関連する実験動画
Updated: Apr 19, 2026

14:29
Examination of Thymic Positive and Negative Selection by Flow Cytometry
Published on: October 8, 2012
22.9K
Ras/MAPKシグナリングの区画化によって定義されるチムス選択値.
Mark A Daniels1, Emma Teixeiro, Jason Gill
1Laboratory of Transplantation Immunology and Nephrology, Department of Research, University Hospital-Basel, Hebelstrasse 20, 4031 Basel, Switzerland.
Nature
|November 7, 2006
まとめ
科学者は,T細胞発達の過程で自己と非自己を区別するために重要な特定のリンガンドを特定しました. T細胞受容体の afinity のわずかな増加は,負の選択を誘発し,自己免疫を防止し,中央の許容性を確立します.
科学分野:
- 免疫学 免疫学とは
- 細胞生物学 細胞生物学
- 分子生物学は分子生物学である.
背景:
- 免疫的耐性を維持することは,自己免疫疾患の予防に不可欠です.
- 胸腺におけるT細胞の発達には,自己反応性細胞を排除するための陽性と陰性の選択が含まれます.
- これらの選択プロセスを支配する正確なメカニズムを理解することは極めて重要です.
研究 の 目的:
- T細胞発達のポジティブ・セレクションとネガティブ・セレクションの間の値を定義するリガンドを特定する.
- ティモサイトがT細胞オントゲネシス中に細胞運命を決定する方法を明らかにする.
主な方法:
- T細胞選択に影響を与える特定のリガンドの特定.
- T細胞受容体 (TCR) アフィニティの分析.
- Rasとミトゲン活性化タンパク質キナーゼ (MAPK) 信号伝達経路の調査.
- 信号介質のサブセルラー局所化の評価.
主要な成果:
- 選択値で,リガンド親和性の狭いギャップが特定されました.
- リガンド親和度のわずかな増加は,T細胞活性化とRas/MAPKシグナル伝達を著しく変化させた.
- 信号分子の差異的分割が観察されました.
- これは,ネガティブ・セレクションの誘導につながる.
結論:
- 胸腺はデジタルスイッチメカニズムを使用して,アナログの親近性信号を異なる細胞運命を決定する結果 (ポジティブとネガティブの選択) に変換します.
- 信号分子の微分区分化が,このプロセスの鍵となる.
- このメカニズムは,中央の耐性を確立し,自己免疫を予防するために不可欠です.
関連する概念動画
The Ras Gene
7.6K
The Ras-gene-encoded proteins are regulators of signaling pathways controlling cell proliferation, differentiation, or cell survival. The Ras-gene family in humans constitutes three primary members—the HRas, NRas, and KRas. These genes code for four functionally distinct yet closely related proteins—the HRas, NRas, KRas4A, and KRas4B. The involvement of mutant Ras genes in human cancer was first discovered in 1982 and is among the most common causes of human tumorigenesis.
Ras is a...
Ras is a...
7.6K
mTOR Signaling and Cancer Progression
5.1K
The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The mTOR pathway or the...
5.1K
Interactions Between Signaling Pathways
8.0K
Signaling cascades usually lack linearity. Multiple pathways interact and regulate one another, allowing cells to integrate and respond to diverse environmental stimuli.
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
Convergence and divergence, and cross-talk between signaling pathways
Two distinct signaling pathways can converge on a single functional unit, which may either be a single protein or a complex of proteins. The response is either functionally distinct or synergistic between the two pathways but different from the response...
8.0K
MAPK Signaling Cascades
9.5K
Mitogen-activated protein kinase, or MAPK pathway, activates three sequential kinases to regulate cellular responses such as proliferation, differentiation, survival, and apoptosis. The canonical MAPK pathway starts with a mitogen or growth factor binding to an RTK. The activated RTKs stimulate Ras, which recruits Raf or MAP3 Kinase (MAPKKK), the first kinase of the MAPK signaling cascade. Raf further phosphorylates and activates MEK or MAP2 Kinases (MAPKK), which in turn phosphorylates MAP...
9.5K
PI3K/mTOR/AKT Signaling Pathway
6.5K
The mammalian target of rapamycin (mTOR) is a serine/threonine kinase that regulates growth, proliferation, and cell survival in response to hormones, growth factors, or nutrient availability. This kinase exists in two structurally and functionally distinct forms: mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). The first form (mTORC1) is composed of a rapamycin-sensitive Raptor and proline-rich Akt substrate, PRAS40. In contrast, mTORC2 consists of a...
6.5K
T Cell Activation and Clonal Selection
17.9K
T cells are integral to our adaptive immune system, recognizing and effectively responding to foreign antigens. T cell activation and clonal selection are pivotal in orchestrating this immune response. This article elucidates these mechanisms, detailing the roles of cluster of differentiation (CD) markers, major histocompatibility complex (MHC) molecules, costimulatory signals, and the process of clonal selection.
Naive T cells that have not yet encountered an antigen express two primary CD...
Naive T cells that have not yet encountered an antigen express two primary CD...
17.9K

