• Parasites, Hosts and Diseases
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• 제57권2호
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• pp.93-99
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• 2019

Both Plasmodium spp. and Toxoplasma gondii are important apicomplexan parasites, which infect humans worldwide. Genetic analyses have revealed that 33% of amino acid sequences of inner membrane complex from the malaria parasite Plasmodium berghei is similar to that of Toxoplasma gondii. Inner membrane complex is known to be involved in cell invasion and replication. In this study, we investigated the resistance against T. gondii (ME49) infection induced by previously infected P. berghei (ANKA) in mice. Levels of T. gondii-specific IgG, IgG1, IgG2a, and IgG2b antibody responses, $CD4^+$ and $CD8^+$ T cell populations were found higher in the mice infected with P. berghei (ANKA) and challenged with T. gondii (ME49) compared to that in control mice infected with T. gondii alone (ME49). P. berghei (ANKA) + T. gondii (ME49) group showed significantly reduced the number and size of T. gondii (ME49) cysts in the brains of mice, resulting in lower body weight loss compared to ME49 control group. These results indicate that previous exposure to P. berghei (ANKA) induce resistance to subsequent T. gondii (ME49) infection.

• Journal of Microbiology and Biotechnology
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• 제34권7호
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• pp.1419-1424
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• 2024

Secretin PilQ is an antigenically conserved outer membrane protein that is present in most meningococci and PorA is a major protein that elicits bactericidal immune response in humans following natural disease and immunization. In the present study, BALB/c mice were immunized subcutaneously with rPilQ406-770 or rPorA together with Freund's adjuvant (FA). Serum antibody responses to serogroup A and B Neisseria meningitides whole cells or purified proteins and functional activity of antibodies were determined by ELISA and serum bactericidal assay (SBA), respectively. Serum IgG responses were significantly increased in the immunized group with rPilQ406-770 or rPorA together with FA compared to control groups. IgG antibody response of mice immunized with rPilQ406-770 was significantly more than mice immunized with rPorA (OD at 450 nm was 1.6 versus 0.83). The booster injections were effective in increasing the responses of antirPilQ406-770 or anti-rPorA IgG significantly. Antisera produced against rPilQ406-770 or rPorA demonstrated strong surface reactivity to serogroup B N. meningitides in comparison with control groups. Antisera raised against rPorA or rPilQ406-770 and FA demonstrated SBA titers from 1/1024 to 1/2048 against serogroup B. The strongest bactericidal activity was detected in sera from mice immunized with rPilQ406-770 mixed with FA. These results suggest that rPilQ406-770 is a potential vaccine candidate for serogroup B N. meningitidis.

• Biomolecules & Therapeutics
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• 제7권2호
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• pp.127-132
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• 1999

Triazine herbicide has been reported to directly suppress the immune response. In the present study, the effect of simazine on the immune response was investigated. Splenic lymphocytes were treated withmitogen (lipopolysaccaride, concanavalin A) in the presence of simazine. When simazine(300 mg/kg, 600 mg/kg) was administrated every day for 3 weeks or 4 weeks, respectively, the number of plaque forming cells (PFC) was decreased. Antibody production of IgM and IgG class was significantly decreased in splenic cells from simazine-treated animals. In addition, when animals were exposed to simazine, the susceptibility of virus infection as well as the growth of tumor cells was increased. These data suggest that simazine affected the immune function and humoral immunity impaired by simazine treatment contributed to pathological process.

• 대한수의학회지
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• 제31권4호
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• pp.441-447
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• 1991

