Read by QxMD icon Read

Bok Luel Lee

Muhammad Naeem, Junhwan Bae, Murtada A Oshi, Min-Soo Kim, Hyung Ryong Moon, Bok Luel Lee, Eunok Im, Yunjin Jung, Jin-Wook Yoo
Background: Colon-targeted oral nanoparticles (NPs) have emerged as an ideal, safe, and effective therapy for ulcerative colitis (UC) owing to their ability to selectively accumulate in inflamed colonic mucosa. Cyclosporine A (CSA), an immunosuppressive agent, has long been used as rescue therapy in severe steroid-refractory UC. In this study, we developed CSA-loaded dual-functional polymeric NPs composed of Eudragit® FS30D as a pH-sensitive polymer for targeted delivery to the inflamed colon, and poly(lactic-co-glycolic acid) (PLGA) as a sustained-release polymer...
2018: International Journal of Nanomedicine
Seung Ah Lee, Seong Han Jang, Byung Hyun Kim, Toshio Shibata, Jinwook Yoo, Yunjin Jung, Shun-Ichiro Kawabata, Bok Luel Lee
The biochemical characterization of virulence factors from entomopathogenic bacteria is important to understand entomopathogen-insect molecular interactions. Pseudomonas entomophila is a typical entomopathogenic bacterium that harbors virulence factors against several insects. However, the molecular actions of these factors against host innate immune responses are not clearly elucidated. In this study, we observed that bean bugs (Riptortus pedestris) that were injected with P. entomophila were highly susceptible to this bacterium...
April 2018: Developmental and Comparative Immunology
Jiyeun Kate Kim, Ho Am Jang, Min Seon Kim, Jae Hyun Cho, Junbeom Lee, Flaviana Di Lorenzo, Luisa Sturiale, Alba Silipo, Antonio Molinaro, Bok Luel Lee
Lipopolysaccharide, the outer cell-wall component of Gram-negative bacteria, has been shown to be important for symbiotic associations. We recently reported that the lipopolysaccharide O-antigen of Burkholderia enhances the initial colonization of the midgut of the bean bug, Riptortus pedestris However, the midgut-colonizing Burkholderia symbionts lack the O-antigen but display the core oligosaccharide on the cell surface. In this study, we investigated the role of the core oligosaccharide, which directly interacts with the host midgut, in the Riptortus-Burkholderia symbiosis...
November 24, 2017: Journal of Biological Chemistry
Kyoung-Eun Park, Seong Han Jang, Junbeom Lee, Seung Ah Lee, Yoshitomo Kikuchi, Young-Su Seo, Bok Luel Lee
Recently, we have reported the structural determination of antimicrobial peptides (AMPs), such as riptocin, rip-defensin, and rip-thanatin, from Riptortus pedestris. However, the biological roles of AMPs in the host midgut remain elusive. Here, we compared the expression levels of AMP genes in apo-symbiotic insects with those of symbiotic insects. Interestingly, the expression level of rip-thanatin was only significantly increased in the posterior midgut region of symbiotic insects. To further determine the role of rip-thanatin, we checked antimicrobial activity in vitro...
September 14, 2017: Developmental and Comparative Immunology
Ying Jie Ma, Bok Luel Lee, Peter Garred
The complement system is an innate immune defense machinery comprising components that deploy rapid immune responses and provide efficient protection against foreign invaders and unwanted host elements. The complement system is activated upon recognition of pathogenic microorganisms or altered self-cells by exclusive pattern recognition molecules (PRMs), such as collectins, ficolins and pentraxins. Recent accumulating evidence shows that the different classes of effector PRMs build up a co-operative network and exert synergistic effects on complement activation...
April 21, 2017: Experimental & Molecular Medicine
Seong Han Jang, Ho Am Jang, Junbeom Lee, Jong Uk Kim, Seung Ah Lee, Kyoung-Eun Park, Byung Hyun Kim, Yong Hun Jo, Bok Luel Lee
Five genes encoding PhaP family proteins and one phaR gene have been identified in the genome of Burkholderia symbiont strain RPE75. PhaP proteins function as the surface proteins of polyhydroxyalkanoate (PHA) granules, and the PhaR protein acts as a negative regulator of PhaP biosynthesis. Recently, we characterized one phaP gene to understand the molecular cross talk between Riptortus insects and Burkholderia gut symbionts. In this study, we constructed four other phaP gene-depleted mutants (Δ phaP1 , Δ phaP2 , Δ phaP3 , and Δ phaP4 mutants), one phaR gene-depleted mutant, and a phaR -complemented mutant (Δ phaR/phaR mutant)...
June 1, 2017: Applied and Environmental Microbiology
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...
April 2017: 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
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"