• IMMUNE NETWORK
• /
• 제3권1호
• /
• pp.23-28
• /
• 2003

Background: Intracellular antibody specific to hepatitis B virus X protein (HBx) might be useful for studying the role of HBx in hepatocellular carcinogenesis and HBV replication. Methods: With variable region genes for H7 monoclonal anti-HBx Ab, we constructed a vector for bacterial expression of single chain Ab (scFv) and a vector for eukaryotic cell expression of it. The expression of H7 scFv and its binding activity against HBx was examined by immunoblotting and immunofluorescence microscopy. Results: H7 scFv expressed in bacterial cells retained reactivity to HBx. We demonstrated its intracytoplasmic expression in CosM6 eukaryotic cells. Conclusion: This is the first study showing the expression of intracellular anti-HBx Ab in eukaryotic cells. H7 scFv may be a good tool to study the function of HBx in HBV infection.

• Molecules and Cells
• /
• 제25권4호
• /
• pp.553-558
• /
• 2008

Essential aspects of the innate immune response to microbial infection appear to be conserved between insects and mammals. In order to identify new Drosophila melanogaster genes involved in the immune response, we performed gene expression profiling of Drosophila SL2 cells stimulated with bacterial (LPS/PGN) or fungal (curdlan) components using a cDNA microarray that contained 5,405 Drosophila cDNAs. We found that some genes were similarly regulated by LPS/PGN and curdlan. However, a large number, belonging to the functional classes of cell organization, development, signal transduction, morphogenesis, cell cycle, and DNA replication, displayed significant differences in their transcription profiles between the two treatments, demonstrating that bacterial and fungal components induce different immune response even in an in vitro cell system.

• 식물병연구
• /
• 제21권2호
• /
• pp.74-81
• /
• 2015

박과 작물에서 과일썩음병(bacterial fruit blotch)을 일으키는 Acidovorax citrulli를 종자로부터 검출하기 위한 특이적이고 민감한 nested-PCR 방법을 개발하였다. 본 연구에서는 Next Generation Sequencing을 이용하여 draft genome sequencing을 얻은 후 이를 분석하여 PCR 프라이머를 디자인하였고, 이들 프라이머의 A. citrulli에 대한 특이성을 확인하여 Ac-ORF 21F/Ac-ORF 21R의 nested PCR 프라이머를 최종 선발하였다. Ac-ORF 21F/Ac-ORF 21R는 오직 A. citrulli에서만 특이적으로 140bp 크기의 DNA를 증폭하였으며, 그 검출민감도는 1차 PCR 검출한계(10 ng genomic DNA/PCR)보다 검출한계를 10,000배 증가시켰다. 개발된 nested-PCR 방법을 통해 병원균을 인공접종한 수박 종자의 외부검사에서 $10^1cfu/ml$까지 인공 접종 한 모든 종자 시료에서 병원균을 검출하였고, 병원균을 인공접종 한 수박 종자의 내부검사에서는 병원균이 검출되지 않았다. 자연 감염 수박 종자의 외부검사에서는 10개의 반복 시료 중 2개에서, 그리고 종자 내부검사에서는 10개의 반복 시료 중 5개에서 A. citrulli를 검출하였다. 본 연구에서 개발한 nested-PCR은 특이성과 민감도가 높고 인공접종과 자연감염 수박 종자에서도 병원균의 검출이 가능하여 박과 작물의 종자로부터 A. citrulli를 검출하는데 효과적으로 사용될 수 있을 것으로 생각된다.

