• 생명과학회지
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• 제32권5호
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• pp.375-390
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• 2022

인수공통 호흡기바이러스인 인플루엔자바이러스 감염으로 인해 공중보건과 가축산업에 심각한 피해가 지속적으로 발생하고 있다. 인플루엔자 백신 접종을 통해 항원형이 일치하는 바이러스 감염에 대해 우수한 방어면역을 제공하고 있으나, 효과적인 바이러스 감염 제어에는 여전히 큰 공백이 존재하고 있다. 다양한 항원형을 갖는 바이러스에 동시방어가 가능한 범용인플루엔자백신 개발과 함께 바이러스 치료효과를 제공하는 항바이러스제의 개발도 중요한 접근법으로 고려되고 있다. 현재 널리 사용되고 있는 인플루엔자 항바이러스제의 불완전한 치료효과와 내성바이러스의 출현 등의 문제들로 인해 식물 유래 천연물의 항바이러스 활성에 대한 관심이 증가하고 있다. 특히, 현재 진행 중인 코로나-19 팬데믹은 범용적인 항바이러스 활성을 갖는 안전하고 효과적인 항바이러스제 개발의 필요성을 뚜렷이 보여준다. 본 리뷰는 현재까지 보고된 천연물의 항인플루엔자바이러스 활성을 요약하였다. 또한, 항바이러스 활성을 갖는 천연물의 바이러스 사멸활성과 면역증강활성을 이용하는 신규 백신개발과 면역증강제 개발 가능성에 대해서도 분석하였다.

• Journal of Microbiology and Biotechnology
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• 제16권2호
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• pp.318-324
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• 2006

In order to develop an oral vaccine to prevent H. pylori infection, we have expressed the hpaA gene of H. pylori K51 isolated from Korean patients, encoding 29-kDa HpaA that is known to be localized on the cell surface and flagella sheath, in a live delivery vector system, Lactococcus lactis. The hpaA gene, amplified by PCR using the genomic DNA of H. pylori K51, was cloned in the pGEX-2T vector, and the DNA sequence analysis revealed that the hpaA gene of H. pylori K51 had 99.7% and 94.8% identity with individual hpaA genes of the H. pylori 26695 strain (U.K) and the J99 strain (U.S.A). A polyclonal anti-HpaA antibody was raised in rats using GST-HpaA fusion protein as the antigen. The hpaA gene was inserted in an E. coli-L. lactis-shuttle vector (pMG36e) to express in L. lactis. Western blot analysis showed that the expression level of HpaA in the L. lactis transformant remained constant from the exponential phase to the stationary phase, without extracelluar secretion. These results indicate that the HpaA of H. pylori K51 was successfully expressed in L. lactis, and suggest that the recombinant L. lactis expressing HpaA may be applicable as an oral vaccine to induce a protective immune response against H. pylori.

• 한국동물위생학회지
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• 제34권2호
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• pp.95-102
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• 2011

Foot-and-mouth disease (FMD) is one of the most infectious diseases affecting cloven-hoofed animals including cattle, sheep, goats, and pigs. Seven serotypes of foot-and-mouth disease virus with multiple subtypes within each serotype have been identified until now. In particular, it has been demonstrated that the outbreak of the serotype Asia1 reported from China, Mongolia and North Korea since 2005 is mostly classified into genetic group V. Though it has been recommended that Asia1 Shamir strain can be used as a high priority vaccine by World References Laboratory for FMD, the complete nucleotide sequences of the strain has not yet been determined. In this study, to be prepared for Asia1 type viruses that may be brought into Korea, the complete genome sequence of this vaccine strain Asia1 Shamir including its 5' and 3' non-coding region was identified.

• Journal of Microbiology and Biotechnology
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• 제16권10호
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• pp.1529-1536
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• 2006

We cloned a gene of ompH(D:4) from pigs infected with P. multocida D:4 in Korea [16]. The gene is composed of 1,026 nucleotides coding 342 amino acids (aa) with a signal peptide of 20 aa (GenBank accession number AY603962). In this study, we analyzed the ability of the ompH(D:4) to induce protective immunity against a wild-type challenge in mice. To determine appropriate epitope(s) of the gene, one full and three different types of truncated genes of the ompH(D:4) were constructed by PCR using pET32a or pRSET B as vectors. They were named ompH(D:4)-F (1,026 bp [1-1026] encoding 342 aa), ompH(D:4)-t1 (693 bp [55-747] encoding 231 aa), ompH(D:4)-t2 (561 bp [187-747] encoding 187 aa), and ompH(D:4)-t3 (540 bp [487-1026] encoding 180 aa), respectively. The genes were successfully expressed in Escherichia coli BL21(DE3). Their gene products, polypeptides, OmpH(D:4)-F, -t1, -t2, and -t3, were purified individually using nickel-nitrilotriacetic acid (Ni-NTA) affinity column chromatography. Their $M_rs$ were determined to be 54.6, 29, 24, and 23.2 kDa, respectively, using SDS-PAGE. Antisera against the four kinds of polypeptides were generated in mice for protective immunity analyses. Some $50{\mu}g$ of the four kinds of polypeptides were individually provided intraperitoneally with mice (n=20) as immunogens. The titer of post-immunized antiserum revealed that it grew remarkably compared with pre-antiserum. The lethal dose of the wild-type pathogen was determined at $10{\mu}l$ of live P. multocida D:4 through direct intraperitoneal (IP) injection, into post-immune mice (n=5, three times). Some thirty days later, the lethal dose ($10{\mu}l$) of live pathogen was challenged into the immunized mouse groups [OmpH(D:4)-F, -t1, -t2, and -t3; n=20 each, two times] as well as positive and negative control groups. As compared within samples, the OmpH(D:4)-F-immunized groups showed lower immune ability than the OmpH(D:4)-t1, -t2, and -t3. The results show that the truncated-OmpH(D:4)-t1, -t2, and -t3 can be used for an effective vaccine candidate against swine atrophic rhinitis caused by pathogenic P. multocida (D:4) isolated in Korea.

