• Korean Journal of Veterinary Research
• /
• v.46 no.3
• /
• pp.225-234
• /
• 2006

In the present study toxicity and immunostimulating activity of the lectin(KML-C), which was extracted from Korean mistletoe(Viscum album coloratum) were investigated in swine. To determine the toxicity, lectin was injected into thigh or cervical muscles of 4-week-old piglets(Landrace) and observed clinically and pathologically. For determination of the immnunostimulating activity, lectin($0.7{\mu}g/kg$ of body weight)-adjuvanted vaccine of Aujeszky's disease virus(ADV)(NYJ1-87) which was inactivated by 0.2% formalin was injected into the cervical muscle of antibody-negative piglets in the same age group. Subpopulation of the immune cells and serum neutralizing(SN) antibodies in the piglets were examined after vaccination, and resistance of the piglets against challenge by virulent NYJ1-87 was further examined. The results were also compared with those from piglets injected with aluminum hydroxide [$Al(OH)_3$]-adjuvanted vaccine of inactivated NYJ1-87 and NYJ1-87 vaccine without adjuvant, and the results are as follows. By injection of lectin with $30{\mu}g/kg$ of body weight to the thigh muscle, all of 12 piglets died after signs such as dyspnea, fever, systemic erythema and subcutaneous hemorrhages, and lesions pertaining to poisonous hepatitis and dysfunction of kidney were observed. By injection of lectin with $7{\mu}g/kg$ of body weight to the thigh muscle, all of 12 piglets showed signs such as edema and cutaneous hemorrhage in the injected area, lameness and depression, and lesions pertaining to poisonous hepatitis and dysfunction of kidney were observed. By injection of lectin with 1, 3 and $5{\mu}g/kg$ of body weight to the thigh muscle of each one piglet, signs such as congestion, induration and grayish coloration in the injected area, depression and inappetence were observed in all piglets. Toxic changes were also observed in the liver and kidney of piglets by lectin of 3 and $5{\mu}g$. By injection of lectin with 0.5 and $0.7{\mu}g/kg$ of body weight to the cervical muscle of each 9 piglets, all piglets were clinically normal and there were no significant changes in blood counts and chemistry values. Whereas, epithelial swelling and vacuolation of convoluted tubules were observed from one piglet injected with lectin of $0.7{\mu}g$, and necrosis and fibrosis of muscular fiber were observed in the muscle of one piglet injected with lectin of $0.5{\mu}g$. Only population of sIgM+ B lymphocytes increased among immune cells in all of 15 piglets immunized with lectin($0.7{\mu}g/kg$ of body weight)-adjuvanted vaccine, while compared to those in $Al(OH)_3$-adjuvanted vaccine and vaccine without adjuvant. No additional stimulation to the immune cells was recognized when lectin was added to $Al(OH)_3$-adjuvanted vaccine. In piglets immunized with lectin-adjuvanted vaccine, SN titers in reciprocal values for loge were 1.3-4.0 at 1-4 weeks after vaccination, which was similar to those with 1.0-3.3 by vaccine without adjuvant but lower than those with 2.0-5.7 by $Al(OH)_3$-adjuvanted vaccine. Also, no additional increase in the SN titers was recognized when lectin was added to $Al(OH)_3$-adjuvanted vaccine. Piglets immunized with lectin-adjuvanted vaccine were resistant to challenge by the virulent NYJ1-87 at 4 weeks after vaccination, and the SN titers reached to 5.0 one week after challenge, which was higher than those with 4.0 by vaccine without adjuvant but somewhat lower than those with 7.7 by $Al(OH)_3$-adjuvanted vaccine.