• 환경생물
• /
• 제40권4호
• /
• pp.433-441
• /
• 2022

Bacterial phytopathogen Pectobacterium causes soft rot disease in several vegetable crops globally, resulting in heavy agricultural losses at both the pre and postharvest stages. The present work was carried out to screen Kimchi cabbage genetic resources conserved at the National Agrobiodiversity Center, Rural Development Administration, Korea, for resistance against the soft rot pathogen Pectobacterium carotovorum subsp. carotovorum KACC 21701 over a period of three years (from 2020 to 2022). Infection of the phytopathogen was carried out at four-leaf stage and for each accession, twenty-five plants per germplasm were infected with KACC 21701. Kimchi cabbage cultivars Wangmatbaechu, Seoulbaechu, and CR Kiyoshi were used as control. Seven-days post-infection, the Disease Index (DI) values were manually recorded from zero to four, zero matched perfectly heathy plants and four completely dead plants. The 682 accessions of Kimchi cabbage exhibited varying degrees of disease resistance to KACC 21701 and thirty accessions, exhibiting a DI≤2, were considered for replication studies. During the replication studies, four landrace germplasms (IT102883, IT120036, IT120044, and IT120048) and one cultivar(IT187919) were confirmed to be moderately susceptible to KACC 21701. Results of the preliminary screening as well as replication studies were documented for the all the 682 germplasms. Addition of such information to the passport data of stored germplasms might serve as potential bio-resource for future breeders and researchers to develop resistant varieties or study the mechanisms involved in resistance of plants to such phytopathogen.

• Journal of Veterinary Science
• /
• 제22권2호
• /
• pp.18.1-18.12
• /
• 2021

Background: We previously elucidated the protective mechanism of Korean red ginseng oil (RGO) against Brucella abortus infection, and our phytochemical analysis revealed that palmitic acid (PA) was an abundant component of RGO. Consequently, we investigated the contribution of PA against B. abortus. Objectives: We aimed to investigate the efficacy of PA against B. abortus infection using a murine cell line and a murine model. Methods: Cell viability, bactericidal, internalization, and intracellular replication, western blot, nitric oxide (NO), and superoxide (O₂^-) analyses and flow cytometry were performed to determine the effects of PA on the progression of B. abortus infection in macrophages. Flow cytometry for cytokine analysis of serum samples and bacterial counts from the spleens were performed to determine the effect of PA in a mouse model. Results: PA did not affect the growth of B. abortus. PA treatment in macrophages did not change B. abortus uptake but it did attenuate the intracellular survivability of B. abortus. Incubation of cells with PA resulted in a modest increase in sirtuin 1 (SIRT1) expression. Compared to control cells, reduced nitrite accumulation, augmented O₂^-, and enhanced pro-inflammatory cytokine production were observed in PA-treated B. abortus-infected cells. Mice orally treated with PA displayed a decreased serum interleukin-10 level and enhanced bacterial resistance. Conclusions: Our results suggest that PA participates in the control of B. abortus within murine macrophages, and the in vivo study results confirm its efficacy against the infection. However, further investigations are encouraged to completely characterize the mechanisms involved in the inhibition of B. abortus infection by fatty acids.

• 한국미생물·생명공학회지
• /
• 제34권4호
• /
• pp.289-298
• /
• 2006

3',5'-cyclic adenosine monophosphate (cAMP) is an important molecule, which mediates diverse cellular processes. For example, it is involved in regulation of sugar uptake/catabolism, DNA replication, cell division, and motility in various acterial species. In addition, cAMP is one of the critical regulators for syntheses of virulence factors in many pathogenic bacteria. It is believed that cAMP acts as a signal for environmental changes as well as a regulatory factor for gene expressions. Therefore, intracellular concentration of cAMP is finely modulated by according to its rates of synthesis (by adenylate cyclase), excretion, and degradation (by cAMP phosphodiesterase). In the present review, we discuss the bacterial physiological characteristics governed by CAMP and the molecular mechanisms for gene regulation by cAMP. Furthermore, the effect of cAMP on phosphotransferase system is addressed.

• Genomics & Informatics
• /
• 제8권4호
• /
• pp.170-176
• /
• 2010

The Ribonucleotide reductases (RNR) are essential enzymes that catalyze the conversion of nucleotides to deoxynucleotides in DNA replication and repair in all living organisms. The RNRs operate by a free radical mechanism but differ in the composition of subunit, cofactor required and regulation by allostery. Based on these differences the RNRs are classified into three classesclass I, class II and class III which depend on oxygen, adenosylcobalamin and S-adenosylmethionine with an iron sulfur cluster respectively for radical generation. In this article thirty seven sequences belonging to each of the three classes of RNR were analyzed by using various tools of bioinformatics. Phylogenetic analysis, dot-plot comparisons and motif analysis was done to identify a number of differences in the three classes of RNRs. In this research article, we have attempted to decipher evolutionary relationship between the three classes of RNR by using bioinformatics approach.

