Safety of the novel vector vaccine against Brucella abortus based on recombinant influenza viruses expressing Brucella L7/L12 and OMP16 proteins, in cattle

Abstract

Citation: Tabynov K, Kydyrbayev Z, Ryskeldinova S, Yespembetov B, Syrymkyzy N, et al. (2015) eertechz AbstractThis paper presents the results of a study of the safety of new vector vaccine against B. abortus based on recombinant influenza A subtype H5N1 or H1N1 (viral constructs vaccine formulation) viruses expressing Brucella ribosomal protein L7/L12 and Omp16, in cattle. To increase the effectiveness of the vaccine, adjuvants such as Montanide Gel01 or chitosan were included in its composition. Immunization of cattle (5 animals per group) with the viral constructs vaccine formulation only, or its combination with adjuvants Montanide Gel01 or chitosan, were conducted via the conjunctival method using cross prime (influenza virus subtype H5N1) and booster (influenza virus subtype H1N1) vaccination schedules. Vaccine candidates were evaluated in comparison with the positive (B. abortus S19) and negative (PBS) controls. Comprehensive studies involving thermometry and clinical examination, hematology and biochemical blood analysis, showed that all of the viral constructs vaccine formulation, as well as their combination with adjuvants, compared to the commercial bacterial vaccine B. abortus S19 were completely safe in cattle. Furthermore it is shown that the developed vaccines can effectively differentiate vaccinated animals from infected animals. Brucella L7/L12 or Omp16 proteins. The influenza A virus contains a segmented genome consisting of eight negative-strand RNA fragments. Of these, the smallest fragment (NS) -encoding two proteins: viral nonstructural protein (NS1) and nuclear export protein (Nep) -is a convenient target for genetic manipulation as NS1 is able to tolerate foreign sequences exceeding its own length [25]. Thus, the ORF of NS1 was used for inserting Brucella sequences in this study. The А/Puerto Rico/8/34 (H1N1) strain was used as the backbone for obtaining influenza A virus vectors expressing Brucella L7/L12 or Omp16 sequences in the form of fusion proteins with the N-terminal 124 amino acid residues of NS1.Our previous studies have shown that a bivalent vaccine formulation comprising a mixture of recombinant influenza A virus subtype H5N1 or H1N1 expressing the ribosomal L7/L12 or Omp16 proteins in prime and booster immunization mode (via conjunctival injection) in cattle induced a strong antigen-specific T-cell immune response, and most importantly provided a high level of protectiveness comparable to the commercial B. abortus S19 vaccine and superior to the B. abortus S19 vaccine in combination with Montanide Gel01 adjuvant [24]. Based on this, the next stage of our study was to evaluate the safety of the proposed new live vector vaccine in cattle. Additionally, we evaluated the possibility of differentiating infected animals from vaccinated animals using the developed vaccine.

Safety of the novel influenza viral vector Brucella abortus vaccine in pregnant heifers

“…Our previous complex studies involving thermometry, clinical examination, hematology and blood biochemical analysis showed that the vector vaccine were completely safe for cattle compared to a commercial vaccine S19 (TABYNOV et al, 2014a). However, to completely confirm the safety of any kind of preventive preparation, especially brucellosis vaccines, is necessary to show that it does not induce abortion in vaccinated pregnant animals.…”

Improved influenza viral vector based Brucella abortus vaccine induces robust B and T-cell responses and protection against Brucella melitensis infection in pregnant sheep and goats

“…abortus ) we developed Flu-BA vaccine candidate in which a vector based on recombinant influenza virus subtypes H5N1 and H1N1 expresses the Brucella L7/L12 or Omp16 proteins from the NS1 (non-structural) gene open reading frame (ORF). In the past few years, we conducted many vaccine trials and demonstrated this vaccine’s safety and efficacy [6, 7]. Our results were comparable or even superior in vaccine trials comparing it to commercial vaccines made from B .…”

A new candidate vaccine for human brucellosis based on influenza viral vectors: development of immunization schedule in guinea pig model

“…With IVV subtype H5N1 (a pathogenic variety of in uenza virus), the attenuation was additionally achieved by removing the proteolytic cleavage site in the HA protein, that is, double attenuation was performed. During repeated re-inoculation in chick embryos, IVV retained all their basic biological properties, including signs of attenuation, and did not lose the brucellosis insertion segment [13], which indicates their genetic stability. In addition, the in uenza viral vectors we use are RNAcontaining viruses that are limited to cytoplasmic replication, thus eliminating the risk of integration and long-term persistence.…”

“…In this study, we used IVV type A of H5N1 subtype that express Brucella proteins Omp16, Omp19, L7/L12 or SOD from NS1 open reading frames at amino acid position 80. A detailed procedure for the construction of the IVV is described previously [13]. Obtained recombinant in uenza vectors (Flu-NS1-80-Omp16, Flu-NS1-80-L7/L12, Flu-NS1-80-Omp19, Flu-NS1-80-Cu-Zn SOD) were then used to produce vaccine samples.…”

“…Previously, we used recombinant In uenza A viruses of the H5N1 and H1N1 subtypes as vectors that express brucellosis immunodominant outer membrane proteins (Omp) 16 and ribosomal L7/L12 in order to develop a new Brucella abortus vaccine (Flu-BA) against brucellosis in cattle [12,13]. Now, the Flu-BA vaccine is registered in Kazakhstan (registration certi cate #RK-VP-1-3775-19 from January 14, 2019) and is at the stage of commercialization for vaccination of cattle against B. abortus infection.…”