• Korean Journal of Veterinary Service
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• v.18 no.1
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• pp.1-21
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• 1995

To elucidate pathogenesis of bovine leukemia virus(BLV) in Korean native goats, the goats experimentally infected with BLV were studied especially for the aspects of infectivity and hematological changes. The experimental goats were examined for 27 months by agar-gel immunodiffusion(AGID) test and syncytium formation assay. During this period, changes of total leucocyte, absolute Iymphocyte and atypical Iymphocyte were examined, and the distribution of surface immunoglobulin ( sIg ) -bearing cells and rosette forming cell (RFC) in the peripheral Iymphocyte were also investigated. By indirect immunofluorescence (IFA) and complement dependent antibody cytotoxicity (CDAC) assay using monoclonal antibody(Mab) against bovine leukosis tumor-associated anti-gen(BL-TAA), changes of BL-TAA positive Iymphocyte in peripheral blood were measured. The results obtained through the experiment were summarized as follows. 1. Antibody titers were measured by AGID using gP51 and P24 antigens. The animals were serologically converted at 2 months post-inoculation(pi) in gP51 antigen, whereas sero-converted at 4 months pi in P24 antigen. In comparison with antibody titers for gP51, P24 antigen showed lower titers throughout the trial period. 2. The peripheral lymphocytes from all of the infected goats, as co-cultivated with F8l cells manifested syncytial formation at 4 months pi. 3. On counting total leucocyte, Iymphocyte and atypical Iymphocyte, two out of four infected goats showed normal distribution, while No 2 of the remaining two revealed temporal and No 3, Persistant increasing number of the cells. 4. The optimal condition of rosette formation of the peripheral Iymphocyte of normal Korean native goats was shown in the sheep erythrocyte treated with 0.1M AET for 30 nun at $37^{\circ}C$. When the Iymphocytes were treated in nylon wool column, the number of sIg-bear-ing cell were increased in the nylon wool adherent cells, but RFC was increased in the non-adherent cells. Of the infected goats, No 2 and No 3 showed significantly increasing number of sIg-bearing cells at 18 months pi. 5. The Iymphocytes of No 2 and No 3 goats reacted positively in IFA using Mab against BL-TAA at 12 months pi and 18 months pi, respectively. In CDAC test, all of four infected goats revealed positive reaction at 24 months pi. The higher positive rates were observed in No 2 and No 3 as compared with the remainders.

• Applied Chemistry for Engineering
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• v.29 no.1
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• pp.97-102
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• 2018

In this work, the surface of gold nanoparticles (AuNPs) was modified with small molecules including mercaptoundecanoic acid (MUA) and L-lysine for the development of highly sensitive lateral flow (LF) sensors. Uniformly sized AuNps were synthesized by a modified Turkevich-Frens method, showing an average size of $16.7{\pm}2.1nm$. Functionalized AuNPs were then characterized by transmission electron microscopy, UV-vis spectroscopy, X-ray photoelectron spectroscopy, and Fourier transform infrared spectroscopy. The stable conjugation of AuNPs and antibodies was obtained at pH 7.07 and the antibody concentration of $10{\mu}g/mL$. The functionalized AuNP-based LF sensor exhibited lower detection limit of 10 ng/mL for hepatitis B surface antigens than that of using the bare AuNP-based LF sensor (100 ng/mL).

• Korean Journal of Microbiology
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• v.38 no.1
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• pp.38-44
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• 2002

Pneumococcal surfacce protein A (PspA) is an important virulence factor and an antigenically variable surface protein of the pneumococci. To purify the PspA from S. pneumoniae KNIH1156 , a clinical isolate (type 19F), we have taken advantage of the fact that PspA is released from the surface of pneumococci into the medium by growing in a CDM-ET medium and PspA is capable of binding human lactoferrin, the iron carrier protein. PspA of S. pneumoniae KNIH1156 was purified from culture supernatant by human lactoferrin (hLf) affinity chromatography. The purified PspA was confirmed with anti-PspA antiserum and also had the binding capacity to hLf specifically. To determine whether the purified PspA could elicit protection in mice against pneumococcal inflection, we immunized the mice with purified PspA and subsequently challenged with S. pneumoniae KNIH1156. Immunization with purified PspA protected mice from 500 times the $LD^{50}$ of S. pneumoniae KNIH1156. Therefore, it has been shown that purified PspA fromS. pneumoniae KNIH1156 (type 19F) is a protective immunogen.

• Journal of Sensor Science and Technology
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• v.22 no.2
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• pp.144-149
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• 2013

In this research, we developed a biosensor to detect lung cancer-specific biomarker using Anodic Aluminum Oxide (AAO) chip based on interference and nano surface plasmon resonance (nanoSPR). The nano-porous AAO chip was fabricated $2{\mu}m$ of pore-depth by two-step anodizing method for surface uniformity. NanoSPR has sensitivity to the refractive index (RI) of the surrounding medium and also provides simple and label-free detection when specific antibodies are immobilized to the Au-deposited surface of nano-porous AAO chip. To detect the lung cancer-specific biomarker, antibodies were immobilized on the surface of the chip by Self Assembled Monolayer (SAM) method. Since then lung cancer-specific biomarker was applied atop the antibodies immobilized layer. The specific reaction of the antigen-antibody contributed to the change in the refractive index that cause shift of resonance spectrum in the interference pattern. The Limit of Detection (LOD) was 1 fg/ml by using our nano-porous AAO biosensor chip.

