• Parasites, Hosts and Diseases
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• v.46 no.4
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• pp.279-283
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• 2008

To examine humoral immune responses in the host, we measured serum antibody levels in different strains of mice (ICR, BALB/c, and C3H) experimentally infected with Neodiplostomum seoulense. Specific IgG antibody levels were increased remarkably with little difference among 3 strains of mice infected with N. seoulense from day 7 to 35 post-infection. More target proteins of adult parasites reacted with IgG at the time when the worm recovery decreased compared with other times. More than 20 protein bands, from 14 kDa to 94 kDa in size, were separated from the crude antigen of N. seoulense adults by SDS-PAGE, and among them 26, 30, 35, 43, 54, 67, and 94 kDa proteins were the major antigenic proteins. The results suggest that significant IgG antibody responses occur against N. seoulense in mice and this may be related with expulsion of worms.

• Journal of the East Asian Society of Dietary Life
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• v.9 no.2
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• pp.200-206
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• 1999

This study was carried out to get a industrial information about a possibility of IgY antibody production, antimicrobial activity and Properties of IgY antibody in egg yolk. After the initial immunization the anti-Salmonella typhimurium IgY antibody level gradually were decreased from firth week to tenth week. On the other hand, the antibody level in the serum were increased from the first week, reaching its peak in the sixth week. Molecular weights of IgY were estimated approximately 72-75KD in a heavy chain and 30-40KD in a light chain by electrophoresis.

• Parasites, Hosts and Diseases
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• v.59 no.3
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• pp.257-263
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• 2021

Human gnathostomiasis is a parasitic disease caused by Gnathostoma nematode infection. A rapid, reliable, and practical immunoassay, named dot immuno-gold filtration assay (DIGFA), was developed to supporting clinical diagnosis of gnathostomiasis. The practical tool detected anti-Gnathostoma-specific IgG4 in human serum using crude extract of third-stage larvae as antigen. The result of the test was shown by anti-human IgG4 monoclonal antibody conjugated colloidal gold. The sensitivity and specificity of the test were both 100% for detection in human sera from patients with gnathostomiasis (13/13) and from healthy negative controls (50/50), respectively. Cross-reactivity with heterogonous serum samples from patients with other helminthiases ranged from 0 (trichinosis, paragonimiasis, clonorchiasis, schistosomiasis, and cysticercosis) to 25.0% (sparganosis), with an average of 6.3% (7/112). Moreover, specific IgG4 antibodies diminished at 6 months after treatment. This study showed that DIGFA for the detection of specific IgG4 in human sera could be a promising tool for the diagnosis of gnathostomiasis and useful for evaluating therapeutic effects.

• Tuberculosis and Respiratory Diseases
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• v.42 no.4
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• pp.455-464
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• 1995

Background: Considering that both humoral and cell mediated immunities play an important role for human tuberculosis infection, enzyme-linked immunosorbent assay(ELISA) measurement of immunoglobulin G (IgG) antibody to mycobacterial antigens can be used for the serologic diagnosis of tuberculous pleural effusion. Method: We measured absorbance values of IgG antibodies to purified-protein-derivative (PPD) and lipoarabinomannan-B (LAM-B) in the pleural fluid (PF) and the serum in 40 tuberculous (TPE) and 19 nontuberculous pleural effusions (NTPE). Results: 1) The IgG antibodies to PPD and LAM-B were significantly (P<0.0005) higher in the PF and the serum of TPE compared to NTPE. 2) The IgG antibodies to PPD and LAM-B in the serum were higher than that in PF. 3) Significant correlations were found between pleural and serum IgG antibodies to PPD and LAM-B. 4) With a cutoff value for IgG antibody to PPD in the PF of 0.091, sensitivity was 55.0% and specificity 94.7% in the diagnosis of TPE. 5) With a cutoff value for IgG antibody to LAM-B in the PF of 0.337, sensitivity was 50.0% and specificity 94.7% in the diagnosis of TPE. 6) The seropositive rates in TPE were not related to PPD skin test status, the amount of PF and coexisting active pulmonary tuberculosis. Conclusion: The assay of IgG antibodies to PPD and LAM-B might be useful for the diagnosis of TPE. Our study suggests the mechanism of passive transfer of IgG antibodies to PPD and LAM-B from the serum to the PF through pleural tissue.

