• Parasites, Hosts and Diseases
• /
• 제62권1호
• /
• pp.75-84
• /
• 2024

Ancylostoma ceylanicum is a zoonotic soil-derived nematode that parasitizes the intestines of humans and animals (dogs and cats), leading to malnutrition and iron-deficiency anemia. Helminth parasites secrete calreticulin (CRT), which regulates or blocks the host's immune response. However, no data on A. ceylanicum calreticulin (Ace-CRT) are available. We investigated the biological function of recombinant Ace-CRT (rAce-CRT). rAce-CRT showed reliable antigenicity and stimulated the proliferation of mouse splenocytes and canine peripheral blood mononuclear cells. Quantitative reverse-transcription PCR assays revealed that rAce-CRT primarily promoted the expression of T helper 2 cytokines, particularly IL-13, in canine peripheral blood lymphocytes. rAce-CRT inhibited complement-mediated sheep erythrocyte hemolysis in vitro. Our findings indicate that Ace-CRT plays an immunomodulatory role and may be a promising candidate molecule for a hookworm vaccine.

• 대한화학회지
• /
• 제54권3호
• /
• pp.291-294
• /
• 2010

본 연구에서는 다양한 농도의 BCzVBi를 청색 형광도판트, DPVBi를 청색 호스트 물질로 적용한 청색OLED 소자를 제작하였다. 최적화된 고효율 청색 OLED 소자의 적층 구조는 NPB (500 ${\AA}$)/DPVBi:BCzVBi-6%(150 ${\AA}$)/$Alq_3$(300 ${\AA}$)/Liq(20 ${\AA}$)/Al (1000 ${\AA}$)으로 구성되었다. 청색 OLED의 최대휘도는 구동전압 13.8V에서13200 cd/$m^2$이고 전류밀도 및 최대효율은 각각 1000 cd/$m^2$의 휘도에서 26.4 mA/$cm^2$, 구동전압 3.9 V에서 4.24 cd/A 이었다. 도핑된 청색 OLED 소자의 발광효율은 도핑되지 않은 소자의 2배에 이른 반면 색좌표는 (0.16, 0.19)로 서로 비슷하였다. BCzVBi가 6% 도핑된 청색 OLED 445 nm와 470 nm에 2개의 EL 스펙트럼의 Peak이 존재하는 반면 도핑되지 않은 순수한 DPVBi 청색OLED 소자는 456 nm에서의 유일한 Peak만을 보여주고 있다. 이는 호스트 물질인 DPVBi의 LUMO와 도판트 물질인 BCzVBI의 LUMO 사이에 분자 진동에 의한 페르스터 에너지 전이에 기인한 것이다.

• Parasites, Hosts and Diseases
• /
• 제29권2호
• /
• pp.121-128
• /
• 1991

Toxoplasma gondii를 HL-60 세포와 함께 in vitro 배양시 Toxopsasma 침투 정도가 각 세포에서 균일하지 않으므로 세포의 주기에 따른 일정 phase가 그 침투에 좋은 환경을 제공할 것이라는 추론으로 HL-60세포 주기를 동시화(synchronization)하여 각 stage에서 변화를 관찰하였다. 동시화는 과량의 thymidine이 DNA 합성을 억제함을 이용하여 2mM thymidine을 10시간 간격으로 각 24, 18시간 동안 처리하여 (double thymidine block method) S (synthetic) phase를 진행하는 세포를 얻었고 이후 30시 간 동안 13회의 간격을 두고 $5{\times}10^6/ml$의 Toxoplasma를 첨가하여 1시간 동안 배양하였다. 숙주세포의 동시화 정도는 (1) 3H-thymidine의 표지량 (2) mitotic index 측전 및 (3) 세포수의 증가를 통해 확인하였다. Toxoplasma의 침투 정도는 S phase중에서도 배지에서 thymidine을 제거한 후 3시간 경과시가 그 전후에 비해 6배 이상 높았으며 특히 이 시기는 DNA 합성이 최고가 되는 점과 일치하였다. 침투된 Toxoplasma 수의 변화 외에 세포의 모양도 상당한 변화가 있었고 이는 19시간 후 2번째 S phase에서도 약하나마 관찰되었다 실험 결과를 통해 특정 약 1시간 동안 일어나는 어떤 세포의 변화가 Toxoplasma 침투에 중요한 역할을 한다는 것을 알 수 있었다. 이는 원충 기생충의 숙주세포 흡착과 interiorization과정에 receptor가 관련되고 몇 receptor는 세포주기에 따라 발현이 조절되는 사실로부터 $G_1/S$ 경계부터 3시간째에 발현되면서 Togopzasma를 유인하는 receptor molecule의 존재 가능성을 시사하였다.

