• Parasites, Hosts and Diseases
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• v.60 no.6
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• pp.379-391
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• 2022

Leishmaniasis is a serious parasitic disease caused by Leishmania spp. transmitted through sandfly bites. This disease is a major public health concern worldwide. It can occur in 3 different clinical forms: cutaneous, mucocutaneous, and visceral leishmaniasis (CL, MCL, and VL, respectively), caused by different Leishmania spp. Currently, licensed vaccines are unavailable for the treatment of human leishmaniasis. The treatment and prevention of this disease rely mainly on chemotherapeutics, which are highly toxic and have an increasing resistance problem. The development of a safe, effective, and affordable vaccine for all forms of vector-borne disease is urgently needed to block transmission of the parasite between the host and vector. Immunological mechanisms in the pathogenesis of leishmaniasis are complex. IL-12-driven Th1-type immune response plays a crucial role in host protection. The essential purpose of vaccination is to establish a protective immune response. To date, numerous vaccine studies have been conducted using live/attenuated/killed parasites, fractionated parasites, subunits, recombinant or DNA technology, delivery systems, and chimeric peptides. Most of these studies were limited to animals. In addition, standardization has not been achieved in these studies due to the differences in the virulence dynamics of the Leishmania spp. and the feasibility of the adjuvants. More studies are needed to develop a safe and effective vaccine, which is the most promising approach against Leishmania infection.

• Archives of Plastic Surgery
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• v.50 no.2
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• pp.188-193
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• 2023

Vascular injury following traumatic knee injury quoted in the literature ranges from 3.3 to 65%, depending on the magnitude and pattern of the injury. Timely recognition is crucial to ensure the revascularization is done within 6 to 8 hours from the time of injury to avoid significant morbidity, amputation, and medicolegal ramifications. We present a case of an ischemic limb following delayed diagnosis of popliteal artery injury after knee dislocation. Even though we have successfully repaired the popliteal artery, the evolving ischemia over the distal limb poses a reconstruction challenge. Multiple surgical debridement procedures were performed to control the local tissue infection. Free tissue transfer with chimeric latissimus dorsi flap was done to resurface the defect. However, the forefoot became gangrenous despite a free muscle flap transfer. His limb appeared destined for amputation in the vicinity of tissue and recipient vessels, but we chose to use a cross-leg free flap as an option for limb salvage.

• Journal of Korean Neurosurgical Society
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• v.66 no.4
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• pp.356-381
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• 2023

Although immunotherapy has been broadly successful in the treatment of hematologic malignancies and a subset of solid tumors, its clinical outcomes for glioblastoma are still inadequate. The results could be due to neuroanatomical structures such as the blood-brain-barrier, antigenic heterogeneity, and the highly immunosuppressive microenvironment of glioblastomas. The antitumor efficacy of endogenously activated effector cells induced by peptide or dendritic cell vaccines in particular has been insufficient to control tumors. Effector cells, such as T cells and natural killer (NK) cells can be expanded rapidly ex vivo and transferred to patients. The identification of neoantigens derived from tumor-specific mutations is expanding the list of tumor-specific antigens for glioblastoma. Moreover, recent advances in gene-editing technologies enable the effector cells to not only have multiple biological functionalities, such as cytokine production, multiple antigen recognition, and increased cell trafficking, but also relieve the immunosuppressive nature of the glioblastoma microenvironment by blocking immune inhibitory molecules, which together improve their cytotoxicity, persistence, and safety. Allogeneic chimeric antigen receptor (CAR) T cells edited to reduce graft-versus-host disease and allorejection, or induced pluripotent stem cell-derived NK cells expressing CARs that use NK-specific signaling domain can be a good candidate for off-the-shelf products of glioblastoma immunotherapy. We here discuss current progress and future directions for T cell and NK cell therapy in glioblastoma.

• Clinical and Experimental Vaccine Research
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• v.13 no.2
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• pp.146-154
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• 2024

Purpose: Infection by the intracellular apicomplexan parasite Toxoplasma gondii has serious clinical consequences in humans and veterinarians around the world. Although about a third of the world's population is infected with T. gondii, there is still no effective vaccine against this disease. The aim of this study was to develop and evaluate a multimeric vaccine against T. gondii using the proteins calcium-dependent protein kinase (CDPK)1, CDPK2, CDPK3, and CDPK5. Materials and Methods: Top-ranked major histocompatibility complex (MHC)-I and MHC-II binding as well as shared, immunodominant linear B-cell epitopes were predicted and linked using appropriate linkers. Moreover, the 50S ribosomal protein L7/L12 (adjuvant) was mixed with the construct's N-terminal to increase the immunogenicity. Then, the vaccine's physicochemical characteristics, antigenicity, allergenicity, secondary and tertiary structure were predicted. Results: The finally-engineered chimeric vaccine had a length of 680 amino acids with a molecular weight of 74.66 kDa. Analyses of immunogenicity, allergenicity, and multiple physiochemical parameters indicated that the constructed vaccine candidate was soluble, non-allergenic, and immunogenic, making it compatible with humans and hence, a potentially viable and safe vaccine candidate against T. gondii parasite. Conclusion: In silico, the vaccine construct was able to trigger primary immune responses. However, further laboratory studies are needed to confirm its effectiveness and safety.

