• Title/Summary/Keyword: T antigen

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Perturbation of host responses by Porphyromonas gingivalis biofilm (Porphyromonas gingivalis 바이오필름에 의한 숙주 면역반응의 교란)

  • Jeon, Woo-Seok;Kim, Sung-Jo;Choi, Jeom-Il
    • Journal of Periodontal and Implant Science
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    • v.32 no.4
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    • pp.827-836
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    • 2002
  • The present study was performed to evaluate how cellular and humoral immune responses were perturbed by immunization of mixed periodontal bacterial biofilms. Each group of mice was immunizared with 1) Poqhyromonas gingivalis (P. gingivaliis) grown as a planktonic culture, 2) Fusobacterium nucleatum (F. nucleatum), 3) P. gingivalis grown as a biofilm, or 4) mixed P. gingivalis plus F. nucleatum grown as a biofilm culture, respectively. Immune mouse sera were collected from each mouse. Spleens were harvested to isolate T cells and consequently stimulated with antigen presenting cells and P. gingivalis whole cell antigen to establish P. gingivalis-specific T cell lines. There were no significant differences in the mean anti- gingivalis IgG antibody titers among mouse groups. Immunization of mice with pure P. gingivalis biofilm or mixed P gingivalis plus F. nucleatum biofilm resulted in significant reduction o f antibody avidity and opsonophagocytois function. INF-$\gamma$production by P. gingivalis-specific T cell lines was also substantially recluced in mouse groups immunized with the biofilm. It was concluded that P. gingivalis biofilm perturbs the cellular and humoral immune responses in periodontal disease.

Production of monoclonal antibody to 45 kDa somatic protein of Trichuris suis (돼지편층의 45kDa 항원단백질에 대한 단클론항체 생산)

  • Lee, Jong-Kyung;Kim, Jung-Tae;Seo, Hun-Su;Park, Jong-Yeol;Yun, Hee-Jeong
    • Korean Journal of Veterinary Research
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    • v.44 no.4
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    • pp.625-635
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    • 2004
  • Trichnuris suis does not excrete eggs during larval stage as well as in particular adult stage, It is impossible to diagnose by use of fecal examination method in those periods. Therefore, serological diagnostic method can be very useful for those stages. In order to produce monoclonal antibody, specific somatic and secretory-excretory (SE) antigens of T. suis were identified and analyzed by SDS-PAGE and Western blot. Monoclonal antibody-producing hybridoma cells were cloned, which were made of popliteal lymph node of BALB/c mice immunized with a 45 kDa somatic antigen of T. suis. Five clones (1B9, 2C4, n2C5, 2D7 and 2D8) showing strong responses to T. suis antigens were selected and the isotype identified. All monoclonal antibodies were IgG1 isotype and the light chains were k chain. Established monoclonal antibodies reacted specifically to somatic and SE antigens of T. suis and did not cross-reacted to antigens of ascaris suum, trichuris vulpis, or Trichinella spiralis. The sensitivity of somatic and SE antigens against these monoclonal antibodies were significant (p<0.01) associated with those of positive and negative sera.

Cross-reactivity between sera from dogs experimentally infected with Dirofilaria immitis and crude extract of Toxocara canis

  • Song, Kun-Ho;Hayasaki, Mineo;Cho, Kyu-Woan;Lee, Sang-Eun;Kim, Duck-Hwan
    • Parasites, Hosts and Diseases
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    • v.40 no.4
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    • pp.195-198
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    • 2002
  • This study was performed to investigate whethere there is cross-reactivity between Dirofilaria immitis and three intestinal nematodes of dogs. In ELISA, D. immitis- infected dog sera obtained at the 4th molting stage (9-11 weeks) and microfilaremic stage (25-30 weeks) were shown to be highly reactive with crude extract of T. canis. In immunoblotting, some antigenic fractions, 44, 57 88, 100 kDa of crude extract of T. canis, were found to be positive reaction with sera of dogs infected with D. immitis. However, little or no cross-reaction were observed between sera of D. immitis-infected dogs and crude extract antigen of T. vulpis or A. caninum. These result suggest that there are partial cross reaction between sera of D. immitis-infected dogs and the antigen of T. canis.

