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Bok Luel Lee

Jun Beom Lee, Kyoung-Eun Park, Seung Ah Lee, Seong Han Jang, Ho Jeong Eo, Ho Am Jang, Chan-Hee Kim, Tsubasa Ohbayashi, Yu Matsuura, Yoshitomo Kikuchi, Ryo Futahashi, Takema Fukatsu, Bok Luel Lee
Recent studies have suggested that gut symbionts modulate insect development and reproduction. However, the mechanisms by which gut symbionts modulate host physiologies and the molecules involved in these changes are unclear. To address these questions, we prepared three different groups of the insect Riptortus pedestris: Burkholderia gut symbiont-colonized (Sym) insects, Burkholderia-non-colonized (Apo) insects, and Burkholderia-depleted (Sym(Burk-)) insects, which were fed tetracycline. When the hemolymph proteins of three insects were analyzed by SDS-PAGE, the hexamerin-α, hexamerin-β and vitellogenin-1 proteins of Sym-adults were highly expressed compared to those of Apo- and Sym(Burk-)-insects...
December 6, 2016: Developmental and Comparative Immunology
Ho Am Jang, Eun Sil Seo, Min Young Seong, Bok Luel Lee
Riptortus pedestris, a common pest in soybean fields, harbors a symbiont Burkholderia in a specialized posterior midgut region of insects. Every generation of second nymphs acquires new Burkholderia cells from the environment. We compared in vitro cultured Burkholderia with newly in vivo colonized Burkholderia in the host midgut using biochemical approaches. The bacterial cell envelope of in vitro cultured and in vivo Burkholderia differed in structure, as in vivo bacteria lacked lipopolysaccharide (LPS) O-antigen...
February 2017: Developmental and Comparative Immunology
Dong Jung Lee, Jun Beom Lee, Ho Am Jang, Dominique Ferrandon, Bok Luel Lee
Recently, our group demonstrated that the bean bug, Riptortus pedestris, is a good experimental symbiosis model to study the molecular cross-talk between the host insect and the gut symbiont. The Burkholderia symbiont is orally acquired by host nymphs from the environment in every generation. However, it is still unclear how Riptortus specifically interacts with entomopathogens that are abundant in the environmental soil. In preliminary experiments, we observed that a potent entomopathogen, Serratia marcescens, can colonize the midgut of Riptortus insects and was recovered from the midgut when Serratia cells were orally administered, suggesting that this pathogenic bacterium can escape host immune defenses in the salivary fluid...
February 2017: Developmental and Comparative Immunology
Kenji Kurokawa, Kazue Takahashi, Bok Luel Lee
Staphylococcus aureus is a Gram-positive bacterial pathogen that is decorated by glycopolymers, including wall teichoic acid (WTA), peptidoglycan, lipoteichoic acid, and capsular polysaccharides. These bacterial surface glycopolymers are recognized by serum antibodies and a variety of pattern recognition molecules, including mannose-binding lectin (MBL). Recently, we demonstrated that human serum MBL senses staphylococcal WTA. Whereas MBL in infants who have not yet fully developed adaptive immunity binds to S...
October 2016: Immunobiology
Jiyeun Kate Kim, Ha Young Park, Bok Luel Lee
Riptortus pedestris harboring Burkholderia symbiont is a useful symbiosis model to study the molecular interactions between insects and bacteria. We recently reported that the lipopolysaccharide O-antigen is absent in the Burkholderia symbionts isolated from Riptortus guts. Here, we investigated the symbiotic role of O-antigen comprehensively in the Riptortus-Burkholderia model. Firstly, Burkholderia mutant strains deficient of O-antigen biosynthesis genes were generated and confirmed for their different patterns of the lipopolysaccharide by electrophoretic analysis...
July 2016: Developmental and Comparative Immunology
Jiyeun Kate Kim, Jun Beom Lee, Ho Am Jang, Yeon Soo Han, Takema Fukatsu, Bok Luel Lee
Valuable insect models have tremendously contributed to our understanding of innate immunity and symbiosis. Bean bug, Riptortus pedestris, is a useful insect symbiosis model due to harboring cultivable monospecific gut symbiont, genus Burkholderia. Bean bug is a hemimetabolous insect whose immunity is not well-understood. However, we recently identified three major antimicrobial peptides of Riptortus and examined the relationship between gut symbiosis and host immunity. We found that the presence of Burkholderia gut symbiont positively affects Riptortus immunity...
November 2016: Developmental and Comparative Immunology
Tsubasa Ohbayashi, Kazutaka Takeshita, Wataru Kitagawa, Naruo Nikoh, Ryuichi Koga, Xian-Ying Meng, Kanako Tago, Tomoyuki Hori, Masahito Hayatsu, Kozo Asano, Yoichi Kamagata, Bok Luel Lee, Takema Fukatsu, Yoshitomo Kikuchi
Symbiosis has significantly contributed to organismal adaptation and diversification. For establishment and maintenance of such host-symbiont associations, host organisms must have evolved mechanisms for selective incorporation, accommodation, and maintenance of their specific microbial partners. Here we report the discovery of a previously unrecognized type of animal organ for symbiont sorting. In the bean bug Riptortus pedestris, the posterior midgut is morphologically differentiated for harboring specific symbiotic bacteria of a beneficial nature...
