• 제목/요약/키워드: biology major

검색결과 2,071건 처리시간 0.031초

CD4+ cytotoxic T cells: an emerging effector arm of anti-tumor immunity

  • Seongmin Jeong;Nawon Jang;Minchae Kim;Il-Kyu Choi
    • BMB Reports
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    • 제56권3호
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    • pp.140-144
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    • 2023
  • While CD8+ cytotoxic T cells have long been considered the primary effector in controlling tumors, the involvement of CD4+ "helper" T cells in anti-tumor immunity has been underappreciated. The investigations of intra-tumoral T cells, fueled by the recent advances in genomic technologies, have led to a rethinking of the indirect role of CD4+ T cells that have traditionally been described as a "helper". Accumulating evidence from preclinical and clinical studies indicates that CD4+ T cells can acquire intrinsic cytotoxic properties and directly kill various types of tumor cells in a major histocompatibility complex class II (MHC-II)-dependent manner, as opposed to the indirect "helper" function, thus underscoring a potentially critical contribution of CD4+ cytotoxic T cells to immune responses against a wide range of tumor types. Here, we discuss the biological properties of anti-tumor CD4+ T cells with cytotoxic capability and highlight the emerging observations suggesting their more significant role in anti-tumor immunity than previously appreciated.

Review of Neospora caninum and neosporosis in animals

  • Dubey, John-P.
    • Parasites, Hosts and Diseases
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    • 제41권1호
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    • pp.1-16
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    • 2003
  • Neospora caninum is a coccidian parasite of animals. It is a major pathogen for cattle and dogs and it occasionally causes clinical infections in horses, goats, sheep, and deer. Domestic dogs are the only known definitive hosts for N. caninum. It is one of the most efficiently transmitted parasite of cattle and up to 90% of cattle in some herds are infected. Transplacental transmission is considered the major route of transmission of N. caninum in cattle. Neospora caninum is a major cause of abortion in cattle in many countries. To elicit protective immunity against abortion in cows that already harbor a latent infection is a major problem. This paper reviews information on biology, diagnosis, epidemiology and control of neosporosis in animals.

꿀벌 계통별 로얄제리 생산성 평가 및 특성 분석 (Evaluation of Royal Jelly Productivity and Characteristics in Apis mellifera Inbred Lines)

  • 김혜경;이명렬;이만영;최용수;한상미;강아랑;이경용
    • 한국양봉학회지
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    • 제32권3호
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    • pp.155-162
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    • 2017
  • 로얄제리 생산성 우수계통 선발을 위해 국내 육성서양종꿀벌 원종 계통인 A와 C에 대한 로얄제리 생산성 및 접수율 평가를 수행하였다. 그 결과 꿀벌 계통C의 로얄제리 생산량은 $33.7{\pm}7.41g$로A 계통에 비해 높은 것으로 드러났으며, 접수율 또한 $87.8{\pm}7.5%$로 A 계통에 비해 높은 것으로 확인되었다. 이들 계통으로부터 생산된 로얄제리 trans-10-hydroxy-2-decenoic acid (10-HDA) 함량을 분석한 결과 꿀벌 계통 C는 4.28%(${\pm}0.3$)으로, A 계통에 비해 높은 것으로 나타났다. 일령에 따른 major royal jelly proteins(MRJPs) 전사체 발현량을 비교한 결과 10일령의 일벌의 경우 C 계통이 A 계통에 비해 MRJP 발현량이 큰 폭으로 증가했음을 확인 할 수 있었으며, 15일령의 일벌의 MRJP 발현량 또한 C계통이 A 계통에 비해 높은 것을 확인할 수 있었다. 이러한 결과를 통해 본 연구에서는 국내 육성 서양종꿀벌 기본종 계통 중 로얄제리 생산성이 가장 우수한 계통은 C 계통인 것으로 평가 되었으며, 향후 로얄제리 생산성 우수 계통 선발을 위한 기초 자료로 제공 될 수 있을 것이라 기대하고 있다.

A Possible Significance in Vertebrate Phototransduction of Multi-Protein Signaling Complexes on Raft-Like Membranes

  • Hayashi, Fumio;Liu, Han;Seno, Keiji
    • Journal of Photoscience
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    • 제9권2호
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    • pp.47-50
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    • 2002
  • Raft is a distinctive membrane domain enriched in a certain class of lipids, cholesterol, and proteins observed on the plasma membrane. Growing evidence has revealed that such membrane domains play key roles in signal transduction, fertilization, development, transmitter release, and so on. Recently, we have isolated raft-like detergent-resistant membrane (DRM) fraction from bovine photoreceptor rod outer segments. Transducin and its effecter, cGMP-phosphodiesterase, elicited stimulus-dependent translocation between detergent-soluble membrane and DRM. This suggested potential importance of such distinct membrane domains in vertebrate phototransduction. Here, we will discuss physiological meaning of the translocation of major components of cGMP cascade to raft-like membrane in phototransduction. We would like to propose a hypothesis that raft-like membrane domains on the disk membrane are the place where cGMP cascade system could be quenched.