• Clinical and Experimental Pediatrics
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• v.57 no.10
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• pp.434-439
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• 2014

Treatment outcomes of pediatric cancers have improved greatly with the development of improved treatment protocols, new drugs, and better supportive measures, resulting in overall survival rates greater than 70%. Survival rates are highest in acute lymphoblastic leukemia, reaching more than 90%, owing to risk-based treatment through multicenter clinical trials and protocols developed to prevent central nervous system relapse and testicular relapse in boys. New drugs including clofarabine and nelarabine are currently being evaluated in clinical trials, and other targeted agents are continuously being developed. Chimeric antigen receptor-modified T cells are now attracting interest for the treatment of recurrent or refractory disease. Stem cell transplantation is still the most effective treatment for pediatric acute myeloid leukemia (AML). However, in order to reduce treatment-related death after stem cell transplantation, there is need for improved treatments. New drugs and targeted agents are also needed for improved outcome of AML. Surgery and radiation therapy have been the mainstay for brain tumor treatment. However, chemotherapy is becoming more important for patients who are not eligible for radiotherapy owing to age. Stem cell transplant as a means of high dose chemotherapy and stem cell rescue is a new treatment modality and is often repeated for improved survival. Drugs such as temozolomide are new chemotherapeutic options. In order to achieve 100% cure in children with pediatric cancer, every possible treatment modality and effort should be considered.

• Molecules and Cells
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• v.24 no.3
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• pp.378-387
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• 2007

The Bcl-2 family of proteins interacts at the mitochondria to regulate apoptosis. However, the anti-apoptotic Bcl-2 and $Bcl-X_L$ are not completely localized to the mitochondria. In an attempt to generate Bcl-2 and $Bcl-X_L$ chimeras that are constitutively localized to the mitochondria, we substituted their C-terminal transmembrane tail or both the C-terminal transmembrane tail and the adjacent loop with the equivalent regions from Bak or Bax mutant (BaxS184V) as these regions determine the mitochondrial localization of Bak and Bax. The effects of these substitutions on subcellular localization and their activities were assessed following expression in HeLa and CHO K1 cells. The substitution of the C-terminal tail or the C-terminal tail and the adjacent loop of Bcl-2 with the equivalent regions from Bak or the Bax mutant resulted in its association with the mitochondria. This change in subcellular localization of Bcl-2 chimeras triggered cells to undergo apoptotic-like cell death. The localization of this Bcl-2 chimera to the mitochondria may be associated with the disruption of mitochondrial membrane potential. Unlike Bcl-2, the loop structure adjacent to the C-terminal tail in $Bcl-X_L$ is crucial for its localization. To localize the $Bcl-X_L$ chimeras to the mitochondria, the loop structure next to the C-terminal tail in $Bcl-X_L$ protein must remain intact and cannot be substituted by the loop from Bax or Bak. The chimeric $Bcl-X_L$ with both its C-terminal tail and the loop structure replaced by the equivalent regions of Bak or Bax mutant localized throughout the entire cytosol. The $Bcl-X_L$ chimeras that are targeted to the mitochondria and the wild type $Bcl-X_L$ provided same protection against cell death under several death inducing conditions.

• IMMUNE NETWORK
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• v.4 no.1
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• pp.31-37
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• 2004

Background: 1-8D gene is a member of human 1-8 interferon inducible gene family and is shown to be overexpressed in fresh colon cancer tissues. Three peptides 1-6, 3-5 and 3-7 derived from 1-8D gene were shown to have immunogenicity against colon cancer. Methods: To study tumor immunotherapy of these peptides we established an adoptive transfer model. $D^{b-/-}{\times}{\beta}2$ microglobulin (${\beta}2m$) null mice transgenic for a chimeric HLA-A2.1/$D^b-{\beta}2m$ single chain (HHD mice) were immunized with irradiated peptide-loaded RMA-S/HHD/B7.1 transfectants. Spleens were removed after last immunization, and splenocytes were re-stimulated in vitro. Lymphocytes from vaccinated HHD mice were transferred together with IL-2 to the tumor bearing nude mice that were challenged S.C. with the HCT/HHD/B7 colon carcinoma cell line that was found to grow in these mice. Results: Peptide 3-5 was found to be highly effective in CTL activity. Adoptively transferred anti-peptide 3-5 cytolytic T lymphocytes caused significant retardation in tumor growth. Conclusion: This study shows that peptide 3-5 can be the most effective candidate for the vaccine of adoptive immunotherapy against colon cancer.

• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1735-1740
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• 2008

Clone PERV-C (A3) env was isolated from the genomic DNA of domestic pig (Sus scrofa domesticus) in Korea to investigate the molecular properties of PERV-C. The nucleic acid homologies between the PERV-MSL (type C) reference and the PERV-C(A3) clone was 99% for env, but a single base pair deletion was found in the transmembrane (TM) region of the env open reading frame. To examine the functional characteristics of truncated PERV-C env, we constructed a replication-incompetent retroviral vector by replacing the env gene of the pCL-Eco retrovirus vector with PERV-C env. A retroviral vector bearing PERV-C/A chimeric envelopes was also created to complement the TM defect. Our results indicated that truncated PERV-C env was not infectious in human cells as expected. Interestingly, however, the vector with the PERV-C/A envelope was able to infect 293 cells. This observation suggests that recombination within PERV-C TM could render PERV-C infectious in humans. To further characterize PERV-C/A envelopes, we constructed an infectious molecular clone by using a PCR-based technique. This infectious molecular clone will be useful to examine more specific regions that are critical for human cell tropism.

• The Plant Pathology Journal
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• v.20 no.3
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• pp.212-219
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• 2004

Three isolates of Cucumber mosaic virus (CMV) from lily plants showing mosaic and distortion symptoms were detected by reverse-transcriptase polymerase chain reaction (RT-PCR) using primers specific to Cucumovirus genus namely, LK-CMV, LK4-CMV, and LKS-CMV. Restriction enzymes patterns of the RT-PCR products revealed that the lily isolates belonged to subgroup IA of CMV. In terms of biological properties, the lily isolates have highly similar but distinct pathogenicity as reported in other lily strains and ordinary strains of CMV. To characterize the molecular properties, cDNAs containing coat protein (CP) gene and 3' non-coding region (NCR) of RNA3 for the isolates were cloned and their nucleotide sequences were determined. The CP similarity (218 amino acids) was highly homologous (>97％) with that of subgroup I CMV strains. However, an additional 20-nulcleotide long segment was only present in 3' NCR of lily isolates, which form an additional stem-loop RNA structure. By using chimeric construct exchange cDNA containing 3'NCR of LK-CMV into the full-length cDNA clone of RNA3 of Fny-CMV, this additional segment may prove to be significant in the identification and fitness of the virus in lily plants. The pathology of zucchini squash infected by F1F2L3-CMV, a pseudorecombinant virus was showed to change drastically the severe mosaic and stunting symptom into a mild chlorotic spot on systemic leave, compared with Fny-CMV. To delimit the sequence of RNA3 affected the pathology, various RNA3 chimeras were constructed between two strains of CMV. The symptom determinants of F1F2L3-CMV were mapped to the positions amino acid 234, 239, and 250 in 3a movement protein (MP). RNA3 chimeras changed the sequences encoding three amino acids were resulted in alteration of systemic symptom.

• Proceedings of the Korean Society of Developmental Biology Conference
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• 2003.10a
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• pp.121-121
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• 2003

The standard protocol for the production of transgenic mouse from ES-injected embryo has to process via chimera producing and several times breeding steps, In contrast, tetraploid-ES cell complementation method allows the immediate generation of targeted murine mutants from genetically modified ES cell clones. The advantage of this advanced technique is a simple and efficient without chimeric intermediates. Recently, this method has been significantly improved through the discovery that ES cells derived from hybrid strains support the development of viable ES mice more efficiently than inbred ES cells do. Therefore, the objective of this study was to generate transgenic mice overexpressing human resistin gene by using tetrapioid-ES cell complementation method. Human resistin gene was amplified from human fetal liver cDNA library by PCR and cloned into pCR 2.1 TOPO T-vector and constructed in pCMV-Tag4C vector. Human resistin mammalian expression plasmid was transfected into D3-GL ES cells by lipofectamine 2000, and then after 8~10 days of transfection, the human resistin-expressing cells were selected with G418. In order to produce tetraploid embryos, blastomeres of diploid embryos at the two-cell stage were fused with two times of electric pulse using 60 V 30 $\mu$sec. (fusion rate : 93.5%) and cultured upto the blastocyst stage (development rate : 94.6%). The 15~20 previously G418-selected ES cells were injected into tetraploid blastocysts, and then transferred into the uterus of E2.5d pseudopregnant recipient mice. To investigate the gestation progress, two El9.5d fetus were recovered by Casarean section and one fetus was confirmed to contain human resistin gene by genomic DNA-PCR. Therefore, this finding demonstrates that tetraploid-ES mouse technology can be considered as a useful tool to produce transgenic mouse for the rapid analysis of gene function in vivo.