September 15, 2015: Proceedings of the National Academy of Sciences of the United States of America
Jun Beom Lee, Jin Hee Byeon, Ho Am Jang, Jiyeun Kate Kim, Jin Wook Yoo, Yoshitomo Kikuchi, Bok Luel Lee
We generated a Burkholderia mutant, which is deficient of an N-acetylmuramyl-l-alanine amidase, AmiC, involved in peptidoglycan degradation. When non-motile ΔamiC mutant Burkholderia cells harboring chain form were orally administered to Riptortus insects, ΔamiC mutant cells were unable to establish symbiotic association. But, ΔamiC mutant complemented with amiC gene restored in vivo symbiotic association. ΔamiC mutant cultured in minimal medium restored their motility with single-celled morphology. When ΔamiC mutant cells harboring single-celled morphology were administered to the host insect, this mutant established normal symbiotic association, suggesting that bacterial motility is essential for the successful symbiosis between host insect and Burkholderia symbiont...
September 14, 2015: FEBS Letters
Jong-Ho Lee, Na-Hyang Kim, Volker Winstel, Kenji Kurokawa, Jesper Larsen, Jang-Hyun An, Adnan Khan, Min-Young Seong, Min Ja Lee, Paal Skytt Andersen, Andreas Peschel, Bok Luel Lee
The cell envelopes of many Gram-positive bacteria contain wall teichoic acids (WTAs). Staphylococcus aureus WTAs are composed of ribitol phosphate (RboP) or glycerol phosphate (GroP) backbones substituted with D-alanine and N-acetyl-D-glucosamine (GlcNAc) or N-acetyl-D-galactosamine (GalNAc). Two WTA glycosyltransferases, TarM and TarS, are responsible for modifying the RboP WTA with α-GlcNAc and β-GlcNAc, respectively. We recently reported that purified human serum anti-WTA IgG specifically recognizes β-GlcNAc of the staphylococcal RboP WTA and then facilitates complement C3 deposition and opsonophagocytosis of S...
November 2015: Infection and Immunity
Soohwan Yum, Seongkeun Jeong, Sunyoung Lee, Joon Nam, Wooseong Kim, Jin-Wook Yoo, Min-Soo Kim, Bok Luel Lee, Yunjin Jung
Piceatannol (PCT), an anti-colitic natural product, undergoes extensive Phase II hepatic metabolism, resulting in very low bioavailability. We investigated whether colon-targeted delivery of PCT could enhance anti-colitic effects and how therapeutic enhancement occurred at the molecular level. Molecular effects of PCT were examined in human colon carcinoma cells and inflamed colons. The anti-colitic effects of PCT in a colon-targeted capsule (colon-targeted PCT) were compared with PCT in a gelatin capsule (conventional PCT) in a trinitrobenzene sulfonic acid-induced rat colitis model...
2015: Drug Design, Development and Therapy
Muhammad Naeem, Jiafu Cao, Moonjeong Choi, Woo Seong Kim, Hyung Ryong Moon, Bok Luel Lee, Min-Soo Kim, Yunjin Jung, Jin-Wook Yoo
Current colon-targeted drug-delivery approaches for colitis therapy often utilize single pH-triggered systems, which are less reliable due to the variation of gut pH in individuals and in disease conditions. Herein, we prepared budesonide-loaded dual-sensitive nanoparticles using enzyme-sensitive azo-polyurethane and pH-sensitive methacrylate copolymer for the treatment of colitis. The therapeutic potential of the enzyme/pH dual-sensitive nanoparticles was evaluated using a rat colitis model and compared to single pH-triggered nanoparticles...
2015: International Journal of Nanomedicine
Jiyeun Kate Kim, Jun Beom Lee, Ye Rang Huh, Ho Am Jang, Chan-Hee Kim, Jin Wook Yoo, Bok Luel Lee
The relation between gut symbiosis and immunity has been reported in various animal model studies. Here, we corroborate the effect of gut symbiont to host immunity using the bean bug model. The bean bug, Riptortus pedestris, is a useful gut symbiosis model due to the monospecific gut symbiont, genus Burkholderia. To examine the effect of gut symbiosis to host immunity, we generated the gut symbiont-harboring (symbiotic) insect line and the gut symbiont-lacking (aposymbiotic) insect line. Upon bacterial challenges, the symbiotic Riptortus exhibited better survival than aposymbiotic Riptortus...
November 2015: Developmental and Comparative Immunology
Jin Hee Byeon, Eun Sil Seo, Jun Beom Lee, Min Ja Lee, Jiyeun Kate Kim, Jin Wook Yoo, Yunjin Jung, Bok Luel Lee
Because gut symbiotic bacteria affect host biology, host insects are expected to evolve some mechanisms for regulating symbiont population. The bean bug, Riptortus pedestris, harbors the Burkholderia genus as a gut symbiont in the midgut organ, designated as the M4 region. Recently, we demonstrated that the lysate of M4B, the region adjacent to M4, harbors potent antibacterial activity against symbiotic Burkholderia but not to cultured Burkholderia. However, the bona fide substance responsible for observed antibacterial activity was not identified in the previous study...