• Journal of Plant Biotechnology
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• 제32권4호
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• pp.233-241
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• 2005

Plants have considerable advantages for the production of antigenic proteins because they provide an inexpensive source of protein and an easy administration of vaccine. Since a publication describing edible plant vaccine of HBsAg in 1992, a number of laboratories around the world have studied the use of plants as the bioreactor to produce antigenic proteins of human or animal pathogens. Over the last ten years, these works have been mainly focused on three major strategies for the production of antigenic proteins in plants: stable genetic transformation of either the nuclear or plastid genome, or transient expression in plants using viral vectors. As many antigenic proteins have been expressed in tobacco, also several laboratories have succeeded to express genes encoding antigenic proteins in other crop plants: potato, tomato, maize, carrot, soybean and spinach. At present many works for the production of edible plant vaccine against bacteria-mediated diseases have mostly performed the studies of enterotoxins and adhesion proteins. Also the development of new-type antigens (pili, flagella, surface protein, other enterotoxin and exotoxin etc.) is required for various targets and more efficacy to immunize against microorganism pathogens. Many works mostly studied in experimental animals had good results, and phase I clinical trial of LTB clearly indicated its immunogenic ability. On the other hand, edible plant vaccines have still problems remained to be solved. In addition to the accumulation of sufficient antigen in plants, human health, environment and agriculture regulation should be proven. Also oral tolerance, the physiological response to food antigens and commensal flora is the induction of a state of specific immunological unresponsiveness, needs to be addressed before plant-derived vaccine becomes a therapeutic option.

• Asian-Australasian Journal of Animal Sciences
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• 제2권2호
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• pp.103-114
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• 1989

Reciprocal crosses were conducted between three strains of Taiwan Country chickens, developed in the National Chung-Hsing University, and two strains of Single Comb White Leghorns, developed in the Taiwan Livestock Research Institute. Traits studied were growing performances, laying performances, egg quality traits and traits concerning disease resistance, including resistance to Marek's disease virus and immune responses to Newcastle disease virus vaccine and to sheep red blood cell. Results indicated that laying performances of Taiwan country chickens were much inferior to White Leghorns, but they matured earlier, their eggs had better shell strength and larger proportion of yolk, and their general disease resistance was much better than White Leghorns. Heterosis were found in laying performances and egg quality traits. The heterosis in laying traits was so large that the hybrid laid as many eggs and as large eggs as did pure strains of White Leghorns. Strategies on the improvement of native chickens and the utilization of genetic merits of native chickens were also discussed.

• 한국미생물·생명공학회지
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• 제33권2호
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• pp.142-147
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• 2005

The objective of this study was to develop a new potent antibacterial compound against bovine pneumoniae bacteria from medicinal plants or herbs. Among 65 kinds of medicinal plants and herbs, ethanol extracts of Citrus unishiu showed the highest solid yield of $54\%$. However, ethanal extracts from Agastache rugosa had the highest antibacterial activities against bovine pneumoniae bacteria, Mannheimia haemolytica A and Haemophilus somnus (size of clear zone: 16.0 mm and 10.0 mm, respectively). The antibacterial compound was also maximally extracted when the powder of A. rugosa was treated with $70\%$ ethanol at $45^{\circ}C$ for 12 hours.

• Journal of Veterinary Science
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• 제22권3호
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• pp.32.1-32.8
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• 2021

Feline calicivirus (FCV) is a highly infectious pathogen in cats and widely distributed worldwide with high genetic variation. Full-length open reading frame 2 of 5 from recently isolated Korean FCV isolates were sequenced and compared with those of global isolates. The results of phylogenetic analysis supported dividing global FCV isolates into two genogroups (type I and II) and demonstrated the presence of genogroup II in Korea, indicating their geographic spread in East Asia. High sequence variations in region E of the FCV isolates emphasizes that a novel vaccine needs to be developed to induce protective immunity against various FCV strains.

• Journal of Microbiology and Biotechnology
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• 제31권12호
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• pp.1601-1614
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• 2021

To overcome the ongoing COVID-19 pandemic, vaccination campaigns are the highest priority of majority of countries. Limited supply and worldwide disproportionate availability issues for the approved vaccines, together with concerns about rare side-effects have recently initiated the switch to heterologous vaccination, commonly known as mixing of vaccines. The COVID-19 vaccines are highly effective in the general population. However, none of the vaccines is 100% efficacious or effective, with variants posing more challenges, resulting in breakthrough cases. This review summarizes the current knowledge of immune responses to variants of concern (VOC) and breakthrough infections. Furthermore, we discuss the scope of heterologous vaccination and future strategies to tackle the COVID-19 pandemic, including fractionation of vaccine doses and alternative route of vaccination.

• 대한수의학회지
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• 제64권1호
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• pp.4.1-4.5
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• 2024

In this study, almost complete genomic sequences of porcine parvovirus (PPV)1 and PPV4 circulating in commercial pig farms in South Korea were obtained and analyzed. Important mutations that may be precursors to host changes, such as premature stop codons of PPV1 and frameshift mutations of PPV4, were observed in these sequences. A 27a-like strain of PPV1, known to show a lack of cross- neutralization against existing commercial vaccine strains, was identified by phylogenetic analysis. Given the active genetic evolution, the additional precursors to host changes and emerging new genotypes of PPVs need to be monitored through continuous sampling and genetic analysis.