• BMB Reports
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• v.30 no.5
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• pp.326-331
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• 1997

To construct a competitive ELISA standard curve for the detection of glucose-6-phosphate debydrogenase (G6PD), we used highly purified native G6PD (nG6PD) as both immobilized and soluble antigens and anti-G6PD serum raised against nG6PD as antibody. The polystyrene cuvettes coated with nG6PD were challenged with a mixture of a limiting amount of anti-G6PD serum and various doses of nG6PD as competitors followed by incubation with alkaline phosphatase-anti-IgG conjugate. The competitive ELISA did not exhibit the typical sigmoidal dose-response curve characteristic of competition immunoassays under the optimal concentrations of antigen and antibody. The soluble nG6PD used as competitor failed to effectively inhibit the binding of antibodies to the immobilized nG6PD. The addition of NADP, a cofactor of G6PD enzyme, to coating buffer used for immobilizing nG6PD to the cuvettes and PBS-Tween-BSA buffer for diluting competitors did not improve the inhibition of antibody binding to immobilized nG6PD by soluble n/G6PD. The addition of BSA to coating buffer did not increase inhibition, either. Surprisingly, when partially active G6PD (paG6PD), obtained by repeated freeze-thawing, was used as competitor, the antibody binding to either immobilized nG6PD or immobilized paG6PD was inhibited 49-58%. We conclude that an effective competitive ELISA system with nG6PD enzyme and anti-G6PD serum for the detection of G6PD may not be established due to the poor inhibition of antibody binding to immobilized nG6PD by soluble nG6PD under the present assay conditions and that the inhibition may be improved by using an inactivated enzyme as competitor regardless of the type of immobilized antigen used. These results imply that the immobilized nG6PD may undergo denaturation upon binding to the polystyrene cuvettes and that our anti-G6PD serum may recognize denatured enzyme better than active enzyme.

• YAKHAK HOEJI
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• v.40 no.4
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• pp.422-427
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• 1996

The anti-Ex-A IgG was specifically labeled with stable isotopes, DL-His-2,4-$d_2$, L-Phe-$d_5$, L-Trp-$d_5$, L-Tyr-2,6-$d_2$ and L-[1-$^{13}C$]Trp, by growing hybridoma cell in serum-free medium. By use of NMR spectroscopy with selectively labeled Fab fragment, we applied a paratope mapping on antigen-antibody complex. Assignments of the observed carbonyl carbon resonances have been determined by using $^{13}C$-$^{15}N$ double labeling method in order to assign the Trp resonances. Photo CIDNP was also applied to investigate the antigen-binding site(s) on the surface residues of antibody. We found that Trp 36, which is located at the $V_H$ domain, is an important residue to bind to Ex-A, however, two Tyr on the surface of anti-Ex-A IgG plays no crucial role to bind to antigen. On the basis of these results, we demonstrate that stable isotope-aided NMR strategy can be extended to molecular structural analyses of the complex of an Fab fragment and a protein antigen.

• Parasites, Hosts and Diseases
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• v.60 no.3
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• pp.181-185
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• 2022

Strongyloides stercoralis infection is not endemic in the Republic of Korea (Korea) with a positivity rate of <1% in stool examination. However, there is a risk of hyperinfection in immunosuppressed individuals. It is necessary to determine the seropositivity of S. stercoralis antibodies in Korea. This study investigated the seropositivity of S. stercoralis antibodies in the southeastern area of Korea. From January 2019 to June 2021, serum samples were collected from participants who visited the study center in the southeastern region of Korea for routine health check-ups. We determined serum levels of specific anti-Strongyloides IgG antibodies in 834 samples by enzyme-linked immunosorbent assay. We observed that 92 samples (11.0%) tested showed a positive response. The age of the participants was 51±10.7 years, and 43.4% of them were men. The antibody positivity rate based on the location of the participants' residence were 12.3% (Gyoungsangnam-do), 10.2% (Busan), and 10.1% (Ulsan), respectively. Total eosinophil count was associated with positive test results (154.8±152.0 per mm³ versus 202.1±178.9 per mm³, P=0.006). Logistic regression analysis revealed that blood eosinophil count, age above 50 years, and residence in Sacheon were factors associated with the positive status of S. stercoralis antibody. Our finding suggests that it is necessary to test for S. stercoralis in actual clinical settings in Korea.