The Roles of Immune Regulatory Factors FoxP3, PD-1, and CTLA-4 in Chronic Viral Infection (만성 바이러스 감염에서 면역조절인자 FoxP3, PD-1 및 CTLA-4의 역할)

  • Cho, Hyosun
    • Korean Journal of Microbiology
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    • v.49 no.3
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    • pp.221-227
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    • 2013
  • Human immunodeficiency virus (HIV), hepatitis B virus (HBV), and hepatitis C virus (HCV) cause viral infections that lead to chronic diseases. When they invade human body, virus specific T cells play an important role in antiviral effector functions including killing virus-infected cells and helping B cells to produce specific antibodies against viral proteins. The antiviral activity of T cells is usually affected by immune-regulatory factors that express on surface of T cells. Recently, many researchers have investigated the relationship between effector functions of virus specific T cells and characteristics of immune regulatory factors (e.g., CD28, CD25, CD45RO, FoxP3, PD-1, CTLA-4). In particular, Immune inhibitory molecules such as forkhead box P3 (FoxP3), programmed death-1 (PD-1), and cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) are associated with T-cell dysfunction. They are shown to be up-regulated in chronic viral diseases such as hepatitis B, hepatitis C or human immunodeficiency virus infection. Therefore, the positive correlation between viral persistence and expression of immune regulatory factors (FoxP3, PD-1, and CTLA-4) has been suggested. In this review, the roles of immune regulatory factors FoxP3, PD-1, and CTLA-4 were discussed in chronic viral diseases such as HIV, HBV, or HCV.

Use of enzyme-linked immunosorbent assay (ELISA) for detection of toxoplasmosis in dogs (ELISA 법을 이용한 개 톡소플라즈마병의 조기진단에 관한 연구)

  • Suh, Myung-deuk;Joo, Hoo-don;Lee, Byung-hoon
    • Korean Journal of Veterinary Research
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    • v.31 no.4
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    • pp.491-500
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    • 1991
  • This study was conducted to detect the serum antibodies in the experimentally toxoplasma infected dogs and street dogs by use the of an enzyme-linked immunosorbent assay (ELISA). And this test was performed on the polystylene microplate by coating with the tachyzoites soluble antigen of T gondii (RH strain), incubated with sera diluted then, added with HPO-conjugated rabbit anti-dog IgG and o-phenylenediamine used as a substrate. Tachyzoites of T gondii harvested from mouse peritoneal cavity were purified by 30, 40 and 50% Percoll density gradient centrifugation and used as the source of antigen. The results obtained were summarized as follows; 1. The highest ratio of positive to negative (P/N ratio) was obtained at the level of $l{\mu}g/ml$ protein concentration of antigen with the 1/4000 dilution of the conjugate measured by checker-board titration. It was regarded as the optimum concentration of the antigen and conjugate. 2. Cut-off value in this IgG ELISA was 0.375 that was determined by mean absorbance (at 492nm) of IFA negative serum added with the dauble value of the standard deviation $(mean{\pm}2S.D.)$. 3. Serum ELISA IgG antibodies to T gondii in the exyerimentally infected dogs were detected firstly at the Week 3 after inoculation and the highest titer was recognized at the Week 4, 5 and 6 after inoculation. 4. Stability of the antigen absorbed in the microplates that were preserved at $4^{\circ}C$ and $-25^{\circ}C$ separately were prolonged up to 3 weeks and 10 weeks at $4^{\circ}C$ and $-25^{\circ}C$, respectively. However the reproducibility was not reliable after the preservation of 4 weeks and longer. 5. Positive rate of the specific antibodies in 312 test sera was 28.5% and there was no significant differences between the male (27.8%) and female (29.5%), respectively. 6. The IgG ELISA was proved to be a specific procedure for the detection of antibodies to canine toxoplasma infection and also evaluated as a screening test for the large scale of test samples in laboratory.

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Heat-Shock Protein 70 as a Tumor Antigen for in vitro Dendritic Cell Pulsing in Renal Cell Carcinoma Cases

