• 한국임상수의학회지
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• 제28권1호
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• pp.113-121
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• 2011

Foot-and-mouth disease (FMD) is a severe vesicular disease of cloven-hoofed animals including domesticated ruminants and pigs. Acute clinical signs may be mild in sheep and goats but are associated with lameness in pigs and mouth lesions with vesicles in cattle. The required condition for a successful pathogen appears to be the ability to counteract both the host innate and adaptive immune response. FMD virus (FMDV) inhibits the induction of antiviral molecules and interferes with the secretory pathway in the infected cell. The surface expression of Major Histocompatibility Complex (MHC) class I molecules is reduced in infected cells. Thus, the ability of the host to recognize and eliminate virus infected cells is decreased. Furthermore, FMDV infection results in a rapid, but transient lymphopenia, reducing the number of T and B cells, and affecting T cell function. The virus appears to premature apoptosis-mediated cell death because it has a very short replication cycle and is able to rapidly produce large amounts of virus. FMDV engages the host protective response at multiple steps to ensure its effective replication and pathogenesis. This review describes the recent pathological and immunological studies to overcome the powerful abilities of FMDV to counteract defense mechanism of host.

• Clinical and Experimental Pediatrics
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• 제50권7호
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• pp.613-621
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• 2007

Hematopoietic stem cell transplantation (HSCT) has expanded and evolved substantially in the last decades to treat various malignant and nonmalignant diseases. However, the conditioning regimen can lead to transplantation related death by major organ dysfunction, severe infection and bleeding. In the allogeneic setting, graft versus host disease may also develop, making post-transplant management complex. To overcome these problems, new stem cell sources, stem cell mobilizing agents and new skills, nonmyeloablative stem cell transplantation including reduced intensity stem cell transplantation has been introduced in clinical practice, but problems remained so far. Recipients of stem cell transplant may be severely immunocompromised for many months after transplantation. Furthermore, long-term complications (endocrine, metabolic, relapse, second malignancies, etc) can develop. Pediatrician is open called on to participate in the evaluation and consideration of patients for possible transplant and long-term follow-up of HSCT patients. This review is intended as a basic overview of HSCT relevant to general pediatrician.

• BMB Reports
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• 제36권1호
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• pp.128-137
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• 2003

Matrix metalloproteinases (MMPs), zinc dependent proteolytic enzymes, cleave extracellular matrix (ECM: collagen, laminin, firbronectin, etc) as well as non-matrix substrates (growth factors, cell surface receptors, etc). The deregulation of MMPs is involved in many diseases, such as tumor metastasis, rheumatoid arthritis, and periodontal disease. Metastasis is the major cause of death among cancer patients. In this review, we will focus on the roles of MMPs in tumor metastasis. The process of metastasis involves a cascade of linked, sequential steps that involve multiple host-tumor interactions. Specifically, MMPs are involved in many steps of tumor metastasis. These include tumor invasion, migration, host immune escape, extravasation, angiogenesis, and tumor growth. Therefore, without MMPs, the tumor cell cannot perform successful metastasis. The activities of MMPs are tightly regulated at the gene transcription levels, zymogen activation by proteolysis, and inhibition of active forms by endogenous inhibitors, tissue inhibitor of metalloproteinase (TIMP), and RECK. The detailed regulations of MMPs are described in this review.

• IMMUNE NETWORK
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• 제11권6호
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• pp.428-430
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• 2011

We previously demonstrated that in vivo engagement of CD137, a member of TNF receptor superfamily, can delete allorective $CD4^+$ T cells through the induction of activation-induced cell death (AICD) in chronic graft-versus-host disease (cGVHD) and subsequently reverse established cGVHD. In this study, we further showed that agonistic anti-CD137 mAb was highly effective in triggering AICD of donor $CD8^+$ T cells as well as donor $CD4^+$ T cells in the $C57BL/6{\rightarrow}unirradiated$ $(C57BL/6\;{\times}\;DBA/2)F1$ acute GVHD model. Our results suggest that strong allostimulation should facilitate AICD of both alloreactive $CD4^+$ and $CD8^+$ T cells induced by CD137 stimulation. Therefore, depletion of pathogenic T cells using agonistic anti-CD137 mAb combined with potent TCR stimulation may be used to block autoimmune or inflammatory diseases mediated by T cells.