• Childhood Kidney Diseases
• /
• 제12권1호
• /
• pp.1-10
• /
• 2008

Nucleic scids transfer the genetic information for serving a central biological purpose. The nucleic acids are polymers of nucleotides and they are mainly ribonucleic acid(RNA) and deoxyribonucleic acid(DNA). The nucleotides are stoichiometrically composed of five-carbon sugars, nitrogeneous bases, and phosphoric acids. The chemistry of nucleic acids and characteristics of different genomes are decribed for further study. Most of DNA genomes tend to be circular including bacterial genomes and eukaryotic mitochondrial DNA. Eukaryotic chromosomes in cells, in contrast, are generally linear. The ends of linear chromosomes are called telomeres. The genomes of different species, such as mammals, plants, invertebrates can be compared with the chromosome ends. The telomeric complex allows cells to distinguish the random DNA breaks and natural chromosomal ends. The very ends of chromosomes cannot be replicated by any ordinary mechanisms. The shortening of telomeric DNA templates in semiconservative replication is occurred with each cell division. The short telomere length is critically related to aging, tumors and dieases.

• Journal of Microbiology and Biotechnology
• /
• 제31권7호
• /
• pp.912-920
• /
• 2021

SOS response is a conserved response to DNA damage in prokaryotes and is negatively regulated by LexA protein, which recognizes specifically an "SOS-box" motif present in the promoter region of SOS genes. Myxococcus xanthus DK1622 possesses a lexA gene, and while the deletion of lexA had no significant effect on either bacterial morphology, UV-C resistance, or sporulation, it did delay growth. UV-C radiation resulted in 651 upregulated genes in M. xanthus, including the typical SOS genes lexA, recA, uvrA, recN and so on, mostly enriched in the pathways of DNA replication and repair, secondary metabolism, and signal transduction. The UV-irradiated lexA mutant also showed the induced expression of SOS genes and these SOS genes enriched into a similar pathway profile to that of wild-type strain. Without irradiation treatment, the absence of LexA enhanced the expression of 122 genes that were not enriched in any pathway. Further analysis of the promoter sequence revealed that in the 122 genes, only the promoters of recA2, lexA and an operon composed of three genes (pafB, pafC and cyaA) had SOS box sequence to which the LexA protein is bound directly. These results update our current understanding of SOS response in M. xanthus and show that UV induces more genes involved in secondary metabolism and signal transduction in addition to DNA replication and repair; and while the canonical LexA-dependent regulation on SOS response has shrunk, only 5 SOS genes are directly repressed by LexA.

• 대한소아치과학회지
• /
• 제27권4호
• /
• pp.549-557
• /
• 2000

치아우식증은 치아구조의 국소적, 침윤적, 분자적인 붕괴로 특징지워지는 치아 경조직에 대한 세균성질환이다. 이런 치아 우식증의 주 원인균인 S. mutans의 치태형성과 증식에 대해 아동의 구강에서 분리된 L. lactis 51의 작용을 연구하여 다음과 같은 결과를 얻었다. 1. 비커 와이어 검사에서 S. mutans와 L. lactis 51의 혼합배양시 S. mutans 단독배양에 비해 치태의 무게가 감소하였다. 2. S. mutans는 S. mutans와 L. lactis 51의 혼합 배양에 비교하여 S. mutans 단독배양시에 생균수가 감소하였다. 3. S. mutans와 L. lactis 51은 M17Y broth에서 단독 및 혼합배양시 배양 12시간 때까지 증가하다가 24시간 때에 감소 하였으나, M17YS broth에서는 S. mutans와 L. lactis 51의 혼합배양시 S. mutans의 생균수가 시간이 지남에 따라 감소하였다. 4. L. lactis 51의 배양 상청액은 S. mutans의 치태형성과 증식에 대해 억제 작용을 하지 못하였다. 5. M17YS broth에서의 L. lactis 51 배양 상청액 성분의 thin layer chromatography에서 자당과 과당이 계속 검출되었다. 이상의 결과를 종합하면 구강에서 분리된 L. lactis 51는 S. mutans의 인공치태 형성과 증식을 억제시키는 것으로 사료된다.