  • Meng, Fan-Dong;Sui, Cheng-Guang;Tian, Xin;Li, Yan;Yang, Chun-Ming;Ma, Ping;Liu, Yun-Peng;Jiang, You-Hong
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.20
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    • pp.8947-8950
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    • 2014
  • Immunological functions of heat shock proteins (HSPs) have long been recognized. In this study we aimed to efficiently purify HSP70 from renal cell carcinoma and test it as a tumor antigen for pulsing dendritic cells in vitro. HSP70 was purified from renal cell carcinoma specimens by serial column chromatography on Con A-sepharose, PD-10, ADP-agarose and DEAE-cellulose, and finally subjected to fast protein liquid chromatography (FPLC). Dendritic cells derived from the adherent fraction of peripheral blood mononuclear cells were cultured in the presence of IL-4 and GM-CSF and exposed to tumor HSP70. After 24 hours, dendritic cells were phenotypically characterized by flow cytometry. T cells obtained from the non-adherent fraction of peripheral blood mononuclear cells were then co-cultured with HSP70-pulsed dendritic cells and after 3 days T cell cytotoxicity towards primary cultured renal cell carcinoma cells was examined by Cell Counting Kit-8 assay. Dendritic cells pulsed in vitro with tumor-derived HSP70 expressed higher levels of CD83, CD80, CD86 and HLA-DR maturation markers than those pulsed with tumor cell lysate and comparable to that of dendritic cells pulsed with tumor cell lysate plus TNF-${\alpha}$. Concomitantly, cytotoxic T-lymphocytes induced by HSP70-pulsed dendritic cells presented the highest cytotoxic activity. There were no significant differences when using homologous or autologous HSP70 as the tumor antigen. HSP70 can be efficiently purified by chromatography and induces in vitro dendritic cell maturation in the absence of TNF-${\alpha}$. Conspecific HSP70 may effectively be used as a tumor antigen to pulse dendritic cells in vitro.

The Interaction between HCV-Infected huh7.5 Cells and HCV-Specific T Cells (C형 간염 바이러스 감염 간암 세포주와 T 림프구의 상호작용에 대한 연구)

  • Kang, Hyojeung;Cho, Hyosun
    • Korean Journal of Microbiology
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    • v.50 no.2
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    • pp.169-172
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    • 2014
  • Recently, Hepatitis C virus (HCV) replication system has been established using human hepatoma cells (huh cell) and a variety of HCV clones. In this study, we established an infectious HCV replication system using huh7.5 cells and J6/JFH1 clone (genotype 2a). In addition, we investigated the antigen presentation capability of HCV-infected huh7.5 cells to HCV-specific T cells. Interestingly, HCV-infected huh7.5 cells were not capable of activating HCV-specific T cells. However, huh7.5 cells stimulated by exogenous HCV peptide were able to activate HCV-specific T cells, which was shown to produce TNF-${\alpha}$ and IFN-${\gamma}$. We further examined if HCV infection has an inhibitory effect on the expression of MHC class I molecule of huh7.5 cells. We found that HCV infection did not change the expression level of MHC class I molecule on huh7.5 cells.

Synergistic Anti-Tumor Effect by the Combination of Cyclophosphamide and Dendritic Cell Vaccination in Murine Tumor Model that CEA Expressing (CEA 발현 마우스 종양모델에서 Cyclophosphamide와 수지상세포 백신의 병합치료에 의한 상승적인 항종양 효과)

  • Park, Mi-Young
    • Korean Journal of Clinical Laboratory Science
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    • v.54 no.1
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    • pp.38-48
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    • 2022
  • Carcinoembryonic antigen (CEA) is an oncofetal antigen primarily detected in the peripheral blood of cancer patients, particularly in those with colorectal cancer. CEA is considered a valuable target for antigen-specific immunotherapy. In this study, we induced the anti-tumor immunity for CEA through the administration of a dendritic cell (DC) vaccine. However, there was a limitation in inducing tumor regression in the DC vaccinated mice. To enhance the efficacy of anti-tumor immunity in MC38/CEA2 tumor-bearing mice, we evaluated the effects of DC vaccine in combination with cyclophosphamide (CYP). Administration of CYP 100 mg/kg in mice resulted in significant inhibition of tumor growth in the 2-day tumor model, whereas a lower inhibition of tumor growth was seen in the 10-day tumor model. Therefore, the 10-day tumor model was selected for testing chemo-immunotherapy. The combined CYP and DC vaccine not only increased tumor antigen-specific immune responses but also induced synergistic anti-tumor immunity. Furthermore, the adverse effects of CYP such as weight loss and immunosuppression by regulatory T cells and myeloid-derived suppressor cells showed a significant reduction in the combined chemo-immunotherapy treatment compared with CYP alone. Our data suggest that chemoimmunotherapy with the DC vaccine may offer a new therapeutic strategy to induce a potent anti-tumor effect and reduce the adverse effects of chemotherapy.