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Cloning and Expression of a Farnesyl Diphosphate Synthase in Centella asiatica (L.) Urban

  • Kim, Ok Tae;Ahn, Jun Cheul;Hwang, Sung Jin;Hwang, Baik
    • Molecules and Cells
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    • 제19권2호
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    • pp.294-299
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    • 2005
  • A cDNA encoding farnesyl diphosphate synthase (FPS; EC2.5.1.1/EC2.5.1.10) was isolated from Centella asiacita (L.) Urban, using degenerate primers based on two highly conserved domains. A full-length cDNA clone was subsequently isolated by rapid amplification of cDNA ends (RACE) PCR. The sequence of the CaFPS (C. asiatica farnesyl diphosphate synthase) cDNA contains an open reading frame of 1029 nucleotides encoding 343 amino acids with a molecular mass of 39.6 kDa. The deduced CaFPS amino acid sequence exhibits 84, 79, and 72%, identity to the FPSs of Artemisia annua, Arabidopsis thaliana, and Oryza sativa, respectively. Southern blot analysis suggested that the C. asiatica genome contains only one FPS gene. An artificially expressed soluble form of the CaFPS was identified by SDS-PAGE. It had high specific activity and produced farnesyl diphosphate as the major isoprenoid.

Effects of Temperature and Urea on in vitro Aggregation of Tryptophan Synthase $\alpha$-Subunits

  • Park, Myung-Won;Jeong, Jae-Kap;Shin, Hae-Ja;Lim, Woon-Ki
    • 대한의생명과학회지
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    • 제9권4호
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    • pp.203-207
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    • 2003
  • Protein aggregation could be problematic as causes of diseases and hindrance in the production of useful recombinant proteins. Aggregation of mutant tryptophan synthase $\alpha$-subunits was examined by treatment with urea and at high temperature. Large amorphous aggregate seemed to appear by heat treatment, while more various aggregates in size were formed by treatment with urea at low concentration. The result indicates that different aggregate in size could be formed depending on the treatment condition, suggesting different mechanisms underlying aggregation processes.

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Looking Inside the Cell for Mechanisms of Immunotoxicity: Experimental Design and Approaches Aimed Toward Elucidation of 2,3,7,8-Tetrachlor- dibenzo-p-dioxin-mediated B Cell Dysfunction

  • Norbert E. Kaminski;Kang, Jong-Soon
    • Toxicological Research
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    • 제17권
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    • pp.205-210
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    • 2001
  • One of the major focuses and perhaps the greatest challenges during the past decade in the discipline of immunotoxicology has been the elucidation of the molecular mechanisms responsible for immunotoxicity by specific agents. Much is currently understood about the basic underlying intracellular processes that control leukocyte effector function. This fundamental information in cell biology can now be applied toward developing systematic approaches, through the application of cell and molecular biology techniques, to identify the intracellular targets and processes disrupted by immunotoxicants. The objective of this paper is two fold. First to discuss fundamental principles of experimental design aimed at elucidation of cellular mechanisms in immunotoxicology; and second to discuss the application of molecular biology techniques in characterizing the mechanism of TCDD-induced B cell dysfunction as a working example.

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Involvement of Cytochrome P450 in (-)-(4R)-Isopiperitenone Oxidation by Cell Suspension Cultures of Mentha piperita

  • Park, Si-Hyung;Chang, Yung-Jin;Kim, Kyung-Hyun;Kim, Soo-Un
    • Journal of Microbiology and Biotechnology
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    • 제9권2호
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    • pp.147-149
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    • 1999
  • Biotransformation of exogenous (-)-(4R)-isopiperitenone in cell suspension cultures of Mentha piperita resulted in oxidized products, with (-)-7-hydroxyisopiperitenone being the major compound. The mass of products obtained $unde^{18}O_2$, atmosphere was two units higher than that under normal atmosphere. The biotransformation was inhibited by several cytochrome P450-specific inhibitors as well as by carbon monoxide. Carbon monooxide inhibition was substantially overcome by irradiation of cells with blue light including light at 450nm wavelength. These results suggested that a cytochrome P450-type monooxygenase was involved in the biotransformation.

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