関連する実験動画
Updated: Jun 20, 2026
14:29
Examination of Thymic Positive and Negative Selection by Flow Cytometry
Published on: October 8, 2012
自己反応性Bリンパ球の除去は,発育停止と細胞死という2段階で行われます
S B Hartley1, M P Cooke, D A Fulcher
1Howard Hughes Medical Institute, Stanford University School of Medicine, California 94305.
Cell
|February 12, 1993
まとめ
自己反応性B細胞は,骨髄における発達停止とその後の細胞死によって除去されます. 発育停止を伴うこの新しい経路は,自己免疫を予防するために不可欠です.
科学分野:
- 免疫学 免疫学とは
- 細胞生物学 細胞生物学
- 発達生物学 発達生物学とは
背景:
- 自己反応性Bリンパ球は,自己免疫疾患を予防するために,発達中に除去されなければならない.
- B細胞の耐性メカニズムに関する現在の理解は不完全である.
研究 の 目的:
- 自己抗原に遭遇したトランス遺伝子マウスにおけるB細胞除去のメカニズムを解明する.
- B細胞の耐性における発達停止と細胞死亡の役割を調査する.
主な方法:
- 自己抗原を発現するトランスジェニックマウスモデルを使用した.
- 分析されたB細胞の発達,粘着分子の発現,骨髄におけるアポトーシス.
- bcl-2トランスゲンの発現がB細胞の除去に与える影響を調査した.
主要な成果:
- 未成熟のB細胞における抗原との遭遇は,発達停止を誘発し,重要な分子獲得を阻害する.
- この発達停止は,抗原を除去すると逆転する.
- 拘束されたB細胞は,1~3日以内にアポトーシスを起こします.
- bcl-2トランスゲン発現は遅延するが,細胞死を防ぐことはできず,自己反応性B細胞の脱出を可能にします.
結論:
- B細胞の除去には2段階のプロセスが含まれます: 発達停止に続いて細胞死.
- 発達停止は,抗原に依存する重要なチェックポイントです.
- この経路の脆弱性は,自己免疫疾患の病原性における潜在的な障害点を強調しています.
関連する概念動画
01:17The Extrinsic Apoptotic Pathway
The extrinsic apoptotic pathway is initiated when extracellular death-inducing signals, such as specific cytokines, activate the death receptors expressed on the cell surface. The immune cells involved in this pathway are natural killer cells (NK cells) and cytotoxic T-lymphocytes. NK cells are critical in innate immune response, while cytotoxic T-lymphocytes are associated with adaptive immune response. These cells recognize specific receptors expressed on the altered cells and activate...
01:31The Intrinsic Apoptotic Pathway
Internal cellular stress, such as cellular injury or hypoxia, triggers intrinsic apoptosis. The B-cell lymphoma 2 (Bcl-2) family of proteins are the primary regulators of the intrinsic apoptotic pathway. For example, during DNA damage, checkpoint proteins, such as Ataxia Telangiectasia Mutated (ATM protein) and Checkpoints Factor-2 (Chk2) proteins, are activated. These proteins phosphorylate p53 which further activates pro-apoptotic proteins, such as Bax, Bak, PUMA, and Noxa, and inhibits...
01:20Special Features of Adaptive Immunity
The adaptive immune system, a crucial component of the overall immune response, offers a highly specialized defense against pathogens. It involves specific cell types and features, enabling it to combat infections effectively and efficiently.
The primary cell types involved in adaptive immunity are T cells and B cells. Each type has a unique role in defending the body against pathogens. T cells are responsible for cell-mediated immunity. They identify and eliminate infected cells directly,...
The primary cell types involved in adaptive immunity are T cells and B cells. Each type has a unique role in defending the body against pathogens. T cells are responsible for cell-mediated immunity. They identify and eliminate infected cells directly,...
01:23Cells of the Adaptive Immune Response
The T and B lymphocytes of the adaptive immune system develop from common lymphoid progenitor cells in the bone marrow. These progenitors give rise to precursors that eventually develop into both T and B lymphocytes. As these precursors mature, they gain the ability to detect and respond to foreign antigens in the body, a process known as immunocompetence. Additionally, these precursors acquire self-tolerance, a process that ensures they do not react to self-antigens. This intricate system...
01:24B Cell Activation and Differentiation
The adaptive immune response, a sophisticated defense mechanism, relies on the activation and differentiation of B lymphocytes, or B cells. These processes enable our bodies to mount a tailored response against specific pathogens such as bacteria, free virus particles, toxins, and parasites.
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
When naive B cells encounter a specific antigen that can bind to the B cell receptor (BCR) on their surface, they undergo sensitization to respond to the antigen's presence. Sensitization begins with...
01:22Cellular Injury V: Apoptosis and Autophagy
Cells respond to damage and stress through highly coordinated processes that decide whether they survive or undergo controlled self-destruction. Two major pathways involved in this regulation are apoptosis, a type of programmed cell death, and autophagy, a survival mechanism that helps cells adapt to adverse conditions.ApoptosisApoptosis removes aged or injured cells to maintain tissue balance. During this process, the cell shrinks, chromatin condenses and fragments, and membrane-bound...