• Parasites, Hosts and Diseases
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• v.24 no.2
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• pp.159-170
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• 1986

A total of 69 patients of confirmed neurocysticercosis was followed serologically by ELISA up to 22 months after praziquantel treatment. The intervals and numbers of follow-up were variable by patient. Serially collected samples of serum and CSF were examined simultaneously for their specific IgG antibody levels by ELISA, using cystic fluid, saline extracts of bladder wall and scolex as antigen. Within 4 months after praziquantel treatment, the antibody levels were elevated temporarily in both serum and CSF in most patients. In some cases antibody levels exhibited steady declining tendency after the treatment. Concomitant administration of dexamethasone appeared to suppress the elevation of antibody levels. The rate of mean absorbance of antibody changed more in serum than in CSF. The rate of elevation was greater in antibodies to parenchymal antigens than that to cystic fluid, but absolute difference of antibody levels was greater in antibody to cystic fluid. Previously negative samples for IgG antibody may become positive after the praziquantel treatment, which could be used as a complementary tool (provocation test) in serodiagnosis. One month was considered to be sufficient interval for the follow-up test for that purpose. In the follow-up of up to 22 months, only few cases of chronic neurocysticercosis showed declining tendency of IgG antibody levels below negative range. During acute encephalitic attacks in chronic patients, IgG antibody to parenchymal antigen were elevated in CSF temporarily. These results indicated that serologic follow-up of every year was recommendable to differentiate the cured patients from chronic patients with slowly calcifying lesions.

• Parasites, Hosts and Diseases
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• v.54 no.5
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• pp.637-643
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• 2016

The immune correlate of host resistance induced by reinfection of Trichinella spiralis remains unclear. In this study, we investigated immune correlates between the resistance and serum IgG antibody level, $CD23^+$ $IgM^+$ B cells, and eosinophil responses induced by T. spiralis reinfection. Mice were primarily infected with 10 or 100 T. spiralis larvae (10 TS, 100 TS), respectively, and after 4 weeks, they were challenge infected with 100 T. spiralis larvae (10-100 TS, 100-100 TS). Upon challenge infections, 10-100 TS mice induced significantly higher levels of T. spiralis-specific total IgG antibody responses in sera and antibody secreting cell responses in spleens compared to 100-100 TS mice, resulting in significantly reduced worm burdens in 10-100 TS mice (60% and 70% reductions for adult and larvae, respectively). Higher levels of eosinophils were found in mice primarily infected with 10 TS compared to those of 100 TS at week 8 upon challenge. $CD23^+$ $IgM^+$ B cells were found to be increased significantly in mice primarily infected with 10 TS. These results indicate that primary infection of 10 larvae of T. spiralis, rather than 100 larvae, induces significant resistance against reinfection which closely correlated with T. spiralis-specific IgG, eosinophil, and $CD23^+$ $IgM^+$ B cell responses.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1194-1199
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• 1997

The effect of hot taste preference on selected immune responses was investigated in human peripheral immunocompetent cells. Human lymphocytes and natural killer(NK) cells were prepared at a concentration of 2$\times$$10^{6}$ cells/ml in RPMI-1640 containing 10% fetal bovine serum. Lymphocytes proliferation was determined with the [$^{3}H$]-thymidine pulse for 18hrs after concanavalin A, phytohemagglutinin, Salmonella typhimurium mitogen, or media alone. NK cell activity was measured by cytolysis of $^51Cr$-labeled target cells K562. Serum antibodies levels such as IgM, IgG, IgA were also measured by ELISA method. There was no difference of serum IgM level among the groups, but IgG and IgA levels were greater in the group with hot taste preference than those of the group without hot taste preference. In lymphocytes of the group with hot taste preference there was a greater mitogen-induced lymphocyte proliferative responses compared to the group without hot taste preference. In addition, NK cell activity in group with hot taste preference was lower than that of the group without hot taste preference. These results suggest that the eating habit of spicy food containing hot components may affect immune status by modulating selective immunocompetent cells function.