• Journal of Microbiology and Biotechnology
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• 제26권4호
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• pp.790-798
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• 2016

Chlamydiae, obligate intracellular bacteria, are associated with a variety of human diseases. The chlamydial life cycle undergoes a biphasic development: replicative reticulate bodies (RBs) phase and infectious elementary bodies (EBs) phase. At the end of the chlamydial intracellular life cycle, EBs have to be released to the surrounded cells. Therefore, the interactions between Chlamydiae and cell death pathways could greatly influence the outcomes of Chlamydia infection. However, the underlying molecular mechanisms remain elusive. Here, we investigated host cell death after Chlamydia infection in vitro, in L929 cells, and showed that Chlamydia infection induces cell necrosis, as detected by the propidium iodide (PI)-Annexin V double-staining flow-cytometric assay and Lactate dehydrogenase (LDH) release assay. The production of reactive oxygen species (ROS), an important factor in induction of necrosis, was increased after Chlamydia infection, and inhibition of ROS with specific pharmacological inhibitors, diphenylene iodonium (DPI) or butylated hydroxyanisole (BHA), led to significant suppression of necrosis. Interestingly, live-cell imaging revealed that Chlamydia infection induced lysosome membrane permeabilization (LMP). When an inhibitor upstream of LMP, CA-074-Me, was added to cells, the production of ROS was reduced with concomitant inhibition of necrosis. Taken together, our results indicate that Chlamydia infection elicits the production of ROS, which is dependent on LMP at least partially, followed by induction of host-cell necrosis. To our best knowledge, this is the first live-cell-imaging observation of LMP post Chlamydia infection and report on the link of LMP to ROS to necrosis during Chlamydia infection.

• 생명과학회지
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• 제30권4호
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• pp.402-409
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• 2020

신경괴사증바이러스(NNV)는 25 nm의 작은 입자 크기에 RNA1 (3.4 kb, RdRp), RNA2 (1.4 kb, capsid protein) 두 가닥의 RNA를 유전정보를 가진다. NNV는 1980년대 말 처음 보고된 이후 전 세계적으로 120여종의 어류에 감염을 일으키며 심각한 피해를 일으키고 있는 바이러스이다. NNV 감염에 의한 피해를 최소화하고 효율적인 백신들을 개발하기 위해서는 무엇보다 NNV 감염에 따른 세포내 신호전달체계를 이해할 필요가 있다. NNV는 세포내 감염 이후 숙주가 가진 바이러스 복제에 필요한 요소들을 이용할 수 있도록 숙주세포의 cell cycle arrest 등의 기작을 이용하는 것으로 알려졌다. 반면에 숙주 세포는 NNV와 감염된 세포를 제어하기 위해 RIG-1-like receptor signaling pathway 등을 통해 NNV 감염을 인지한 다음 IFN signaling pathway를 통해 항바이러스 작용에 필요한 ISG들을 발현시킨다. 또한 감염된 세포들을 사멸시키기 위해 ER stress를 통한 unfolded protein response (UPR), mitochondria-mediated cell death 작용을 통해 감염된 세포의 apoptosis를 유발한다. NNV 감염 기작에 대한 세포신호전달연구는 아직 초기단계이며 검증해야 할 pathway들이 아직도 많이 남아있는 상황이다. 따라서 NNV 감염과 연관된 다양한 세포신호전달체계를 탐색하고 질병 특이적인 세포신호전달체계를 이해함으로써 신속하고 정확한 진단법 및 백신 개발에 많은 도움이 될 것으로 생각된다.

• International Journal of Stem Cells
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• 제15권2호
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• pp.144-154
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• 2022