• IMMUNE NETWORK
• /
• v.3 no.2
• /
• pp.110-117
• /
• 2003

Background: The usefulness of DNA vaccine at priming step of heterologous prime-boost vaccination led to DNA vaccine closer to practical reality. DNA vaccine priming followed by recombinant viral vector boosting via systemic route induces optimal systemic immunity but no mucosal immunity. Mucosal vaccination of the reversed protocol (recombinant viral vector priming-DNA vaccine boosting), however, can induce both maximal mucosal and systemic immunity. Here, we tried to address the reason why the mucosal protocol of prime-boost vaccination differs from that of systemic vaccination. Methods: To address the importance of primary immunity induced at priming step, mice were primed with different doses of DNA vaccine or coadministration of DNA vaccine plus mucosal adjuvant, and immunity including serum IgG and mucosal IgA was then determined following boosting with recombinant viral vector. Next, to assess influence of humoral pre-existing immunity on boosting $CD8^+$ T cell-mediated immunity, $CD8^+$ T cell-mediated immunity in B cell-deficient (${\mu}K/O$) mice immunized with prime-boost regimens was evaluated by CTL assay and $IFN-{\gamma}$-producing cells. Results: Immunity primed with recombinant viral vector was effectively boosted with DNA vaccine even 60 days later. In particular, animals primed by increasing doses of DNA vaccine or incorporating an adjuvant at priming step and boosted by recombinant viral vector elicited comparable responses to recombinant viral vector primed-DNA vaccine boosted group. Humoral pre-existing immunity was also unlikely to interfere the boosting effect of $CD8^+$ T cell-mediated immunity by recombinant viral vector. Conclusion: This report provides the important point that optimally primed responses should be considered in mucosal immunization of heterologous prime-boost regimens for inducing the effective boosting at both mucosal and systemic sites.

• Journal of fish pathology
• /
• v.5 no.1
• /
• pp.19-27
• /
• 1992

A formalized bacterin(FKC) of Edwardsiella tarda, conjugated with/without Freund's complete adjuvant(FCA), Freund's incomplete adjuvant(FIA) and potassium aluminium sulfate(PAS), was administered by intraperitoneal injection to tilapia respectively. The tilapia were reared under indoor recirculating filter system. There were agglutinin titer increment in the tilapia which were administered not only FKC bacterin but also adjuvanted vaccines. But the producing time of the highest level of antibody in the immunized tilapia was different among vaccine preparation, i. e. FKC+FCA group and PAS+FKC group are between the 2nd and the 4th week, and FKC alone group is the 2nd week. In the challenge experiment with $2.5{\times}10^7\;CFU/ml$ or $2.5{\times}10^8\;CFU/ml$ of E. tarda T1123 to the tilapia immunized with vaccines, RPS above sixty was recorded both challenge dose in the tilapia which were 3 weeks after immunization with FKC+FCA, PAS+FKC and FKC alone, and the former dose 8 weeks after immunization with FCA+FKC and PAS+FKC. There were some resistance enhancement against E. tarda in the tilapia which were injected with adjuvant alone than that of control. As the results, the FCA or PAS adjuvanted vaccine is effective to sustain the defensible period against edwardsiellosis.

• IMMUNE NETWORK
• /
• v.23 no.2
• /
• pp.16.1-16.19
• /
• 2023

Bacillus Calmette-Guerin (BCG) vaccine is the only licensed vaccine for tuberculosis (TB) prevention. Previously, our group demonstrated the vaccine potential of Rv0351 and Rv3628 against Mycobacterium tuberculosis (Mtb) infection by directing Th1-biased CD4⁺ T cells co-expressing IFN-γ, TNF-α, and IL-2 in the lungs. Here, we assessed immunogenicity and vaccine potential of the combined Ags (Rv0351/Rv3628) formulated in different adjuvants as subunit booster in BCG-primed mice against hypervirulent clinical Mtb strain K (Mtb K). Compared to BCG-only or subunit-only vaccine, BCG prime and subunit boost regimen exhibited significantly enhanced Th1 response. Next, we evaluated the immunogenicity to the combined Ags when formulated with four different types of monophosphoryl lipid A (MPL)-based adjuvants: 1) dimethyldioctadecylammonium bromide (DDA), MPL, and trehalose dicorynomycolate (TDM) in liposome form (DMT), 2) MPL and Poly I:C in liposome form (MP), 3) MPL, Poly I:C, and QS21 in liposome form (MPQ), and 4) MPL and Poly I:C in squalene emulsion form (MPS). MPQ and MPS displayed greater adjuvancity in Th1 induction than DMT or MP did. Especially, BCG prime and subunit-MPS boost regimen significantly reduced the bacterial loads and pulmonary inflammation against Mtb K infection when compared to BCG-only vaccine at a chronic stage of TB disease. Collectively, our findings highlighted the importance of adjuvant components and formulation to induce the enhanced protection with an optimal Th1 response.

