• 제목/요약/키워드: Antigens

검색결과 921건 처리시간 0.023초

Blockade of STAT3 in T Cells Inhibits Germinal Center Reactions against Intranasal Allergens

  • Choi, Garam;Chung, Yeonseok
    • Biomolecules & Therapeutics
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    • 제24권3호
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    • pp.244-251
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    • 2016
  • Understanding the developmental mechanisms of humoral immunity against intranasal antigens is essential for the development of therapeutic approaches against air-borne pathogens as well as allergen-induced pulmonary inflammation. Follicular helper T (Tfh) cells expressing CXCR5 are required for humoral immunity by providing IL-21 and ICOS costimulation to activated B cells. However, the regulation of Tfh cell responses against intranasal antigens remains unclear. Here, we found that the generation of Tfh cells and germinal center B cells in the bronchial lymph node against intranasal proteinase antigens was independent of $TGF-{\beta}$. In contrast, administration of STAT3 inhibitor STA-21 suppressed the generation of Tfh cells and germinal center B cells. Compared with wild-type OT-II T cells, STAT3-deficient OT-II T cells transferred into recipients lacking T cells not only showed significantly reduced frequency Tfh cells, but also induced diminished IgG as well as IgE specific for the intranasal antigens. Cotransfer study of wild-type OT-II and STAT3-deficient OT-II T cells revealed that the latter failed to differentiate into Tfh cells. These findings demonstrate that T cell-intrinsic STAT3 is required for the generation of Tfh cells to intranasal antigens and that targeting STAT3 might be an effective approach to ameliorate antibody-mediated pathology in the lung.

The Role of Dendritic Cells in Central Tolerance

  • Oh, Jaehak;Shin, Jeoung-Sook
    • IMMUNE NETWORK
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    • 제15권3호
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    • pp.111-120
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    • 2015
  • Dendritic cells (DCs) play a significant role in establishing self-tolerance through their ability to present self-antigens to developing T cells in the thymus. DCs are predominantly localized in the medullary region of thymus and present a broad range of self-antigens, which include tissue-restricted antigens expressed and transferred from medullary thymic epithelial cells, circulating antigens directly captured by thymic DCs through coticomedullary junction blood vessels, and peripheral tissue antigens captured and transported by peripheral tissue DCs homing to the thymus. When antigen-presenting DCs make a high affinity interaction with antigen-specific thymocytes, this interaction drives the interacting thymocytes to death, a process often referred to as negative selection, which fundamentally blocks the self-reactive thymocytes from differentiating into mature T cells. Alternatively, the interacting thymocytes differentiate into the regulatory T (Treg) cells, a distinct T cell subset with potent immune suppressive activities. The specific mechanisms by which thymic DCs differentiate Treg cells have been proposed by several laboratories. Here, we review the literatures that elucidate the contribution of thymic DCs to negative selection and Treg cell differentiation, and discusses its potential mechanisms and future directions.

불활화 Aujeszky’s disease virus 항원의 자돈과 실험동물에서의 면역반응 (Immune Responses in Swine and Experimental Animals Given Inactivated Aujeszky’s Disease Virus Antigens)

  • 박정우;이종인;최윤식
    • 한국동물위생학회지
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    • 제13권1호
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    • pp.54-63
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    • 1990
  • We have studied about the safety, immunity and protective potency in swine and experimental am mais of two inactivated vaccine produced with NYJ-1-87 strain of ADV that was isolated in Korea. Result obtained through the experiments were summarized as follows. 1. The safe potency of ADV antigens inactivated with BEI and formaline to mouse & guinea pig was on the whole good, but protective potency rates of those to challenge with ADV were 60-75% without the differences to two antigens. 2. Safety, immunity & protective potency of ADV antigens inactivated with BEI and formaline to swine were on the whole excellent, except for a mild increase of rectal temperature in some pigs after challenge with ADV. 3. When virus excretion of the experimental groups after challenge with ADV was examed by swabbing of nasal, all pigs of control gorup excreted virus from 2 days p.c., partially to 10 days p.c.. But in vaccinated groups, only 25-50% of all pigs of each group excreted virus during experimental periods. 4. Titers of antibodies in swine & quinea pig vaccinated with inactivated ADV antigens become increased after the 1 weeth p.i. showing the highest liters on the 4-5 weeths p.i.