Background and Objectives: Neural stem cells (NSCs) remain in the mammalian brain throughout life and provide a novel therapeutic strategy for central nervous system (CNS) injury. Bone morphogenetic protein-6 (BMP-6) had shown a protective effect in different types of cells. However, the role of BMP-6 in NSCs is largely unclear. The present study was aimed to investigate whether BMP-6 could protect human NSCs (hNSCs) against the oxygen and glucose deprivation (OGD)-induced cell death. Methods and Results: Upon challenge with OGD treatment, cell viability was significantly decreased in a time-dependent manner, as indicated by the CCK-8 assay. BMP-6 could attenuate the OGD-induced cell injury in a dose-dependent manner and decrease the number of TUNEL-positive cells. Moreover, BMP-6 markedly weakened the OGD-induced alterations in the expression of procaspase-8/9/3 and reversed the expression of cleaved-caspase-3. Interestingly, noggin protein (the BMP-6 inhibitor) attenuated the neuroprotective effect of BMP-6 in cultured hNSCs. Furthermore, the p38 MAPK signaling pathway was activated by OGD treatment and BMP-6 markedly inhibited the phosphorylation of p38 in a concentration-dependent manner. Pretreatment with noggin abolished the effect of BMP-6 on p38 activation. SB239063, a selective p38 inhibitor, exerted similar effects with BMP-6 in protecting hNSCs against the OGD-induced apoptosis. These results indicated that blocking the phosphorylation of p38 might contribute to the neuroprotective effect of BMP-6 against the OGD-induced injury in hNSCs. Conclusions: These findings suggested that BMP-6 might be a therapeutic target in the OGD-induced cell death, which provides a novel therapeutic strategy for enhancing host and graft NSCs survival in hypoxic-ischemic brain injury.

• 한국식물병리학회:학술대회논문집
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• 한국식물병리학회 2003년도 정기총회 및 추계학술발표회
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• pp.13-13
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• 2003

When plants are infected by plant pathogens, rapid cell responses are initiated for further inhibition from fast invasion of pathogens. Hypersensitive response (HR) of plant is well known defense response stopping pathogenesis process through rapid cell death. However, informations on the signaling pathway from reception of pathogen by host plants to appropriate resistant responses are very limited to date. Efficient perception of infection by pathogens and well-programmed signalling mechanism for appropriate responses are important for survival of plants. Plant have developed a sophisticated network(s) of defense/stress responses, among which one of the earliest signalling pathways after perception (of stimuli) is the evolutionary conserved Rop GTPase and mitogen-activated protein kinase (MAPK) cascade.(중략)

• Journal of Microbiology and Biotechnology
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• 제20권1호
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• pp.224-228
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• 2010

The encapsulation of bacteria may be used to harness them for longer periods of time in order to make them viable, whereas antibiotic treatment would result in controlled release of therapeutic molecules. Encapsulated Escherichia coli GFP (green fluorescent protein) (E. coli GFP) was used here as a model for therapeutic substance - GFP fragments release (model of bioactive substances). Our aim was to evaluate the performance of bacteria encapsulated in hollow fibers (HFs) treated with antibiotic for induction of cell death. The polypropylene-surface-modified HFs were applied for E. coli encapsulation. The encapsulated bacteria were treated with tetracycline in vitro or in vivo during subcutaneous implantation into mice. The HF content was evaluated in a flow cytometer, to assess the bacteria cell membrane permeability changes induced by tetracycline treatment. It was observed that the applied membranes prevented release of bacteria through the HF wall. The E. coli GFP culture encapsulated in HF in vitro proved the tetracycline impact on bacteria viability and allows the recognition of the sequence of events within the process of bacteria death. Treatment of the SCID mice with tetracycline for 8 h proved the tetracycline impact on bacteria viability in vivo, raising the necrotic bacteria-releasing GFP fragments. It was concluded that the bacteria may be safely enclosed within the HF at the site of implantation, and when the animal is treated with antibiotic, bacteria may act as a local source of fragments of proteins expressed in the bacteria, a hypothetical bioactive factor for the host eukaryotic organism.

• Toxicological Research
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• 제17권
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• pp.217-218
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• 2001

In a series of our screening for immunomodulating substances, we isolated prodigiosin from the culture broth qf Serratia marcescens B-1231. This compound inhibited the T cell-mediated immune responses such as concanavalin A-induced proliferation, mixed lymphocyte response, local graft versus host reaction and T-dependent antibody response at nontoxic concentrations. However. prodigiosin did not effect B cell-mediated immune functions such as lipopolysaccharide-induced proliferation and -activated polyclonal antibody production at the same concentrations. Prodigiosin did not cause death in vitro to lymphocytes at effective concentrations (＜100 nM) and also did not show toxicity in vivo to lymphoid organs at effective dos-ages (10 and 30 mg/kg). The pharmacological potencies were comparable to the activities of well-known T-cell specific immunosuppressants such as cyclosporin A. In our continuing study, mechanism of action of PDG is investigated with respect to the effect of PDG on IL-2/IL-2R pathway and transcription factor.