• Archives of Pharmacal Research
• /
• 제25권6호
• /
• pp.895-902
• /
• 2002

Monocytes and macrophages playa major role in defense mechanism of the host response to tumor, in part through the secretion of several potent products and macrophage cytokines. Monocytes and tissue macro phages produce at least two groups of protein mediators of inflammation, interleukin 1 (IL-1) and tumor necrosis factor (TNF). Recent studies emphasizes that TNF and IL-1 modulate the inflammatory function of endothelial cells, leukocytes, and fibroblasts. In this study, our work is directed toward studying the in vitro effects of Korean propolis on the ability to induce cellular and secretory responses in murine macrophage cell line, RAW 264.7. It was found that Water Extract of Korean Propolis (WEP) could activate macro phages by producing cytokines. The production of the macrophage cytokines, IL-1 and TNF-$\alpha$, by RAW 264.7 treated with WEP was examined from 2.5 $\mu\textrm{g}$/ml up to 25 $\mu\textrm{g}$/ml with dose dependent manner. Nitric oxide (NO) production was also increased when cells were exposed to combination of LPS and WEP from 2.5 $\mu\textrm{g}$/ml up to 25 $\mu\textrm{g}$/ml. At high dose of WEP (50 to 100 $\mu\textrm{g}$/ml) used to prescribe for anti-inflammatory and analgesic medicine showed inhibition of NO production in LPS-stimulated macrophage. Besides cytokine production, NO release, surface molecule expression and cell morphologic antigen expression were increased in response to the stimulation by WEP. These results suggested WEP may function through macrophage activation.

• 미생물학회지
• /
• 제50권2호
• /
• pp.87-94
• /
• 2014

인체의 항상성 유지에 필수적인 물질로 알려진 산화질소는 인체를 침입한 미생물로부터 보호하는 면역반응에서 매우 중요한 역할을 담당하고 있다. 산화질소는 미생물에 직간접적으로 작용하여 다양한 기전으로 항균작용을 나타낸다. 항생제의 심각한 내성이 심각한 사회적 문제로 대두되면서 새로운 계열의 항생제 개발이 절실한 시점에서 항균물질로서의 산화질소에 대한 연구가 활발히 진행되고 있다. 하지만 매우 짧은 반감기와 기체분자인 산화질소를 항생제로 이용하기 위해서는 산화질소의 저장과 방출을 제어할 전략 필요하다. 본 총설에서는 산화질소의 체내에서의 생화학적 특성과 항균작용을 나타내는 다양한 기전에 대해 설명하였다. 또한 산화질소 방출을 조절하여 항균작용을 향상시키는 최근의 연구에 대해 알아보았다.

• Parasites, Hosts and Diseases
• /
• 제55권4호
• /
• pp.375-384
• /
• 2017

Trichomonas vaginalis is a pathogen that triggers severe immune responses in hosts. T. vaginalis ${\alpha}$-actinin 2, $Tv{\alpha}$-actinin 2, has been used to diagnose trichomoniasis. This study was undertaken to examine the role of $Tv{\alpha}$-actinin 2 as an antigenic molecule to induce immune responses from humans. Western blot analysis using anti-$Tv{\alpha}$-actinin 2 antibodies indicated its presence in the secreted proteins of T. vaginalis. ELISA was employed to measure cytokine production by vaginal epithelial cells, prostate cells, mouse dendritic cells (DCs), or T cells stimulated with T. vaginalis or $Tv{\alpha}$-actinin 2 protein. Both T. vaginalis and $rTv{\alpha}$-actinin 2 induced cytokine production from epithelial cell lines, including IL-10. Moreover, $CD4^+CD25^-$ regulatory T cells (Treg cells) incubated with $rTv{\alpha}$-actinin 2-treated DCs produced high levels of IL-10. These data indicate that $Tv{\alpha}$-actinin 2 modulates immune responses via IL-10 production by Treg cells.

• Environmental Analysis Health and Toxicology
• /
• 제15권3호
• /
• pp.69-80
• /
• 2000

ADP-rubosylation may be involved in the process of macrophage activation. Nitric oxide (NO) has emerged as an important intracellular and interacellular regulatory molecule with function as diverse as vasodilation, neural communication or host defense. NO is derived from the oxidation of the terminal guanidino nitrogen atom of L-arginine by the NADPH -dependent enzyme, nitric oxide synthase (NOS) which is one of the three different isomers in mammalian tissues. Since NO can exert protective or regulatory functions in the cell at a low concentration while toxic effects at higher concentrations, its role may be tightly regulated in the cell. Therefore, this paper was focused on signal transduction pathway of NO synthesis, role of endogenous TGF-$\beta$ in NO production. effect of NO on superoxide formation. Costimulation of murine peritoneal macrophages with interferon-gamma (IFN-γ) and phorbol 12-myristate 13-acetate (PMA) increased both NO secretion and mRNA expression of inducible nitric oxide synthase (iNOS) when PMA abolished costimulation. Pretreatmnet of the cells with PMA abolished costimuation effects due to the depletion of protein kinase C (PKC) activities . The involvement of PKC in NO secretion could be further confirmed by PKC inhibitor, stauroprine, and phorbol ester derivative, phorbol 12,13-didecanoate. Addition of actinomycine D in IFN-γ plus PMA stimulated cells inhibited both NO secretion and mRNA expression of iNOS indication that PMA stabilizes mRNA of iNOS . Exogenous TGF-$\beta$ reduced NO secretion in IFN -γ stimulated murine macrophages. However addition of antisense oligodeoxynucleotide (ODN) to TGF-$\beta$ to this system recovered the ability of NO production and inhibited mRNA expression of TGF-$\beta$. ACAS interactive laser cytometry analysis showed that transportation of FITC -labeled antisense ODN complementary to TGF-$\beta$ mRNA could be observed within 5 min and reached maximal intensity in 30 min in the murine macrophage cells. NO released by activated macrophages inhibits superoxide formation in the same cells . This inhibition nay be related on NO-induced auto -adenosine diphosphate (ADP) -ribosylation . In addition, ADP-ribosylation may be involved in the process of macrophage activation .

