• 제목/요약/키워드: Human Monoclonal Antibodies

검색결과 130건 처리시간 0.024초

인체 혈장 중 칼시트리올의 효소면역 분석법 검증 및 단회투여 후 약물동태 연구 (Validation of an Enzyme-Immunoassay for Calcitriol in Human Plasma and Evaluation of Its Pharmacokinetics after Single-dose in Korean Volunteers)

  • 김예태;진수언;김현기;신백기;정의현;김종국;박정숙
    • Journal of Pharmaceutical Investigation
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    • 제39권4호
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    • pp.309-314
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    • 2009
  • An enzyme immunoassay (EIA) was validated for quantitation of cacitriol in human plasma. Calcitriol was immunoextracted with immunocapsules, which contain monoclonal antibodies to calcitriol linked to solid phase particles in suspension with a vitamin D binding protein inhibitor. Calcitrol was eluated and the eluates were evaporated under a gentle stream of nitrogen gas. The absorbance of analytes was determined using a microplate reader (reference wavelength 650 nm; measurement wavelength 450 nm). The method was specific and sensitive enough to detect as low as 6.5 pmol/L of calcitriol. Linear calibration range was 6.5-491 pmol/L with correlation coefficient greater than 0.99. The overall accuracy was in the range of 83.8 to 111.2% and precision C.V. (%) 0.99 to 8.47%. The recovery was approximately 100% and stability was confirmed during storage and sample preparation. The pharmacokinetic parameters were calculated by baseline subtraction because calcitriol is an endogenous material. Following oral dose of calcitriol, the mean AUC$_{24h}$ was 1038${\pm}$539 pmol/Lhr and C$_{max}$ of 128${\pm}$63.1 pmol/L was reached at 3.50${\pm}$1.07 hr. The mean t$_{1/2}$ of calcitriol was 5.13${\pm}$2.10 hr. The present EIA method was successfully applied to study bioavailability after oral administration of 2 ${\mu}$g of calcitriol in healthy Korean subjects.

Inhibitory Effect of a Phosphatidyl Ethanolamine Derivative on LPS-Induced Sepsis

  • Lee, Chunghyun;An, Hyun-Jung;Kim, Jung-In;Lee, Hayyoung;Paik, Sang-Gi
    • Molecules and Cells
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    • 제27권2호
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    • pp.251-255
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    • 2009
  • Sepsis is the leading cause of death in critically ill patients. Today, around 60% of all cases of sepsis are caused by Gram-negative bacteria. The cell wall component lipopolysaccharide (LPS) is the main initiator of the cascade of cellular reactions in Gram-negative infections. The core receptors for LPS are toll-like receptor 4 (TLR4), MD-2 and CD14. Attempts have been made to antagonize the toxic effect of endotoxin using monoclonal antibodies against CD14 and synthetic lipopolysaccharides but there is as yet no effective treatment for septic syndrome. Here, we describe an inhibitory effect of a phosphatidylethanolamine derivative, PE-DTPA (phosphatidylethanolamine diethylenetriaminepentaacetate) on LPS recognition. PE-DTPA bound strongly to CD14 ($K_d$, $9.52{\times}10^{-8}M$). It dose dependently inhibited LPS-mediated activation of human myeloid cells, mouse macrophage cells and human whole blood as measured by the production of tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) and nitric oxide, whereas other phospho-lipids including phosphatidylserine and phosphatidylethanolamine had little effect. PE-DTPA also inhibited transcription dependent on $NF-{\kappa}B$ activation when it was added together with LPS, and it rescued LPS-primed mice from septic death. These results suggest that PE-DTPA is a potent antagonist of LPS, and that it acts by competing for binding to CD14.

