• Proceedings of the Korean Biophysical Society Conference
• /
• 2001.06a
• /
• pp.29-29
• /
• 2001

Leukocytes are important elements in the host defense against microbial infections. A variety of antimicrobial peptides named as the cathelicidin family have been identified from leukocytes. PMAP-23 derived from porcine myeloid cells is an antimicrobial peptide belong to the cathelicidin family. PMAP-23 was reported to have potent growth inhibition activity against bacterial and tumor cells with no hemolytic activity.(omitted)

• Journal of Microbiology
• /
• v.35 no.2
• /
• pp.149-151
• /
• 1997

A plasmid vector with combined features of yeast shuttle vector and mammalian expression vector was constructed to facilitate expression of cloned gene in both cell-types. All necessary elements required for plasmid maintenance and selection in E. coli, yeast and mammalian cells were size-economically arranged in this plasmid. The numan cytomegalovirus (CMV) immediate early promoter and yeast GAL1 promoter were sequentially placed in front of the gene to be expressed. The synthetic splicing donor and acceptor sequences were inserted into the immediate upstream and downstream of the GAL1 promotor, allowing the CMV promotor to direct the expression of a given gene in mammalian cell environment by splicing out the interfering GAL1 promotor sequence. When the resulting vector containing LacZ as a gene was introduced into yeast and mammalian cells, both cells efficiently produced .betha.-galactosidase, dimonstrating its dual host usage.

• Korean Journal of Veterinary Research
• /
• v.49 no.2
• /
• pp.167-172
• /
• 2009

Human granulocytic anaplasmosis (HGA) is caused by the obligate intracellular bacterium Anaplasma (A.) phagocytophilum. Natural killer T (NKT) cells are key players in host defense against various microbial infections. We investigated the role of NKT cells in immune response to A. phagocytophilum infection using NKT-knockout ($J\alpha$18-/-) mice. $J\alpha$18-/- and wild-type (WT) mice were infected with low-passage A. phagocytophilum and assayed for hepatic histopathology and cytokine production during 7 days post-infection. Compared to WT controls, the infected $J\alpha$18 -/- mice had much less histopathologic lesions and less apoptosis through day 7, and lower concentrations of ${IFN\gamma}$ and IL- 12, but not of IL-10. This result suggests that NKT cells are major components in the pathogenesis of HGA.

• Biomedical Science Letters
• /
• v.24 no.3
• /
• pp.175-182
• /
• 2018

Aspergillosis is a life-threatening disease in individuals with compromised immune systems. Fungal invasion is a highly critical process during host cellular infection. Several papers have reported that transcription factors are responsible for the infection process. To investigate what transcription factors are involved in the process in an effort to inhibit fungal infection into cells, I checked the surfactant protein family and PU.1 transcription factor levels in A549 cells infected with A. fumigatus conidia. PU.1 and surfactant protein-D levels were reduced in cells infected with fungal conidia. I then observed an increase in surfactant protein-D on PU.1-overexpressed cells. Infection of A. fumigatus conidia was decreased in PU.1-overexpressed cells, whereas the suppression of PU.1 did not lead to any changes in cases of A. fumigatus conidia infection. These results indicate that PU.1 inhibits the infection of A. fumigatus conidia via the expression of surfactant protein-D, suggesting that PU.1 is a key transcription factor for protection against A. fumigatus invasion.

• Korean Journal of Environmental Biology
• /
• v.40 no.3
• /
• pp.301-306
• /
• 2022

The vegetative and reproductive morphology of some parasitic Janczewskia Solms-Laubach species including the type species was examined based on specimens collected from various localities around the world. In J. gardneri Setchell et Guernsey on Osmundea spectabilis (Postels et Ruprecht) Nam from California, secondary pit connections are not found between epidermal cells and vegetative axial cells have two pericentral cells. As its host, J. gardneri also has a typical filament type male structure in an apical urn-shaped pit of branches rather than the trichoblast type in other species including the type J. verruciformis Solms-Laubach and tetrasporangial origin of epidermal cells rather than pericentral cells. These significant differences between the species suggest that J. gardneri should be separated from the genus Janczewskia. Based on this morphological data, the section Heterojanczewskia Setchell including J. gardneri, together with an emendation of the generic delineation of Janczewskia, is elevated to the genus level. Relevant nomenclatural changes for some Janczewskia species are also included here.