• Journal of Microbiology and Biotechnology
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• v.24 no.3
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• pp.408-420
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• 2014

Yeast surface-displayed antibody libraries provide an efficient and quantitative screening resource for given antigens, but suffer from typically modest library sizes owing to low yeast transformation efficiency. Yeast mating is an attractive method for overcoming the limit of yeast transformation to construct a large, combinatorial antibody library, but the optimal conditions have not been reported. Here, we report a large synthetic human Fab (antigen binding fragment) yeast surface-displayed library generated by stepwise optimization of yeast mating conditions. We first constructed HC (heavy chain) and LC (light chain) libraries, where all of the six CDRs (complementarity-determining regions) of the variable domains were diversified mimicking the human germline antibody repertoires by degenerate codons, onto single frameworks of VH3-23 and $V{\kappa}1$-16 germline sequences, in two haploid cells of opposite mating types. Yeast mating conditions were optimized in the order of cell density, media pH, and cell growth phase, yielding a mating efficiency of ~58% between the two haploid cells carrying HC and LC libraries. We constructed two combinatorial Fab libraries with CDR-H3 of 9 or 11 residues in length with colony diversities of more than $10^9$ by one round of yeast mating between the two haploid HC and LC libraries, with modest diversity sizes of ${\sim}10^7$. The synthetic human Fab yeast-displayed libraries exhibited relative amino acid compositions in each position of the six CDRs that were very similar to those of the designed repertoires, suggesting that they are a promising source for human Fab antibody screening.

• Journal of Life Science
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• v.16 no.6
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• pp.904-910
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• 2006

Dendritic cells (DCs) are the only antigen presenting cells (APCs) capable of initiating immune responses, which is crucial for priming the specific cytotoxic T lymphocyte (CTL) response and tumor immunity. Upon activation by DCs, CD4+ helper T cells can cross-prime CD8+ CTLs via IL-12. However, recently activated DCs were described to prime in vitro strong T helper cell type 1 $(Th_1)$ responses, whereas at later time points, they preferentially prime $Th_2$ cells. Therfore, we examined in this study the optimum kinetic state of DCs activation impacted on in vivo priming of tumor-specific CTLs by using ovalbumin (OVA) tumor antigen model. Bone-marrow-derived DCs showed an appropriate expression of surface MHC and costimulatory molecules after 6 or 7-day differentiation. The 6-day differentiated DCs pulsed with OVA antigen for 8 h (8-h DC) and followed by restimulation with LPS for 24 h maintained high interleukin (IL)-12 production potential, accompanying the decreased level in their secretion by delayed re-exposure time to LPS. Furthermore, immunization with 8-h DC induced higher intracellular $interferon(IFN)-{\gamma}+/CD8+T$ cells and elicited more powerful cytotoxicity of splenocytes to EG7 cells, a clone of EL4 cells transfected with an OVA cDNA, than immunization with 24-h DC. In the animal study for the evaluation of therapeutic or protective antitumor immunity, immunization with 8-h DC induced an effective antitumor immunity against tumor of EG7 cells and completely protected mice from tumor formation and prolonged survival, respectively. The most commonly used and clinically applied DC-based vaccine is based on in vitro antigen loading for 24 h. However, our data indicated that antigen stimulation over 8 h decreased antitumor immunity with functional exhaustion of DCs, and that the 8-h DC would be an optimum activation state impacted on in vivo priming of tumor-specific CTLs and subsequently lead to induction of strong antitumor immunity.

• Applied Microscopy
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• v.37 no.1
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• pp.43-52
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• 2007

