• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.11a
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• pp.61-67
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• 1994

One fundamental problem in developing an AIDS vaccine is antigenic variation of HIV. Despite a substantial induced immune response in gp120-immunized monkeys and humans, high titers of V3-directed type specific neutralizing antibodies may not be sufficient to neutralize continuously emerging new isolates. Several studies analyzing anti-gp120 antibodies in HIV-infected individuals have clearly indicated that most broadly neutralizing antibodies are directed to conformation-dependent epitopes. Therefore, it seems important to evaluate the potential efficacy of candidate gp120 vaccines at inducing such antibodies, that might be potentially protective against multiple HIV strains. One concern in the development of any recombinant protein as a vaccine is its stability when mixed with an adjuvant. This could be a particularly important factor for recombinant gp120, given the conformational nature of its major, broadly neutralizing, epitopes. We hypothesized that gp120 complexed with recombinant CD4 could stabilize the conformation-dependent epitopes and effectively deliver these epitopes to the immune system. In this study, a soluble gp120-CD4 complex in Syntex Adjuvant Formulation was tested in mice to analyze the anti-gp120 antibody response. With the aim of defining the fine specificity and neutalizing activities of the immune response, 17Mabs were generated and characterized. The studies indicate that the gp120-CD4 complex elicits neutralizing anti-gp120 antibodies, most of which are directed to the conformation dependent epitopes.

• Journal of Microbiology and Biotechnology
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• v.15 no.6
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• pp.1384-1387
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• 2005

Hantavax(R) is one of the killed Hantavirus vaccines, and is commercially available in South Korea. This vaccine was developed by inactivation of virus isolated from infected suckling mouse brain with formalin. Although Hantavax(R) can induce neutralizing antibodies in vaccinees, the strength of this induction and the duration of the humoral immune response are controversial issues. In this study, we studied the native conformation of the killed vaccine by antigen-capture reverse transcriptase polymerase chain reaction with patient and vaccinee sera containing neutralizing antibodies against Hantavirus. The results showed that Hantavax(R) could bind HTNV patient and vaccinee sera like live virus, suggesting that the integrity of the viral epitope is maintained in Hantavax(R) and induces the protective antibodies, even though the virus was inactivated with formalin.

• Journal of Microbiology
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• v.39 no.1
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• pp.49-55
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• 2001

We have developed four chicken hybridomas secreting monoclonal antibodies to induce a protective immune response against the chicken disease avian coccidiosis, caused by the intestinal parasite Eimeria acervulina. Huwever, since the amount of antibodies secreted from these hybridomas is too low or sometimes they lost their ability to produce antibodies, the hybridoma method is not satisfactory in the production of large amounts of chicken monoclonal antibodies. To bypass these problems, we applied the antibody engineering technology using polymerase chain reaction. We cloned and determined the sequences of variable domains of the four chicken monoclonal antibodies, namely, 2-1, 5D11, 13C8 and 8C3. The sequences comparison to germline sequences skewed that the gene con version mechanism might contribute to developing diversification of heavy and λ-light chains in chicken antibodies. Several pseudogene families regarded as donors in gene conversion were identified at each framework region and the complementarily determining region of λ-light chains. In addition, as expected, numerous changes of nucleotide sequences such as nucleotide substitution, insertion and deletion were found predominantly in complementarity determining regions, which are likely to be somatic hypermutations as a result of affinity maturation in antibody-producing cells.