• Journal of Microbiology and Biotechnology
• /
• v.14 no.3
• /
• pp.490-497
• /
• 2004

Although the E. coli heat-labile enterotoxin B subunit (LTB) is known to be a potent mucosal adjuvant towards co-administrated unrelated antigens and immunoregulator in T-helper 1-type-mediated autoimmune diseases, a more efficient and useful LTB is still required for prospective vaccine adjuvants. To determine whether a novel chimeric LTB subunit would produce an enhanced mucosal adjuvant activity and immune response, a number of LTB subunits were genetically fused with chimeric proteins using the epitope genes of the envelope glycoprotein E2 (gp51-54) from the classical swine fever virus (CSFV). It was found that the total serum immunoglobulin (Ig) levels of BALB/c mice orally immunized with chimeric proteins containing an N-terminal linked LTB subunit (LE1, LE2, and LE3) were higher than those of mice immunized with LTB, E2 epitope, and chimeric proteins that contained a C-terminal linked LTB subunit. In particular, immunization with LE1 markedly increased both the total serum Ig and fecal IgA level compared to immunization with LTB or the E2 epitope. Accordingly, the current results demonstrated that the LTB subunit in a chimeric protein exhibited a strong mucosal adjuvant effect as a carrier molecule, while the chimeric protein containing the LTB subunit stimulated the mucosal immune system by mediating the induction of antigen-specific serum Ig and mucosal IgA. Consequently, an LE1-mediated mucosal response may contribute to the development of effective antidiarrhea vaccine adjuvants.

• Journal of fish pathology
• /
• v.22 no.1
• /
• pp.45-52
• /
• 2009

Zebrafish was firstly applied to an experimental model for scuticociliatosis caused by Philasterides dicentrarchi, a facultative parasitic ciliate in cultured marine fish. The susceptibility of zebrafish to infection of P. dicentrarchi was assessed by intraperitoneal injection of the ciliates, which produced typical symptoms of scuticociliatosis and significant mortality. The potential use of zebrafish as a model to evaluate the vaccine efficacy against scuticociliatosis was analyzed by immunization of zebrafish with the ciliates lysate. Furthermore, the effect of different adjuvants, such as Quillaja saponin (QS), Montanide, and Freund’s incomplete adjuvant (FIA) on the protective efficacy of the vaccine was investigated. Groups of zebrafish injected with QS or Montanide alone showed higher survival of fish against challenge test compared to control fish. The results suggest that adjuvant-mediated enhancement of innate immune responses play important roles in protection of fish against scuticociliatosis. The considerably high survival in the fish immunized with the antigen alone indicates that the ciliate lysate itself is highly immunogenic to zebrafish, which can elicit protective immune responses. The protective potential of the antigen, ciliate lysate, was enforced through combined administration with adjuvants including QS, Montinide and FIA. No or low mortalities in the groups of fish immunized with the antigen plus adjuvants suggests that the adaptive immune responses of zebrafish might be accelerated by the adjuvants or the protective potential of the antigen and adjuvants might synergistically interact. In spite of several shortcomings such as difficulties in sampling of serum and leucocytes enough to routine immunological analyses, zebrafsih might be the most convenient experimental animal for scuticociliatosis.

• IMMUNE NETWORK
• /
• v.22 no.5
• /
• pp.41.1-41.16
• /
• 2022

The human antimicrobial peptide LL-37 has chemotactic and modulatory activities in various immune cells, including dendritic cells. Because of its characteristics, LL-37 can be considered an adjuvant for vaccine development. In this study, we confirmed the possible adjuvant activity of LL-37 in mucosal vaccine development against Middle East respiratory syndrome-coronavirus (MERS-CoV) by means of intranasal immunization in C57BL/6 and human dipeptidyl peptidase 4 (hDPP4)-transgenic (hDPP4-Tg) mice. Intranasal immunization using the receptor-binding domain (RBD) of MERS-CoV spike protein (S-RBD) recombined with LL-37 (S-RBD-LL-37) induced an efficient mucosal IgA and systemic IgG response with virus-neutralizing activity, compared with S-RBD. Ag-specific CTL stimulation was also efficiently induced in the lungs of mice that had been intranasally immunized with S-RBD-LL-37, compared with S-RBD. Importantly, intranasal immunization of hDPP4-Tg mice with S-RBD-LL-37 led to reduced immune cell infiltration into the lungs after infection with MERS-CoV. Finally, intranasal immunization of hDPP4-Tg mice with S-RBD-LL-37 led to enhanced protective efficacy, with increased survival and reduced body weight loss after challenge infection with MERS-CoV. Collectively, these results suggest that S-RBD-LL-37 is an effective intranasal vaccine candidate molecule against MERS-CoV infection.