In order to observe the localization of excretory, purified and infected antigenic protein in the tissue of Trichinella spiralis larvae, immunogoldlabeling methodology using IgG and protein A-gold complex was implemented. T. spiralis larvae obtained from rat muscle were initially cultured in medium, and secreted excretory antigen was collected for 1 or 3 days. Purified antigenic protein was obtained from homogenized T. spiralis larvae. Rabbits were then immunized with 1 or 3 days secreted excretory protein and purified 45 kDa protein, and IgG was purified from collected serum. Serum, against infected antigen, collected from rat on 1 and 4 weeks after infection with T. spiralis larvae, and IgG was purified from collected serum. T. spiralis larvae were embedded in Lowicryl HM20 medium. Then they were finally treated with immunized IgG and protein A-gold complex (particle size; 15 nm) and observed under electron microscope. In T. spiralis larvae tissue, the tissue antigen reacted with rabbit IgC antigen Day 1 secreted excretory protein, infected antigenic protein and purified 45 kDa protein. But different distribution pattern of labeled gold particles were observed. When Day 1 secreted excretoy protein was used, gold particle labeling was observed specifically on the cuticle, basal layer, esophagus interstitial matrix (EIM) and ${\alpha}_0,\;{\alpha}_1$ granules of stichocyte of the worm. In a separate group of tissue, the antigen reacted with rabbit IgG against Day 3 secreted excretory protein. Labeled gold particles were specifically distributed on the surface layer of cuticle, EIM and ${\alpha}_0$ granules of stichocyte of the worm. In case of using infected antigenic protein, gold particle labeling was specifically distributed on the cuticle and EIM of the worm. When purifed 45 kDa protein was used gold particle labeling was specifically distributed on the cuticle, basal layer, EIM and ${\alpha}_0,\;{\alpha}_1$ granules of stichocyte of the worm. Therefore, excretory antigens appeared to originate from the cuticle and ${\alpha}_0,\;{\alpha}_1$ granules of stichocyte for the first day but the cuticle layer associated with globular proteins and ${\alpha}_0$ granules of stichocyte after 3 days and infected antigens appeared to originate from the cuticle for 1 and 4 weeks after infection. These results suggest that excretory and infection specific antigens are secreted into the cuticle, basal layer, EIM and ${\alpha}_0,\;{\alpha}_1$ granules of stichocyte and 45 kDa protein may be contained these specific antigens.

• Korean Journal of Poultry Science
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• v.28 no.3
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• pp.231-237
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• 2001

To examine the effects of feed additives on the expression of perpheral blood cell surface molecules, phagocytosis and antigen specific antibody formation, broilers were randomly assigned to $T_{1}$ , $T_{2}$ , $T_{3}$ , and $T_{4}$ groups. $T_{1}$ group was fed diet without any additives for 13 weeks, $T_{2}$ was fed diet with full fat flax, $T_{3}$ was fed diet with full fat flax containing $\alpha$-tocopherol, and $T_{4}$ was fed diet with full- fat flax containing $\alpha$-tocopherol and selenium. Since 5 weeks feeding the data were examined by flow cytometry using a panel of monoclonal antibodies. The expression of monocyte in all treated groups was significantly increased, in which the ratio of expression in $T_{3}$ group was especially evident. B cell expression of all treated groups was increased more than 2 fold. The expression of CD4+(helper T cell) cell and CD8+(cytotox$ic^pressor T cell) cell of all treated groups also was increased.ed.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.10 no.2
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• pp.166-172
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• 2007

Purpose: It has recently been reported that de novo HBV infection following liver transplantation is caused by grafts from HBcAb positive donors, and this phenomenon has been observed in one third of the liver transplant patients in our center. Therefore, we investigated the presence of HBV virus DNA in liver tissues obtained from HBcAb positive donors to determine the mechanism by which de novo HBV infection occurs. Methods: This study was conducted on 6 patients that were HBsAg negative, HBsAb positive, and HBcAb positive who were donors for liver transplantation between November 1997 and November 1998 at Asan Medical Center. We isolated DNA from a portion of liver biopsy tissues that were obtained during the operation, and then identified the surface and core region of HBV DNA using nested PCR. In addition, four children who received liver grafts from these donors were monitored to determine if they became afflicted with non-HBV related diseases while receiving prophylaxis consisting of short-term HBIG treatment and long-term treatment with an antiviral agent. Results: The surface antigen region was identified in all 6 donors and the core antigen region was observed in 4 of the 6 donors. However, no episodes of de novo HBV infection with prophylaxis were observed. Conclusion: The results of this study support the results of previous studies, which indicated that HBV infection may be the main cause of de novo HBV infection in patients that receive HBsAb positive and HBcAb positive donor grafts.

• Parasites, Hosts and Diseases
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• v.36 no.4
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• pp.269-275
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• 1998

Anti-Neospora caninum antibody was detected in anti-Toxoplasma gondii positive and negative human sera by ELISA, western blot and immunofluorescence assay (IFA). Twelve cases out of 172 (6.7％) Toxoplasma-positive sera cross-reacted with both T. gondii and N. caninum antigens, and one out of 110 Toxoplasma-negative sera reacted with N. caninum antigen by ELISA. By western blot, all 12 sera reacted with T. gondii antigens with various banding patterns but specifically at 30 kDa (SAG 1), and 22 kDa （SAG2) bands. With N. caninum antigen, the number of reactive bands was reduced, however a 43 kDa band reacted in three cases in Toxoplasma-positive sera in addition to one in Toxoplasma-negative control sera. All sera of the Toxoplasma-positive group labeled surface membrane of T. gondii, but reacted differently with N. caninum. Fluorescence was detected in surface membrane, subcellular organelles, or both in N. caninum. And one case in the Toxoplasma-negative group also reacted with N. caninum strongly in subcellular organelles. This suggested that the antibody against N. caninum may be present in human sera although the positive rate was very low in this study. The possibility of human infection with N. caninum remains to be evaluated further.