• Journal of Microbiology and Biotechnology
• /
• 제26권3호
• /
• pp.596-602
• /
• 2016

Staphylococcus aureus, like other gram-positive pathogens, has evolved a large repertoire of virulence factors as a powerful weapon to subvert the host immune system, among which alpha-hemolysin (Hla), a secreted pore-forming cytotoxin, plays a preeminent role. We observed a concentration-dependent reduction in Hla production by S. aureus in the presence of sub-inhibitory concentrations of isorhamnetin, a flavonoid from the fruits of Hippophae rhamnoides L., which has little antibacterial activity. We further evaluate the effect of isorhamnetin on the transcription of the Hla-encoding gene hla and RNAIII, an effector molecule in the agr system. Isorhamnetin significantly down-regulated RNAIII expression and subsequently inhibited hla transcription. In a co-culture of S. aureus and lung cells, topical isorhamnetin treatment protected against S. aureus-induced cell injury. Isorhamnetin may represent a leading compound for the development of anti-virulence drugs against S. aureus infections.

• International Journal of Industrial Entomology and Biomaterials
• /
• 제4권2호
• /
• pp.155-162
• /
• 2002

Cytochrome P45O (CYP) gene has been known to play one of the most important roles in metabolizing the exogenous materials. In insect, CYP is particularly known to detoxify toxic materials by adding oxygen molecule to the hydrophobic region of the materials. Thus, CYP-dependent metabolism is associated with the adaptation of insect to host plant chemicals. This in turn is known to be one of the driving forces for CYP diversification. In the present study, we cloned seven gene fragments of CYP 4 (CYP4) family from the midgut of the beet armyworm, Spodoptera exigua, through RT.PCT, Sequence analysis of the product showed the gene fragment to contain an open reading frame of ~150 amino acids, consisted of ~450 bp. The cloned gene fragments contained typical, conserved regions found in CYP4 family. Pairwise comparison of the deduced amino acid sequences among seven clones ranged in divergence from 0% to 52.86% and resulted in five distinct clones. The other two clones were identical or differ by one amino acid respectively to the corresponding clone, although each differed by ten nucleotides. Analysis of correlation between GenBank-registered, full length CYP4 and the cloned fragments resulted in statistically significant relationship ($r^{2}$ = 0.96085; p < 0.001), suggesting utility of the partial sequences as such full-length sequences. Phylogenetic analysis of the clones with GenBank-registered insect and mammal CYP4 family sequences by parsimony and several distance methods subdivided the clones into two groups: tones belonging to CYP4S and the others to CYP4M families.

• Restorative Dentistry and Endodontics
• /
• 제27권5호
• /
• pp.543-551
• /
• 2002

Nitric oxide (NO) is a small molecule (mol. wt. 30 Da) and oxidative free radical. It is uncharged and can therefore diffuse freely within and between cells across membrane. Such characteristics make it a biologically important messenger in physiologic processes such as neurotransmission and the control of vascular tone. NO is also highly toxic and is known to acts as a mediator of cytotoxicity during host defense. NO is synthesized by nitric oxide synthase (NOS) through L-arginine/nitric oxide pathway which is a dioxygenation process. NO synthesis involves several participants, three co-substrates, five electrons, five co-factors and two prosthetic groups. Under normal condition, low levels of NO are synthesized by type I and III NOS for a short period of time and mediates many physiologic processes. Under condition of oxidant stress, high levels of NO are synthesized by type II NOS and inhibits a variety of metabolic processes and can also cause direct damage to DNA. Such interaction result in cytostasis, energy depletion and ultimately cell death. NO has the potential to interact with a variety of intercellular targets producing diverse array of metabolic effects. It is known that NO is involved in hemodynamic regulation, neurogenic inflammation, re-innervation, management of dentin hypersensitivity on teeth. Under basal condition of pulpal blood flow, NO provides constant vasodilator tone acting against sympathetic vasoconstriction. Substance P, a well known vasodilator, was reported to be mediated partly by NO, while calcitonin-gene related peptide has provided no evidence of its relation with NO. This review describes the roles of NO in dental pulp in addition to the known general roles of it.