• YAKHAK HOEJI
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• v.39 no.3
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• pp.260-267
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• 1995

A lectin from the edible mushroom, Lentinus edodes, was purified through physiological saline extraction, ammonium sulfate fractionation and column chromatographies. On polyacrylamide gel electrophoresis, 0.05M fraction from hydroxyapatite column exhibited adjacent four sharp bands. The partially purified lectin agglutinated the erythrocytes of rabbit, mouse and rat, but not agglutinated human erythrocytes. The lectin's mitogenic effects were tested by its application to human and murine splenic lymphocytes. The results showed that the 0.05M fraction from hydroxyapatite was mitogenic, and the optimal dose of Lentinus edodes lectin was slightly lower than Con A by the culture with murine splenic and human peripheral lymphocytes. Meanwhile, its ability to agglutinate transformed cells was tested by its administration to continuous cell lines L1210 and HeLa cells. The leetin was found to be an agglutinin of tumor cell lines tested by L1210 and HeLa cells.

• YAKHAK HOEJI
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• v.41 no.4
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• pp.421-432
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• 1997

A new lectin was partially purified from starfish,Asterina pectinifera by means of physiological saline extraction, salt fractionation, ion exchange chromatography and hy droxyapatite chromatography, and it was named APL. The biochemical properties of the APL were characterized. In addition, its effects on lymphocyte mitogenicity and cancer cell agglutinability were tested. The APL agglutinated nonspecifically human erythrocytes and rabbit blood cells. Agglutinability was decreased to 30% of control activity below pH 5 and above pH 9 and was relatively unstable at increasing temperatures above 60$^{\circ}C$. The activity was reduced by addition of two kinds of metal ions, $Ba^{2+},\;Mn^{2+}$ and chelating agent, EDTA. APL was proved to be glycoproteins containing 9% sugars. For carbohydrate specificity, it was found that the activity of APL was inhibited by D(+)-glucosamine, D(+)-galactosamine, stachyose, N-acetyl-galactosamine and methyl-${\alpha}$-D-galactopyranoside among 35 sugars tested. In amino acid composition, the contents of acidic amino acids such as aspartic acid and glutamic acid were relatively high. This result suggest that the isoelectric point would be in a lower range. APL was found that it promotes the division of human lymphocytes. APL was proved to be a potent agglutinin for cancer cells such as HeLa, L929 and L1210 cells. Significant changes on the HeLa cell surfaces affected by APL were observed under the electron microscope.

• The Journal of the Korean Society for Microbiology
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• v.21 no.1
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• pp.151-161
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• 1986

In order to develop sensitive and sepcific assay methods for E. coli heat labile enterotoxin(LT) hybridoma cell lines secreting LT specific monoclonal antibody were obtained. LT was purified from cell lysate of E. coli O15H11. The steps included disruption of bacteria by French pressure, DEAE Sephacel ion exchange chromatography, Sephadex G200 gel filtration, and second DEAE Sephacel ion exchange chromatography, successively. Spleen cells from Balb/c mice immunized with the purified LT and $HGPRT^{(-)}$ plasmacytomas, $P3{\times}63Ag8.V653$ were mixed and fused by 50% (w/v) PEG. Hybrid cells were grown in 308 wells out of 360 wells, and 13 wells out of them secreted antibodies reacting to LT. Among these hybridoma cell 1G8-1D1 cell line was selected since it had produced high-titered monoclonal antibody continuously. By using culture supernatant and ascites from 1G8-1D1 cells the monoclonal antibody was characterized, and an assay system for detecting enterotoxigenic E. coli was established by double sandwich enzyme-linked immunosorbent assay (ELISA). The following results were obtained. 1. Antibody titers of culture supernatant and ascites from 1G8-1D1 hybridoma cells were 512, and 102, 400, respectively by GM1-ELISA and its immunoglobulin class was IgM. 2. The maximum absorption ratio of 1G8-1D1 cell culture supernatant to LT was 90% at $300\;{\mu}g/ml$ of LT concentration. LT concentration shown at 50% absorption ratio was $103.45{\mu}g$ and the absorption ratio was decreased with tile reduction of LT concentration. This result suggests that monoclonal antibody from 1G8-1D1 hybridoma cell bound with LT specifically. 3. The reactivities of 1G8-1D1 cell culture supernatant to LT and V. cholerae enterotoxin(CT) were 0.886 and 0.142(O.D. at 492nm) measured by the GM1-ELISA, indicating 1G8-1D1 monoclonal antibody reacted specifically with LT but not with CT. 4. The addition of 0.1ml of ascites to 0.6mg and 0.12mg of LT decreased the vascular permeability factor to 41% and 44% respectively, but it did not completely neutralize LT. 5. By double sandwich ELISA using monoclonal antibody, as little as 75ng of the purified LT per ml could be detected. 6. The results by assay of detecting LT in culture supernatants of 14 wild strains E. coli isolated from diarrhea patients by the double sandwich ELISA were almost the same level as those by reverse passive latex agglutination.

• The Journal of the Korean Society for Microbiology
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• v.21 no.4
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• pp.447-453
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• 1986

To diagnose the typhoid fever rapidly and accurately in clinically suspected patients, the levels of IgG subclass antibody were measured by enzyme-linked immunosorbent assay(ELISA). With symptom, blood culture and agglutination test, tested persons were categorized into 6 groups as typhoid fever, FUO, paratyphi A or B, other bacterial infctions, cancers, and control. ELISA was performed on the polyvinyl chloride plates coated with killed whole cell($10^8\;cell/ml$) of S. typhi 0901W by poly-L-lysine applied as binding substance (and polyvinyl chloride as solid phase). The distribution of the level of IgG subclass antibodies in each group was analyzed and compared with other groups. The results obtained were summarized as follow: 1. The optimal dilution of the sera from patients with typhoid fever was 1:160, and those of the sheep anti-human IgG subclass and the peroxidase conjugated rabbit anti-sheep IgG were 1:4000 and 1:5000, respectively. 2. The absorbance levels of IgG subclass in the sera of typhoid fever patients were as follows; a) IgG1 value is $0.439{\pm}0.110$ b) IgG2 value is $0.416{\pm}0.165$ c) IgG3 value is $0.449{\pm}0.145$ d) IgG4 value is $0.525{\pm}0.154$ IgG subclass levels in the sera of typhoid patients were much higher than in control group and patient with paratyphi A or B as well as other infectious diseases. The sensitivity and the specificity in differential diagnosis of typhoid fever and other febrile diseases were 92% and 79% in the assay of IgG1 respectively, whereas those in the assay of IgG2 were 97% and 72%, respectively (above absorbance 0.3). 3. The absorbance levels of IgG subclass in the serial sera of typhiod fever patients tend to decrease to the level of absorbance 0.3 in 10 months from the onset of illness. 4. The order of absorbance levels of IgG subclass in the serum of each group were typhoid fever, paratyphi A or B, other infectious diseases, control and cancer. 5. For the serodiagnosis of typhoid fever against other febrile diseases, the sensitivity and the specificity in the assay of IgG2 activity were 76% and 93% in absorbance 0.4, respectively. 6. In the distribution of the level of each IgG subclass in the sera of FUO patients which were suspected of typhoid fever, the positive rate was ranged from 36% to 82%. This suggest that more than 50% of FUO patients are caused by S. typhi.