• KSBB Journal
• /
• v.25 no.6
• /
• pp.497-506
• /
• 2010

Vaccine is a protective clinical measure capable of persuading immune system against infectious agents. Vaccine can be categorized as live attenuated and inactivated. Live attenuated vaccines activate immunity similar to natural infection by replicating living organisms whereas inactivated vaccines are either whole cell vaccines, eliciting immune response by killed organisms,or subunit vaccines, stimulating immunity by non-replicating sub cellular parts. The components of vaccine play a critical role in deciding the immune response mediated by the vaccine. The innate immune responds against the antigen component. Adjuvants represent an importantcomponent of vaccine for enhancing the immunogenicity of the antigens. Subunit vaccines with isolated fractions of killed and recombinant antigens are mostly co-administered with adjuvants. The delivery system of the vaccine is another essential component to ensurethat vaccine is delivered to the right target with right dosage form. Furthermore, vaccine delivery system ensures that the desired immune response is achieved by manipulating the optimal interaction of vaccine and adjuvantwith the immune cell. The aforementioned components along with routes of administration of vaccine are the key elements of a successful vaccination procedure. Vaccines can be administered either orally or by parenteral routes. Many groups had made remarkable efforts for the development of new vaccine and delivery system. The emergence of new vaccine delivery system may lead to pursue the immunization goals with better clinical practices.

• Korean Journal of Microbiology
• /
• v.45 no.2
• /
• pp.91-98
• /
• 2009

Infectious bursal disease (IBD) caused by the infectious bursal disease virus (IBDV) has an important economic impact on the poultry industry worldwide. This study examined the adjuvant effects of a plasmid encoding chicken interleukin-6 (pcDNA-ChIL-6) and levamisole (LMS) on in ovo prime-boost vaccination using a genetic vaccine (pcDNA-VP243) to prime in chicken followed by a killed-vaccine boost. A pcDNA-VP243 was injected into the amniotic sac alone or in combination with a pcDNA-ChIL-6 or LMS at embryonation day 18, followed by an intramuscular injection of killed IBD vaccine at 1 week of age. The chicken were orally challenged with very virulent IBDV (vvIBDV) strain at 3 weeks of age and observed for 10 days. No mortality was observed in the groups that received the pcDNA-VP243 alone and pcDNA-VP243 plus pcDNA-ChIL-6 or LMS compared to 100% mortality in unvaccinated challenge control group. However, as determined by bursal damage (the presence of IBDV RNA, B/B ratio, and lesion score), a pcDNA-VP243 alone group was superior to pcDNA-VP243 plus pcDNA-ChIL-6 or LMS groups in the protection against post-challenge. These findings suggest that in ovo priming with genetic vaccine and boosting with killed vaccine is an effective strategy for protecting chicken against vvIBDV and the addition of pcDNA-ChIL-6 or LMS did not enhance protective immunity.

• Clinical and Experimental Vaccine Research
• /
• v.13 no.2
• /
• pp.146-154
• /
• 2024

Purpose: Infection by the intracellular apicomplexan parasite Toxoplasma gondii has serious clinical consequences in humans and veterinarians around the world. Although about a third of the world's population is infected with T. gondii, there is still no effective vaccine against this disease. The aim of this study was to develop and evaluate a multimeric vaccine against T. gondii using the proteins calcium-dependent protein kinase (CDPK)1, CDPK2, CDPK3, and CDPK5. Materials and Methods: Top-ranked major histocompatibility complex (MHC)-I and MHC-II binding as well as shared, immunodominant linear B-cell epitopes were predicted and linked using appropriate linkers. Moreover, the 50S ribosomal protein L7/L12 (adjuvant) was mixed with the construct's N-terminal to increase the immunogenicity. Then, the vaccine's physicochemical characteristics, antigenicity, allergenicity, secondary and tertiary structure were predicted. Results: The finally-engineered chimeric vaccine had a length of 680 amino acids with a molecular weight of 74.66 kDa. Analyses of immunogenicity, allergenicity, and multiple physiochemical parameters indicated that the constructed vaccine candidate was soluble, non-allergenic, and immunogenic, making it compatible with humans and hence, a potentially viable and safe vaccine candidate against T. gondii parasite. Conclusion: In silico, the vaccine construct was able to trigger primary immune responses. However, further laboratory studies are needed to confirm its effectiveness and safety.