Development of avian influenza virus H5 DNA vaccine and MDP-1 gene of Mycobacterium bovisas genetic adjuvant

Abstract

BackgroundStudies have shown that DNA vaccines can induce protective immunity, which demonstrated the high potential of DNA vaccines as an alternative to inactivated vaccines. Vaccines are frequently formulated with adjuvants to improve their release, delivery and presentation to the host immune system.MethodsThe H5 gene of H5N1 virus (A/Ck/Malaysia/5858/04) was cloned separately into pcDNA3.1 + vector. The immunogenicity of the cloned H5 DNA vaccine was tested on SPF chickens using two different approaches. First approach was using H5 DNA vaccine (pcDNA3.1/H5) and the second was using H5 DNA vaccine in addition to the pcDNA3.1/MDP1 vaccine. Ten days old chickens inoculated three times with two weeks intervals. The spleen and muscle samples from chickens immunized with H5 (pcDNA3.1/H5) and H5 + MDP1 (pcDNA3.1/H5 + pcDNA3.1/MDP1) vaccines were collected after sacrificing the chickens and successfully expressed H5 and MDP1 RNA transcripts. The sera of immunized chickens were collected prior to first immunization and every week after immunization; and analyzed using enzyme-linked immunosorbent assay (ELISA) and hemagglutination inhibition (HI) test.ResultsResults of competitive ELISA showed successful antibody responses two weeks post immunization. The HI test showed an increased in antibody titers during the course of experiment in group immunized with H5 and H5 + MDP1 vaccines. The result showed that the constructed DNA vaccines were able to produce detectable antibody titer in which the group immunized with H5 + MDP1 vaccine produced higher antibody comparing to H5 vaccine alone.ConclusionsThis study shows for the first time the usefulness of MDP1 as a genetic adjuvant for H5 DNA vaccine.

Co-administration of avian influenza virus H5 plasmid DNA with chicken IL-15 and IL-18 enhanced chickens immune responses

“…This is comparable to the studies conducted by our group where chickens immunized intramuscularly with the H5 DNA vaccine with genetic adjuvants, such as MDP-1, Esat-6 and HSP70 of the Mycobacterium tuberculosis, developed a higher HI titer compared to the H5 DNA vaccine alone [24-26]. However, all the previous studies required three vaccinations to achieve a comparable HI titer.…”

Selection of Adjuvants for Enhanced Vaccine Potency

“…Gram-positive enhancer matrix (GEM) particles derived from Lactococcus lactis was effective for intranasal vaccination with subunit flu vaccine in mice [398]. Other examples include a mixture from heat-killed Mycobacterium vaccae preparation [399] or a particular component, such as Neisseria meningitidis outer membrane [262] or mycobacterial binding protein 1 [400].…”

Antibody response to DNA vaccine against H5N1 avian influenza virus in broilers immunized according to three schedules.

“…A considerable number of publications report chicken immunization with DNA vaccines, especially with avian influenza antigens. Such studies sometimes included measurement of IgY humoral response in serum samples and analysis of its dynamics (Jalilian et al, 2010;Liniger et al, 2012), but most of them concentrated on hemag- glutinin inhibition tests and virus neutralization assays (Jiang et al, 2007;Shan et al, 2011;Lim et al, 2012). In this study, the specificity of the anti-HA antibodies induced by our experimental DNA vaccine was evaluated preliminarily using the IPMA test which enables detection of cells exposing HA on their surface, such as cells infected by the virus.…”