Detection of Expressed IL-32 in Human Stomach Cancer Using ELISA and Immunostaining

  • Seo, Eun-Hee;Kang, Jeong-Woo;Kim, Ki-Hong;Cho, Min-Chul;Lee, So-Jung;Kim, Hee-Jong;Kim, Jung-Hee;Kim, Eun-Jin;Park, Dong-Ki;Kim, Soo-Hyun;Choi, Yang-Kyu;Kim, Jin-Man;Hong, Jin-Tae
    • Journal of Microbiology and Biotechnology
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    • 제18권9호
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    • pp.1606-1612
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    • 2008
  • Interleukin (IL)-32 is a recently identified proinflammatory cytokine that is one of the IL-18 inducible genes, and plays an important role in autoimmune and inflammatory diseases. We produced antibodies against IL-32 and studied the expression of IL-32 in human stomach cancer. We detected IL-32 secreted from K-562 cells which were stably transfected with IL-32 and in the sera of stomach cancer patients by a sandwich ELISA using a monoclonal antibody KU32-52 and a polyclonal antibody. In order to optimize a sandwich immunoassay, recombinant IL-32a was added, followed by the addition of a biotinylated KU32-52 into microtiter plate wells precoated with a goat anti-IL-32 antibody. The bound biotinylated KU32-52 was probed with a streptavidin conjugated to HRP. This sandwich ELISA was highly specific and had a minimal detection limit of 80 pg/ml (mean${\pm}$SD of zero calibrator) and measuring up to 3,000 pg/ml. This ELISA showed no cross-reaction with other cytokines such as hIL-1$\alpha$, hIL-1$\beta$, hIL-2, hIL-6, hIL-8, hIL-10, hIL-18, and hTNF-$\alpha$. Intra-assay coefficients of variation were 18.5% to 4.6% (n=10), and inter-assay coefficients were 23% to 9% (n=10). The average IL-32 level in the sera of 16 stomach cancer patients (189 pg/ml) was higher than that of 12 healthy control men (109 pg/ml). Our results indicate that serum IL-32 level can be detected by using an established ELISA, and that this immunoassay and mAb KU32-09 specific for immunohistochemistry can be used in the detection of expressed and secreted IL-32 in stomach cancer patients.

Generation and Characterization of Monoclonal Antibodies to the Ogawa Lipopolysaccharide of Vibrio cholerae O1 from Phage-Displayed Human Synthetic Fab Library

  • Kim, Dain;Hong, Jisu;Choi, Yoonjoo;Han, Jemin;Kim, Sangkyu;Jo, Gyunghee;Yoon, Jun-Yeol;Chae, Heesu;Yoon, Hyeseon;Lee, Chankyu;Hong, Hyo Jeong
    • Journal of Microbiology and Biotechnology
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    • 제30권11호
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    • pp.1760-1768
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    • 2020
  • Vibrio cholerae, cause of the life-threatening diarrheal disease cholera, can be divided into different serogroups based on the structure of its lipopolysaccharide (LPS), which consists of lipid-A, core-polysaccharide and O-antigen polysaccharide (O-PS). The O1 serogroup, the predominant cause of cholera, includes two major serotypes, Inaba and Ogawa. These serotypes are differentiated by the presence of a single 2-O-methyl group in the upstream terminal perosamine of the Ogawa O-PS, which is absent in the Inaba O-PS. To ensure the consistent quality and efficacy of the current cholera vaccines, accurate measurement and characterization of each of these two serotypes is highly important. In this study, we efficiently screened a phage-displayed human synthetic Fab library by bio-panning against Ogawa LPS and finally selected three unique mAbs (D9, E11, and F7) that specifically react with Ogawa LPS. The mAbs bound to Vibrio cholerae vaccine in a dose-dependent fashion. Sequence and structure analyses of antibody paratopes suggest that IgG D9 might have the same fine specificity as that of the murine mAbs, which were shown to bind to the upstream terminal perosamine of Ogawa O-PS, whereas IgGs F7 and E11 showed some different characteristics in the paratopes. To our knowledge, this study is the first to demonstrate the generation of Ogawa-specific mAbs using phage display technology. The mAbs will be useful for identification and quantification of Ogawa LPS in multivalent V. cholerae vaccines.