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Expression of Cancer-Testis Antigens in Stem Cells: Is it a Potential Drawback or an Advantage in Cancer Immunotherapy

  • Ghafouri-Fard, Soudeh
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권7호
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    • pp.3079-3081
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    • 2015
  • Cancer-testis antigens (CTAs) are a group of tumor associated antigens with a restricted expression pattern in normal gametogenic tissues but expression in a broad range of malignancies. Their expression pattern has made them potential targets for immunotherapy. However, expression of some of these antigens has been demonstrated in normal stem cells as well as cancer stem cells (CSCs). As CSCs have been shown to be sources of metastasis and tumor recurrence, novel therapies are being focused on their eradication. On the other hand, CTA expression in normal stem cells raises the possibility that CTA based immunotherapies cause side effects in normal tissues.

Expression of Cancer-Testis Antigens in Pediatric Cancers

  • Ghafouri-Fard, Soudeh
    • Asian Pacific Journal of Cancer Prevention
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    • 제16권13호
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    • pp.5149-5152
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    • 2015
  • Cancer-testis antigens (CTAs) are a group of tumor-associated antigens with more than 140 members whose expression has been shown to be limited to gametogenic tissues and placenta among normal tissues. However, malignant tissues of different origins have shown aberrant and elevated expression of these antigens. Such a pattern of expression endows beneficial properties for use as cancer biomarkers as well as immunotherapeutic targets as a result of the immune-privileged status of the testes. CTAs have been shown to be expressed in pediatric brain tumors, different types of sarcomas, leukemias, and lymphomas as well as neuroblastomas. Although data regarding their expression pattern in childhood tumors are not as comprehensive as for adult tumors, it is supposed that CTA-based immunotherapeutic approaches can also be used for pediatric cancers. However, there are limited data about the objective clinical responses following immunotherapy in such patients. Here we try to review the available information.

Independent regulation of antigen processing and presentation on induction of antibody responses to various bacterial antigens in C3H/He mice

  • Kim, Hyung-Su;Jeong, Gajin
    • Journal of Microbiology
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    • 제33권4호
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    • pp.355-362
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    • 1995
  • Induction of antibody production in C3H/He mice by bacterial infection is regulated through the processing exerted by antigen presenting cells. From the studies with Psudomonas aeruginosa, Salmonella typhimurium, and Micrococcus luteu, lipopolysaccharides (LPS) in Gram negative bacteria, which are known to be T-cell independent B cell mitogen, seem to be the major factor stimulating immune responses via activation of macrophages. Activation of macrophage, however, does not seem to correlate with antibody production. M. luteus was easily eliminatd by activated macrophages, while the processed antigens were immediately releasedd into culture medium before presentation. Nevertheless, antigens from Gram positive bacteria, Staphylococcus aureus and Bacillus subtilis, were very very active in chemotaxis and activation of periotoneal macrophages as well as in antien presnetation, while the very nature of the antigens is not yet clearly understood.

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An Intrusion Detection Method Based on Changes of Antibody Concentration in Immune Response

  • Zhang, Ruirui;Xiao, Xin
    • Journal of Information Processing Systems
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    • 제15권1호
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    • pp.137-150
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    • 2019
  • Although the research of immune-based anomaly detection technology has made some progress, there are still some defects which have not been solved, such as the loophole problem which leads to low detection rate and high false alarm rate, the exponential relationship between training cost of mature detectors and size of self-antigens. This paper proposed an intrusion detection method based on changes of antibody concentration in immune response to improve and solve existing problems of immune based anomaly detection technology. The method introduces blood relative and blood family to classify antibodies and antigens and simulate correlations between antibodies and antigens. Then, the method establishes dynamic evolution models of antigens and antibodies in intrusion detection. In addition, the method determines concentration changes of antibodies in the immune system drawing the experience of cloud model, and divides the risk levels to guide immune responses. Experimental results show that the method has better detection performance and adaptability than traditional methods.

Evaluation of Recombinant SAG1, SAG2, and SAG3 Antigens for Serodiagnosis of Toxoplasmosis

  • Khanaliha, Khadijeh;Motazedian, Mohammad Hossein;Kazemi, Bahram;Shahriari, Bahador;Bandehpour, Mojgan;Sharifniya, Zarin
    • Parasites, Hosts and Diseases
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    • 제52권2호
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    • pp.137-142
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    • 2014
  • Serologic tests are widely accepted for diagnosing Toxoplasma gondii but purification and standardization of antigen needs to be improved. Recently, surface tachyzoite and bradyzoite antigens have become more attractive for this purpose. In this study, diagnostic usefulness of 3 recombinant antigens (SAG1, SAG2, and SAG3) were evaluated, and their efficacy was compared with the available commercial ELISA. The recombinant plasmids were transformed to JM109 strain of Escherichia coli, and the recombinants were expressed and purified. Recombinant SAG1, SAG2, and SAG3 antigens were evaluated using different groups of sera in an ELISA system, and the results were compared to those of a commercial IgG and IgM ELISA kit. The sensitivity and specificity of recombinant surface antigens for detection of anti-Toxoplasma IgG in comparison with commercially available ELISA were as follows: SAG1 (93.6% and 92.9%), SAG2 (100.0% and 89.4%), and SAG3 (95.4% and 91.2%), respectively. A high degree of agreement (96.9%) was observed between recombinant SAG2 and commercial ELISA in terms of detecting IgG anti-Toxoplasma antibodies. P22 had the best performance in detecting anti-Toxoplasma IgM in comparison with the other 2 recombinant antigens. Recombinant SAG1, SAG2, and SAG3 could all be used for diagnosis of IgG-specific antibodies against T. gondii.