November 2015: Developmental and Comparative Immunology
Jiyeun Kate Kim, Dae Woo Son, Chan-Hee Kim, Jae Hyun Cho, Roberta Marchetti, Alba Silipo, Luisa Sturiale, Ha Young Park, Ye Rang Huh, Hiroshi Nakayama, Takema Fukatsu, Antonio Molinaro, Bok Luel Lee
The molecular characterization of symbionts is pivotal for understanding the cross-talk between symbionts and hosts. In addition to valuable knowledge obtained from symbiont genomic studies, the biochemical characterization of symbionts is important to fully understand symbiotic interactions. The bean bug (Riptortus pedestris) has been recognized as a useful experimental insect gut symbiosis model system because of its cultivatable Burkholderia symbionts. This system is greatly advantageous because it allows the acquisition of a large quantity of homogeneous symbionts from the host midgut...
August 21, 2015: Journal of Biological Chemistry
Hasan Nurhasni, Jiafu Cao, Moonjeong Choi, Il Kim, Bok Luel Lee, Yunjin Jung, Jin-Wook Yoo
Nitric oxide (NO)-releasing nanoparticles (NPs) have emerged as a wound healing enhancer and a novel antibacterial agent that can circumvent antibiotic resistance. However, the NO release from NPs over extended periods of time is still inadequate for clinical application. In this study, we developed NO-releasing poly(lactic-co-glycolic acid)-polyethylenimine (PEI) NPs (NO/PPNPs) composed of poly(lactic-co-glycolic acid) and PEI/diazeniumdiolate (PEI/NONOate) for prolonged NO release, antibacterial efficacy, and wound healing activity...
2015: International Journal of Nanomedicine
Young-Sik Sohn, Ho-Chul Shin, Wei Sun Park, Jianning Ge, Chan-Hee Kim, Bok Luel Lee, Won Do Heo, Jae U Jung, Daniel John Rigden, Byung-Ha Oh
Legionella pneumophila, a human intracellular pathogen, encodes about 290 effector proteins that are translocated into host cells through a secretion machinery. Some of these proteins have been shown to manipulate or subvert cellular processes during infection, but functional roles of a majority of them remain unknown. Lpg0393 is a newly identified Legionella effector classified as a hypothetical protein. Through X-ray crystallographic analysis, we show that Lpg0393 contains a Vps9-like domain, which is structurally most similar to the catalytic core of human Rabex-5 that activates the endosomal Rab proteins Rab5, Rab21 and Rab22...
2015: PloS One
Jiyeun Kate Kim, Bok Luel Lee
Symbiotic bacteria are common in insects and intimately affect the various aspects of insect host biology. In a number of insect symbiosis models, it has been possible to elucidate the effects of the symbiont on host biology, whereas there is a limited understanding of the impact of the association on the bacterial symbiont, mainly due to the difficulty of cultivating insect symbionts in vitro. Furthermore, the molecular features that determine the establishment and persistence of the symbionts in their host (i...
January 2015: Archives of Insect Biochemistry and Physiology
Bok Luel Lee, Shun-ichiro Kawabata, Chengshu Wang, Yonggyun Kim
No abstract text is available yet for this article.
January 2015: Archives of Insect Biochemistry and Physiology
Hamisi Tindwa, Yong Hun Jo, Bharat Bhusan Patnaik, Mi Young Noh, Dong Hyun Kim, Iksoo Kim, Yeon Soo Han, Yong Seok Lee, Bok Luel Lee, Nam Jung Kim
Macroautophagy (autophagy) is an evolutionarily conserved catabolic process involved in physiological and developmental processes including cell survival, death, and innate immunity. Homologues of most of 36 originally discovered autophagy-related (ATG) genes in yeast have been characterized in higher eukaryotes including insects. In this study, the homologues of ATG3 (TmATG3) and ATG5 (TmATG5) were isolated from the coleopteran beetle, Tenebrio molitor by expressed sequence tag and RNAseq approaches. The cDNA of TmATG3 and TmATG5 comprise open-reading frame sizes of 963 and 792 bp encoding polypeptides of 320 and 263 amino acid residues, respectively...
January 2015: Archives of Insect Biochemistry and Physiology
Su-Jin Park, Soo-Kyoung Kim, Yong-In So, Ha-Young Park, Xi-Hui Li, Doo Hwan Yeom, Mi-Nan Lee, Bok-Luel Lee, Joon-Hee Lee
In Pseudomonas aeruginosa, quorum sensing (QS) plays an essential role in pathogenesis and the QS response controls many virulence factors. Using a mealworm, Tenebrio molitor as a host model, we found that Protease IV, a QS-regulated exoprotease of P. aeruginosa functions as a key virulence effector causing the melanization and death of T. molitor larvae. Protease IV was able to degrade zymogens of spätzle processing enzyme (SPE) and SPE-activating enzyme (SAE) without the activation of the antimicrobial peptide (AMP) production...
December 2014: Molecular Microbiology
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