마우스 EAE, GVHD 질환에서 CTLA4Ig 융합단백의 면역치료 효과 (Immunotherapeutic Effects of CTLA4Ig Fusion Protein on Murine EAE and GVHD)

  • 장성옥;홍수종;조훈식;정용훈
    • IMMUNE NETWORK
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    • 제3권4호
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    • pp.302-309
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    • 2003
  • Background: CTLA4 (CD152), which is expressed on the surface of T cells following activation, has a much higher affinity for B7 molecules comparing to CD28, and is a negative regulator of T cell activation. In contrast to stimulating and agonistic capabilities of monoclonal antibodies specific to CTLA-4, CTLA4Ig fusion protein appears to act as CD28 antagonist and inhibits in vitro and in vivo T cell priming in variety of immunological conditions. We've set out to confirm whether inhibition of the CD28-B7 costimulatory response using a soluble form of human CTLA4Ig fusion protein would lead to persistent inhibition of alloreactive T cell activation. Methods: We have used CHO-$dhfr^-$ cell-line to produce CTLA4Ig fusion protein. After serum free culture of transfected cell line we purified this recombinant molecule by using protein A column. To confirm characterization of fusion protein, we carried out a series of Western blot, SDS-PAGE and silver staining analyses. We have also investigated the efficacy of CTLA4Ig in vitro such as mixed lymphocyte reaction (MLR) & cytotoxic T lymphocyte (CTL) response and in vivo such as experimental autoimmune encephalomyelitis (EAE), graft versus host disease (GVHD) and skin-graft whether this fusion protein could inhibit alloreactive T cell activation and lead to immunosuppression of activated T cell. Results: In vitro assay, CTLA4Ig fusion protein inhibited immune response in T cell-specific manner: 1) Human CTLA4Ig inhibited allogeneic stimulation in murine MLR; 2) CTLA4Ig prevented the specific killing activity of CTL. In vivo assay, human CTLA4Ig revealed the capacities to induce alloantigen-specific hyporesponsiveness in mouse model: 1) GVHD was efficiently blocked by dose-dependent manner; 2) Clinical score of EAE was significantly decreased compared to nomal control; 3) The time of skin-graft rejection was not different between CTLA4Ig treated and control group. Conclusion: Human CTLA4Ig suppress the T cell-mediated immune response and efficiently inhibit the EAE, GVHD in mouse model. The mechanism of T cell suppression by human CTLA4Ig fusion protein may be originated from the suppression of activity of cytotoxic T cell. Human CTLA4Ig could not suppress the rejection in mouse skin-graft, this finding suggests that other mechanism except the suppression of cytotoxic T cell may exist on the suppression of graft rejection.

Generation, Diversity Determination, and Application to Antibody Selection of a Human Naïve Fab Library

  • Kim, Sangkyu;Park, Insoo;Park, Seung Gu;Cho, Seulki;Kim, Jin Hong;S.Ipper, Nagesh;Choi, Sun Shim;Lee, Eung Suk;Hong, Hyo Jeong
    • Molecules and Cells
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    • 제40권9호
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    • pp.655-666
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    • 2017
  • We constructed a large $na{\ddot{i}}ve$ human Fab library ($3{\times}10^{10}$ colonies) from the lymphocytes of 809 human donors, assessed available diversities of the heavy-chain variable (VH) and ${\kappa}$ light-chain variable (VK) domain repertoires, and validated the library by selecting Fabs against 10 therapeutically relevant antigens by phage display. We obtained a database of unique 7,373 VH and 41,804 VK sequences by 454 pyrosequencing, and analyzed the repertoires. The distribution of VH and VK subfamilies and germline genes in our antibody repertoires slightly differed from those in earlier published natural antibody libraries. The frequency of somatic hypermutations (SHMs) in heavy-chain complementarity determining region (HCDR)1 and HCDR2 are higher compared with the natural IgM repertoire. Analysis of position-specific SHMs in CDRs indicates that asparagine, threonine, arginine, aspartate and phenylalanine are the most frequent non-germline residues on the antibody-antigen interface and are converted mostly from the germline residues, which are highly represented in germline SHM hotspots. The amino acid composition and length-dependent changes in amino acid frequencies of HCDR3 are similar to those in previous reports, except that frequencies of aspartate and phenylalanine are a little higher in our repertoire. Taken together, the results show that this antibody library shares common features of natural antibody repertoires and also has unique features. The antibody library will be useful in the generation of human antibodies against diverse antigens, and the information about the diversity of natural antibody repertoires will be valuable in the future design of synthetic human antibody libraries with high functional diversity.