• Proceedings of the Korean Society of Life Science Conference
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• 2005.09a
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• pp.83-83
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• 2005

• Korean Journal of Veterinary Service
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• v.33 no.3
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• pp.213-221
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• 2010

The results from a total of 412 blood samples consisted of 187 samples from regular visiting group (RV), 94 samples from first visiting group (FV), 52 samples from abandoned group (A), 54 samples from special breeder group (SB), and 25 samples from preliminary breeder group (PB) showed that RV(94.7%) and SB(88.9%) groups had the higher levels of protective antibody, but PB (36.0%) group revealed the lowest level. Among 96 blood samples with lower protective antibody levels, 14 samples (14.6%), 72 samples (75.0%) and 10 samples (10.4%) were below the protective antibody levels to distemper/parvo-virus, distemper only and parvovirus only, respectively. These results implied that antibody to parvovirus was well generated than that to distemper. Eighty six samples (20.9%) showed the protective antibody titer under 1:96 to distemper and 24 samples (5.8%), the protective antibody titer under 1:40 to parvovirus.

• YAKHAK HOEJI
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• v.52 no.6
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• pp.494-499
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• 2008

The role of antibody in the fungal infections is controversial. However, our previous reports showed a certain epitope in Candida albicans cell wall (CACW) induces protective antibody. A major problem is that the epitope isolation requires tremendous time with high cost. This aspect led us to investigate a simple way inducing protective antibodies against C. albicans. In the present study, we determined if $18{\beta}$-glycyrrhetinic acid ($18{\beta}$-GA) from Glabrae Radix (a family of Leguminosae) has immunoadjuvant activity. Data displayed that the $18{\beta}$-GA suppressed proliferations of both T- and Blymphocytes at high concentrations, whereas below 20 ${\mu}M$ concentration the compound supported the proliferations. These observations indicate that $18{\beta}$-GA has immunoregulatory activity. Based on this observation, an immunoadjuvant effect was examined at the low concentration. Results from animal experiments showed that CACW combined with or without $18{\beta}$-GA produced the anti-C. albicans antiserum in mice. Nevertheless, the CACW combined with $18{\beta}$-GA formula only protected mice against disseminated candidiasis (P<0.05). These data implicate that $18{\beta}$-GA has immunoadjuvant activity, which may provoke the CACW antigen to induce protective antibody. Currently, we are investigating possible mechanism of how the $18{\beta}$-GA provokes such protective immunity against the disseminated disease.

• Korean Journal of Veterinary Service
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• v.21 no.3
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• pp.277-284
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• 1998

Serum samples were collected from 100 breeders and their progeny 600 broilers. The breeders and broilers were vaccinated against infectious bronchitis(IB), infectious bursal disease(IBD) and Newcastle disease(ND) viruses according to general vaccination program. The antibodies in serum samples against IB, IBD and ND viruses were detected by ELISA using commercial ELISA kit. Geometric mean titer(GMT) of ELISA was monitored from 1-day-old to 35-day-old broilers and compared to that of breeder chickens. The GMT of ELISA to IB, IBD and ND was declined half level of the day old broiler's antibody titers at about 4, 9 and 4 days of age. The GMT of ELISA to IB, IBD and ND was declined than that of protective antibody titer at about 12, 11, and 15 days of age. Thereafter, the GMT of ELISA to IB, ND were declined and disappeared according to age of broilers. The GMT of ELISA to IBD was declined according to age of broilers, but at 25 days of age increased and 31 days of age increased than that of protective antibody titer. Taken together, these studies led to conclusion that time-course of antibody titers of broilers from vaccinated breeders and that of progeny broliers which vaccinated according to vaccine program. Those are very important data to design vaccine program to breeders and broilers.

• Parasites, Hosts and Diseases
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• v.39 no.3
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• pp.233-240
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• 2001