돼지 위축성 비염, 파스튜렐라성 폐렴 및 흉막폐렴 원인균의 주요 항원에 대한 IgG 와 IgY 의 상관 관계 분석 (Relationship of Antibodies in Egg Yolk and Serum against Major Antigens of Bacterial Agents in Porcine Atrophic Rhinitis, Pneumonic Pasteurellosis and Pleuropneumonia)

  • 신나리;김종만;유한상
    • 대한수의학회지
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    • 제42권3호
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    • pp.371-376
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    • 2002
  • Swine respiratory diseases have induced severe economic lasses in swine industry worldwide. Therefore, several methods have been made and applied to prevent and control the diseases. However, these methods still have a problem and also induce side effects. Recently, the use of egg yolk antibody was introduced to control and prevent the diseases as one of new trials. As a study of using egg yolk antibody, antibody titers against several different antigens of major pathogens in swine respiratory diseases were compared in egg yolk and serum of hens immunized with those antigens. The titers were measured by ELISA using the antigens as coating antigens. The relationship in antibody titers between egg yolk and serum were identified by analysis of variance for linear regression. Almost of antigens used in this study showed the high relationship in antibody titers between egg yolk and serum (r = 0.87 ~ 0.93) even though the relationship in antibody titers against P. multocida A:3 IROMP was slightly low (r = 0.74)(P<0.01). These results indicated that antibody titer in egg yolk could be useful to predict the titer in serum of chicken.

Clinical Significance of Co-expression of Aberrant Antigens in Acute Leukemia: A Retrospective Cohort Study in Makah Al Mukaramah, Saudi Arabia

  • Abdulateef, Nahla Ahmad Bahgat;Ismail, Manar Mohammad;Aljedani, Hanadi
    • Asian Pacific Journal of Cancer Prevention
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    • 제15권1호
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    • pp.221-227
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    • 2014
  • Background: Aberrant phenotypes in acute leukemia have variable frequency and their prognostic and predictive relevance is controversial, despite several reports of clinical significance. Aims: To determine the prevalence of aberrant antigen expression in acute leukemia, assess clinical relevance and demonstrate immunophenotype-karyotype correlations. Materials and Methods: A total of 73 (40 AML and 33 ALL) newly diagnosed acute leukemia cases presenting to KAMC, Kingdom of Saudi Arabia, were included. Diagnosis was based on WHO criteria and FAB classification. Immunophenotyping by flow cytometry, conventional karyotyping and fluorescence in situ hybridization for gene rearrangements were performed. Results: Aberrant antigens were detected in 27/40 (67.5%) of AML and in 14/33 (42.4%) in ALL cases. There were statistically significant higher TLC in Ly+ AML than in Ly-AML (p=0.05) and significant higher blast count in ALL with aberrant antigens at presentation and day 14 (p=0.005, 0.046). There was no significant relation to clinical response, relapse free survival (RFS) or overall survival (p>0.05), but AML cases expressing ${\geq}2$ Ly antigens showed a lower median RFS than those expressing a single Ly antigen. In AML, CD 56 was expressed in 11/40. CD7 was expressed in 7/40, having a significant relation with an unfavorable cytogenetic pattern (p=0.046). CD4 was expressed in 5/40. CD19 was detected in 4/40 AML associated with M2 and t (8; 21). In ALL cases, CD33 was expressed in 7/33 and CD13 in 5/33. Regarding T Ag in B-ALL CD2 was expressed in 2 cases and CD56 in 3 cases. Conclusions: Aberrant antigen expression may be associated with adverse clinical data at presentation. AML cases expressing ${\geq}2$ Ly antigens may have shorter median RFS. No specific cytogenetic pattern is associated with aberrant antigen expression but individual antigens may be related to particular cytogenetic patterns. Immunophenotype-karyotype correlations need larger studies for confirmation.