In this study, effect of levamisole, selenium and tocopherol on the lymphocyte blastogenesis and antibody production in Korean native goat were evaluated in vitro and in vivo. Lymphocyte blastogenesis of goat blood increased significantly (p<0.01 and p<0.05) when the cells were treated in vitro with levamisole at the concentration of $50{\sim}500{\mu}g/ml$, with selenium at the concentration of $0.062{\sim}1.0{\mu}g$ and with tocopherol nt the concentration on $12.5{\mu}g$. Increased lymphocyte blastogenesis was detected from 2 to 24 hours after oral administration of levamisole (2.5mg/kg of body weight). After 7 days, increased mitogenic response of lymphocytes was not detected. Meanwhile increased blastogenesis of lymphocyte from goats given the selenium-tocopherol mixture (selenium $100{\mu}g$-tocopherol 200IU/head/day) was detected from 10 days after feeding, and the tendency continued throughout the entire experimental period. When immune responses of goats against PPD were subjected to test by ELISA, the mean IgG titers of levamisolc group (1 : 1,800) and selenium-tocopherol group (1 : 960) were higher than that of control group (1 : 600) at 2 weeks after lst inoculation. At 3 weeks after lst inoculation and 1 week after 2nd inoculation, the significant (p<0.05) differences in IgG titers were detected among the three groups. The mean IgG titers of levamisole group, selenium-tocopherol group and control at that time were 1 : 20,480, 1 : 5,120 and 1 : 2,640, respectively. The IgG production of levamisole group was significantly (p<0.01) higher than that of control group.

• Parasites, Hosts and Diseases
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• 제48권1호
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• pp.23-33
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• 2010

An understanding of the nature of the immune response to asexual erythrocytic stages of malaria parasites will facilitate vaccine development by identifying which responses the vaccine should preferentially induce. The present study examined and compared the immune responses of NIH mice in either single or mixed infections with avirulent (DK) or virulent (DS) strains of Plasmodium chabaudi adami using the ELISA test for detecting and measurement of cytokines and antibody production. In both single and mixed infections, the study showed that both cell- and antibody-mediated responses were activated. In all experiments, an early relatively high level of IFN-$\gamma$ and IgG2a during the acute phase of the infection, and later elevation of IL-4 and IgG1, suggested that there was a sequential Th1/Th2 response. However, in the avirulent DK strain infection a stronger Th1 response was observed compared to the virulent DS strain-infection or in mixed infections. In the virulent DS infection, there was a stronger Th2 response compared to that in the DK and mixed infections. The faster proliferation rate of the virulent DS strain compared to the DK strain was also evident.

• 한국어병학회지
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• 제27권2호
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• pp.99-105
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• 2014

Biosensors consist of biochemical recognition agents like antibodies immobilized on the surfaces of transducers that change the recognition into a measurable electronic signal. Here we report a piezoelectric immunosensor made to detect Vibrio vulnificus. A 9MHz AT-cut piezoelectric wafer attached with two gold electrodes of 5mm diameter was used as the transducer of the QCM biosensor with a reproducibility of ${\pm}0.1Hz$ in frequency response. We have tried different approaches to immobilize antibody on the sensor chip. Concerning the orientation of antibody for the best antigen binding capacity, the antibody was immobilized by specific binding to protein G or by cross-linking through hydrazine. In addition, protein G was cross-linked on glutaraldehyde activated immine layer (PEI) or EDC/NHS activated sulfide monolayer (MPA). PEI was found to be more effective to immobilize protein G following glutaraldehyde activation than MPA. However, hydrazine chip showed a better capability to immobilize more IgG than protein G chip and a higher sensitivity. The sensor system was able to detect V. vulnificus in dose dependent manner and was able to detect bacterial cells within 5 minutes by monitoring frequency shifts in real time. The detection limit can be improved by preincubation to enrich the bacterial cell number.

• Clinical and Experimental Pediatrics
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• 제56권7호
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• pp.286-290
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• 2013