Although some reports have been published on the protective effect of antibodies to Toxoplasma gondii surface membrane proteins, few address the inhibitory activity of antibodies to dense granular proteins (GRA proteins) . Therefore, we performed a series of experiments to evaluate the inhibitory effects of monoclonal antibodies (mAbs) to GRA proteins (GRA2, 28 kDa; GRA6, 32 kDa) and surface membrane protein (SAGI, 30 kDa) on the invasion of T. gondii tachyzoites. Passive immunization of mice with one of three mAbs following challenge with a lethal dose of tachyzoites significantly increased survival compared with results for mice treated with control ascites. The survival times of mice challenged with tachyzoties pretreated with anti-GRA6 or anti-SAG 1 mAb were significantly increased. Mice that received tachyzoties pretreated with both mAb and complement had longer survival times than those that received tachyzoites pretreated with mAb alone. Invasion of tachyzoites into fibroblasts and macrophages was significantly inhibited in the anti-GRA2, anti-GRA6 or anti-SAG 1 mAb pretreated group. Pretreatment with mAb and complement inhibited invasion of tachyzoites in both fibroblasts and macrophages. These results suggest that specific antibodies to dense-granule molecules may be useful for controlling infection with T. gondii.

• Clinical and Experimental Vaccine Research
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• v.12 no.2
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• pp.97-106
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• 2023

Purpose: Rabies is a fatal but preventable disease with proper pre-exposure anti-rabies vaccination (ARV). Dogs, as household pets and strays, are the reservoir and vector of the disease, and dog bites have been associated with human rabies cases in Sri Lanka over the past few years. However, other susceptible species having frequent contact with humans may be a source of infection. One such species is sheep and immunity following ARV has never been tested in sheep reared in Sri Lanka. Materials and Methods: We have tested serum samples from sheep reared in the Animal Centre, Medical Research Institute of Sri Lanka for the presence of anti-rabies antibodies following ARV. Sheep serum samples were tested with Bio-Pro Rabies enzyme-linked immunosorbent assay (ELISA) antibody kits used for the first time in Sri Lanka and our results were verified by a seroneutralization method on cells (fluorescent antibody virus neutralization, FAVN test) currently recommended by World Organization for Animal Health and World Health Organization. Results: Sheep received annual ARV and maintained high neutralizing antibody titers in their serum. No maternal antibodies were detected in lamb around 6 months of age. Agreement between the ELISA and FAVN test, i.e., coefficient concordance was 83.87%. Conclusion: Annual vaccination in sheep has an effect on maintaining adequate protection against rabies by measurements of anti-rabies antibody response. Lambs need to be vaccinated earlier than 6 months of age to achieve protective levels of neutralizing antibodies in their serum. Introducing this ELISA in Sri Lanka will be a good opportunity to determine the level of anti-rabies antibodies in animal serum samples.

• Pediatric Infection and Vaccine
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• v.20 no.2
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• pp.53-62
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• 2013

Purpose: The cross-protection of 7-valent pneumococcal conjugate vaccine (PCV7) against vaccine-related serotypes has been controversial. We investigated the serological properties of cross-protective antibodies against vaccine-related serotypes 6A, 6C, and 19A induced in young children aged 12-23 months after booster immunization of PCV7. Methods: IgG and IgM antibody concentrations and opsonic index (OI) against vaccine serotypes 6B and 19F and vaccine-related serotypes 6A, 6C, and 19A were measured by ELISA and opsonophagocytic killing assay (OPA) in 4 selected immunesera. The serological properties and antigenic specificity of protective antibodies were determined by IgM depletion of immunesera, OPA, and competitive OPA against serogroup 6 and 19 pneumococci. Results: Compared to pre-IgM depleted immunesera, OI of IgM-depleted immunesera against 6B and 19F decreased and OI against 6A, 6C, and 19A decreased, too. In competition OPA, free 6B and 19F polysaccharide completely inhibited the immune protection against vaccine-related serotypes 6A, 6C, and 19A as well as vaccine types 6B and 19F. Conclusions: The booster immunization of PCV7 certainly induced cross-protective antibodies against vaccine-related serotypes 6A, 6C, and 19A with both IgG and IgM isotypes. Furthermore, IgM antibodies are more highly contributed to opsonophagocytic activity against vaccine-related serotypes as well as most of vaccine types than do IgG antibodies. Further studies are needed for the more immunized sera in the children as well as adults.