• IMMUNE NETWORK
• /
• v.4 no.4
• /
• pp.205-215
• /
• 2004

In the early host defense system, effector function of natural killer (NK) cells results in natural killing against target cells such as microbe-infected, malignant, and certain allogenic cells without prior stimulation. NK cell cytotoxicity is selectively regulated by homeostatic prevalence between a repertoire of both activating and inhibitory receptors, and the discrimination of untransformed cells is achieved by recognition of major histocompatibility complex (MHC) class I alleles through inhibitory signals. Although it is well known that the bipotential T/NK progenitors are derived from the common precusor, functional mechanisms in terms of the development of NK cells remain to be further investigated. NK cells are mainly involved in innate immunity, but recent studies have been reported that they also play a critical role in adaptive immune responses through interaction with dendritic cells (DC). This interaction will provide effector functions and development of NK cells, and elucidation of its precise mechanism may lead to therapeutic strategies for effective treatment of several immune diseases.

• Parasites, Hosts and Diseases
• /
• v.35 no.2
• /
• pp.79-86
• /
• 1997

Toxoplasmn gonnii, an intracellular protozoan infecting many kinds of eukaryotic cells, has been used to experimentally infect macrophages, epithelial cells, fibroblasts, and various cancer cells, but rarely T and B Iymphocytes or granulocytes. The present study was performed to determine the susceptibility of murine (BALB/c or CBA) splenic T and B llrnphocytes, and granulocytes to infection trio T. gondii RH tachyzoites. The ultrastructure of the infected host cells was observed by TEM, and the degree of intracellular parasite proliferation was quantified using 3H-uracil uptake assay. At 24 hrs post-culture, the host cell cytoplasm was found to contain 1 or 2, or a maximum of 7-8 tachyzoites. Infected T Iymphocytes demonstrated a peripherally displaced nucleus, a parasitophorous vacuole enveloping the parasite, and an increased number of mitochondria. In B Iymphocytes infected with tachyzoites, RER was not well developed compared to uninfected B Iymphocytes. Uninfected granulocytes contained many electron dense granules, but T. gondii-infected granulocytes demonstrated a decreased number of granules. Based on the 3H-uracil uptake assay. the susceptibility of T and B Iymphocytes, and granulocytes, to infection with T. gonnii tachyzoites was fairly high irrespective of cell type and strain of mouse. This strongly suggests deterioration in the functioning of infected host immune cells.

• Journal of Microbiology and Biotechnology
• /
• v.16 no.10
• /
• pp.1485-1490
• /
• 2006

In this study, comparative replicational properties of Hyphantria cunea nucleopolyhedrovirus (HycuNPV) in Lymantria dispar (IPLB-LdElta) and Spodoptera frugiperda (IPLB-Sf21) cell lines were investigated. Our microscopic observations showed that cytopathic effects (CPEs) in LdElta cells appeared 12 h later than those in Sf21 cells. Whereas polyhedral inclusion bodies (PIBs) formed at 48 h postinfection (p.i.) in LdElta cells, it formed at 36 h p.i. in Sf21 cells. Extracellular virus production determined according to the 50% tissue culture infective dose ($TCID_{50}$) method in LdElta cells started about 12 h later when compared with Sf21 cells. Titers of extracellular virus in LdElta and Sf21 cells were calculated as $1.77{\times}10^9$ plaque forming units (PFU)/ml and $5.6{\times}10^9PFU/ml$, respectively, at 72 h p.i. We also showed that viral DNA replication began at 12 h p.i. in both cell lines. Viral protein synthesis was determined by SDS-polyacrylamide gel electrophoresis (PAGE) and polyhedrin synthesis was observed at 12 h p.i. in both cell lines. The results indicate that while the synthesis of macromolecules is 12 h later and production of extracellular virus is almost 3-fold lower in LdElta cells compared with those in Sf21 cells, the LdElta cell line is still a productive cell line for infection of HycuNPV.

• Animal cells and systems
• /
• v.2 no.4
• /
• pp.415-418
• /
• 1998

Two leaf-miner flies, Phytomyza japonica and Phytomyza yasumastui, are newly added to the Korean fauna. A key to Korean species of the genus Phytomyza is given. The known host plants and domestic localities are included.

• Proceedings of the Korean Society of Sericultural Science Conference
• /
• 2004.10a
• /
• pp.52-53
• /
• 2004