Purpose: Although chronic and recurrent rhinosinusitis is prevalent in children, little is known about its causes. Here, we investigated the humoral immunity in children with chronic or recurrent rhinosinusitis. Methods: We examined 16 children attending the outpatient clinic at the CHA Bundang Medical Center including 11 boys and 5 girls, aged 3-11 years (mean age, 5.6 years), who had rhinosinusitis for >3 months or >3 times per year. The complete blood count with differential and total serum concentrations of Immunoglobulin (Ig) E, IgA, IgD, IgM, IgG, and IgG subclasses ($IgG_1$, $IgG_2$, $IgG_3$, and $IgG_4$) of all children were measured. All subjects received 23-polysaccharide pneumococcal vaccination (PPV), and the levels of antibodies to 5 serologic types (4, 6B, 14, 18C, and 23F) of pneumococcal capsular polysaccharide antigens were measured before and after vaccination. Post-PPV antibody titers ${\geq}0.35{\mu}g/mL$ or with a ${\geq}4$-fold increase were considered as positive responses. Results: The titers of IgG, IgA, IgD, and IgM were within normal range in all 16 children, whereas the total IgE concentration was higher than normal in 2 children. $IgG_1$ deficiency was observed in 1 patient and $IgG_3$ deficiency in 3. After PPV, 1 patient failed to respond to all 5 serologic types, 2 failed to respond to 4 serologic types, and 2 failed to respond to 3 serologic types. Conclusion: Clinicians should consider the evaluation of humoral immune functions in children with chronic or recurrent rhinosinusitis who do not respond to prolonged antibiotic treatment.

• Parasites, Hosts and Diseases
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• 제60권3호
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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.

• Clinical and Experimental Vaccine Research
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• 제13권3호
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• pp.232-241
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• 2024

Purpose: Brucellosis, a zoonotic infectious disease, is a worldwide health issue affecting animals and humans. No effective human vaccine and the complications caused by the use of animal vaccines are among the factors that have prevented the eradication of the disease worldwide. However, bio-engineering technologies have paved the way for designing new targeted and highly efficacious vaccines. In this regard, the study aimed to evaluate immunity induced by mannosylated niosome containing Brucella recombinant trigger factor/Bp26/Omp31 (rTBO) chimeric protein in a mouse model. Materials and Methods: rTBO as chimeric antigen (Ag) was expressed in Escherichia coli BL21 (DE3) and, after purification, loaded on niosome and mannosylated niosome. The characteristics of the nanoparticles were assessed. The mice were immunized using rTBO, niosome, and mannosylated niosome-rTBO in intranasal and intraperitoneal routes. Serum antibodies (immunoglobulin [Ig]A, IgG, IgG1, and IgG2a) and splenocyte cytokines (interferon-gamma, interleukin [IL]-4, and IL-12) were evaluated in immunized mice. Finally, immunized mice were challenged by B. melitensis and B. abortus. A high antibody level was produced by niosomal antigen (Nio-Ag) and mannosylated noisomal antigen (Nio-Man-Ag) compared to the control after 10, 24, and 38 days of immunization. The IgG2a/IgG1 titer ratio for Nio-Man-Ag was 1.2 and 1.1 in intraperitoneal and intranasal methods and lower than one in free Ag and Nio-Ag. Cytokine production was significantly higher in the immunized animal with Ag-loaded nanoparticles than in the negative control group (p<0.05). Moreover, cytokine and antibody levels were significantly higher in the injection than in the inhalation method (p<0.05). Results: The combination of mannosylated noisome and rTBO chimeric proteins stimulate the cellular and humoral immune response and produce cytokines, playing a role in developing the protective acquired immune response in the Brucella infectious model. Also, the intraperitoneal route resulted in a successful enhancement of cytokines production more than intranasal administration. Conclusion: Designing an effective vaccine candidate against Brucella that selectively induces cellular and humoral immune response can be done by selecting a suitable nanoniosome formulation as an immunoadjuvant and recombinant protein as an immune response-stimulating Ag.

• Parasites, Hosts and Diseases
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• 제46권3호
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• pp.195-198
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• 2008

Plasmodium falciparum liver stage antigen-1 (PfLSA-1) is one of the few antigens expressed exclusively in liver stage parasites. In this study, we evaluated the antibody responses against recombinant PfLSA-1 in naturally infected individuals in Myanmar. High levels of antibody responses (70.7%) were detected in 82 serum samples from 116 infected individuals, and IgG responses to PfLSA-1 principally composed of responses of IgG1 and IgG3 subclasses. These results show that PfLSA-1 elicits effective antibody responses in individuals infected with P. falciparum, and thus it could be not only an attractive candidate protein for vaccine development, but also a useful antigen for serodiagnosis of the infection.