사람 연골하골 중간엽 줄기세포의 효율적인 골형성 유도 (Induction of Effective Osteogenesis by Mesenchymal Stem Cells from the Human Subchondral Bone)

  • 허정은;조윤제;유명철;백용현;이재동;최도영;박동석
    • Journal of Acupuncture Research
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    • 제23권5호
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    • pp.69-77
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    • 2006
  • Background : Mesenchymal stem cells (MSCs) are present in most of the tissue matrix, taking part in their regeneration when injury or damage occurs. The aim of this study was to investigate the presence of cells with pluripotential characteristics in human subchondral bone and the capacity of these cells to differentiate to osteoblast. Methods : Human subchondral bone were digested with collagenase. Isolated cells were cultured with a-MEM, 15% FBS, 10-8M dexamethasone and 50 ng/mL ascoric acid. Cells from 0 day(isolated cells), 7 day (first subculture) and 14 days (third subculture) were used to carry out phenotypic characterization experiments flowcytometry analysis with 11 monoclonal antibodies) and osteogenic differentiation experiments. Osteogenic differentiation of cells was assessment by quantification of bone extracellular matrix components by following analysis: alkaline phosphatase(ALP) stains to detect ALP activity, RT-PCR and western blot to detect osteocalcin (OCN), osteopontin (OPN) and type I collagen(Col I), and Alizarin red stains to detect calcium deposition. Results : Flowcytometry analyses showed that in our population more than 98% of cells were positive for MSC markers: SH-2(CD105, 99%), CD29 (95%), CD73 (95%). Cells were negative for hematopoietic markers (CD11b, CD34, and CD45). Furthermore, cells showed positive stain to multipotent markers such as CDl17 (c-kit) (15.1%), and CD166 (74.9%), and cell adhesion molecules such as CD54 (78.1%) and CD106 (63.5%). The osteogenic specific marker analyses showed that the culture of these cells for 7 and 14 days stimulates ALP, OCN, OPN and Col I synthesis by RT-PCR and Western blot analysis. Also, after 14 days in the culture of MSCs induces mineralization by Arizarin red stain. Conclusion : In this work, we demonstrated a new and efficient method for osteoblastic differentiation of human subchondral bone stem cells. As MSCs takes part in reparative processes of adult tissues, these cells could play an important role in osteogenesis.

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Effects of in vitro vitamin D treatment on function of T cells and autophagy mechanisms in high-fat diet-induced obese mice

  • Kang, Min Su;Park, Chan Yoon;Lee, Ga Young;Cho, Da Hye;Kim, So Jeong;Han, Sung Nim
    • Nutrition Research and Practice
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    • 제15권6호
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    • pp.673-685
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    • 2021
  • BACKGROUND/OBJECTIVES: Obesity is associated with the impaired regulation of T cells characterized by increased numbers of Th1 and Th17 cells and the dysregulation of vitamin D metabolism. Both obesity and vitamin D have been reported to affect autophagy; however, a limited number of studies have investigated the effects of vitamin D on T cell autophagy in obese mice. Therefore, we aimed to determine whether in vitro treatment with vitamin D affects the proliferation, function, and autophagy of T cells from obese and control mice. MATERIALS/METHODS: Five-week-old male C57BL/6 mice were fed control or high-fat diets (10% or 45% kcal fat: CON or HFDs, respectively) for 12 weeks. Purified T cells were stimulated with anti-CD3 and anti-CD28 monoclonal antibodies and cultured with either 10 nM 1,25(OH)2D3 or 0.1% ethanol (vehicle control). The proliferative response; expression of CD25, Foxp3, RORγt, and autophagy-related proteins (LC3A/B, SQSTM1/P62, BECLIN-1, ATG12); and the production of interferon (IFN)-γ, interleukin (IL)-4, IL-17A, and IL-10 by T cells were measured. RESULTS: Compared with the CON group, T cell proliferation tended to be lower, and the production of IFN-γ was higher in the HFD group. IL-17A production was reduced by 1,25(OH)2D3 treatment in both groups. The LC3 II/I ratio was higher in the HFD group than the CON group, but P62 did not differ. We observed no effect of vitamin D treatment on T cell autophagy. CONCLUSIONS: Our findings suggest that diet-induced obesity may impair the function and inhibit autophagy of T cells, possibly leading to the dysregulation of T cell homeostasis, which may be behind the aggravation of inflammation commonly observed in obesity.

