study, we characterized GSTs, which are important for the detoxification of acaricides in PRMs [ 54 ], and investigated their potential use as vaccine antigens against avian mites.…”

“…Recently, we reported the possible application of a single antigen as a universal vaccine for controlling avian mites [ 37 , 38 ]. This concept can encourage commercial production.…”

“…The total RNA from each mite species was extracted using the RNeasy RNA isolation kit (Qiagen, Germantown, MD, USA) according to the manufacturer’s protocol. One microgram of RNA was used to synthesize complementary DNA (cDNA) as previously described [ 37 , 38 ].…”

“…Blood-fed PRMs from each feeding group were collected with a Pasteur pipette 4 h after blood feeding. We previously demonstrated that a certain number of blood-fed PRMs could be obtained using this method [ 37 , 38 ]. The collected PRMs were maintained at 25 °C and 70% humidity to monitor their mortality.…”

“…To overcome these problems, alternative control approaches, including vaccines against PRMs, are being investigated [ 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 , 35 , 36 ]. Our research group targeted antigens with cross-protective efficacy against avian mites [ 37 , 38 ]. Thus, vaccines against avian mites may become a cost-effective strategy to control avian mites in the poultry industry.…”