Immunohistochemical Evaluation of Angiogenesis Related Markers in Pyogenic Granuloma of Gingiva

  • Seyedmajidi, Maryam;Shafaee, Shahryar;Hashemipour, Golnarsadat;Bijani, Ali;Ehsani, Hodis
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권17호
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    • pp.7513-7516
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    • 2015
  • Background: Pyogenic granuloma is a common non-neoplastic connective tissue proliferation. ICAM-1 and VCAM-1 are vascular adhesion molecules and CD34 is a marker for evaluation of angiogenesis. The purpose of this study was to compare the immunohistochemical expression of ICAM-1, VCAM-1 & CD34 in oral pyogenic granuloma and normal gingiva. Materials and Methods: This study was performed on thirty five formalin-fixed, paraffin embedded samples of gingival pyogenic granuloma. Also we used thirty five paraffined blocks of normal gingiva as control group which were taken from crown lengthening surgery. We employed immunohistochemistry staining for our prepared microscopic slides using monoclonal mouse anti-human antibodies against ICAM-1 (CD54), VCAM-1 (CD106) and CD34. Slides were examined under light microscope and then the mean amount of stained vessels also known as microvascular density (MVD) in highly vascularized areas (hot spots) was measured. Paired t-test and repeated measures ANOVA were used to compare the difference between quantitative variables and Chi-square test for qualitative variables in different groups. Pearson correlation coefficient was used to compare relations between quantitative variables. P<0.05 was considered significant. Results: The mean of MVD for ICAM-1, VCAM-1 and CD34 was significantly higher in pyogenic granuloma than normal gingiva (p<0.001 & p<0.001 & p<0.001, respectively). Expression of CD34 in pyogenic granuloma was significantly higher than ICAM-1 and VCAM-1 (P<0.001). Besides, expression of ICAM-1 in normal gingiva, was significantly lower than two other markers (p<0.001). Conclusions: Regarding the results, it seems that ICAM-1, VCAM-1 and CD34 are useful biomarkers in evaluation of vascular and inflammatory lesions such as gingival pyogenic granuloma and the results indicate the role of these biomarkers in pathogenesis of oral pyogenic granuloma.

The Clinicopathological and Prognostic Impact of 14-3-3 Protein Isoforms Expression in Human Cholangiocarcinoma by Immunohistochemistry

  • Wu, Qiao;Liu, Chang-Zheng;Tao, Lian-Yuan;Yu, Lan;Liu, Wei;Chen, Song-Sen;He, Xiao-Dong
    • Asian Pacific Journal of Cancer Prevention
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    • 제13권4호
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    • pp.1253-1259
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    • 2012
  • The 14-3-3 proteins are highly conserved, ubiquitous molecules involved in a variety of biologic phenomena, such as cell cycle control, and apoptosis. However, their expression in cholangiocarcinoma has not been previously characterized. In this paper, immunohistochemistry using specific anti-14-3-3 monoclonal antibodies was performed on formalin-fixed;, paraffin embedded archival tissue from 86 patients of cholangiocarcinoma. We also examined the correlation between expression and survival rate and clinicopathologic factors such as tumor location, tumor size, pathologic differentiation, lymphatic permeation, lymph node metastasis, and tumor stage. Positive 14-3-3 proteins expression was observed for 6 isoforms (${\beta}$, ${\sigma}$, ${\gamma}$, ${\theta}$, ${\delta}$, ${\eta}$) of these proteins in 86 patients of cholangiocarcinoma. ${\beta}$ and ${\sigma}$ isoform immunoreactivity was correlated with lymph node metastasis, tumor stage and patients' survival rate. In addition, ${\delta}$ isoform immunoreactivity showed trends with tumor location, tumor size, pathologic differentiation and tumor stage, while the ${\theta}$ isoform was correlated with pathologic differentiation. These results indicated that upregulated expression of some isoforms of 14-3-3 may be a common mechanism for evading apoptosis in cholangiocarcinoma, so that targeting 14-3-3 may be a novel promising strategy for the treatment of this tumor.