胎児および成人における血液形成の際にアルファ4インテグリンに対する異なる要求事項
A G Arroyo1, J T Yang, H Rayburn
1Howard Hughes Medical Institute, Cambridge, Massachusetts 02139, USA.
Cell
|June 28, 1996
まとめ
アルファ4インテグリンは,出生後のT細胞産生と骨髄におけるB細胞発育に不可欠です. これらの受容体は,T細胞のペイヤー指向に不可欠です.
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 発達生物学について
背景:
- インテグリンは,細胞-細胞および細胞-細胞外マトリックス相互作用に関与する重要な細胞表面受容体です.
- アルファ4インテグリン (CD49d/CD29およびCD49d/CD104) はリンパ球と単細胞の結合と移動を媒介する.
研究 の 目的:
- リンパ性および骨髄性細胞の発達と密輸におけるアルファ4インテグリンの特定の役割を調査する.
- 血液形成におけるアルファ4インテグリンに対する発達段階特有の要件を決定する.
- 二次リンパ性臓器へのT細胞本位化のアルファ4インテグリンの機能を明らかにする.
主な方法:
- 異なるレベルのアルファ4インテグリンを発現するキメリックマウスを利用した.
- 血液形成細胞の発達と骨髄の分化を分析した.
- in vivoモデルを使用して,様々なリンパ性組織へのT細胞の密輸を評価しました.
主要な成果:
- T細胞の発達は胎児期のアルファ4インテグリン独立ですが,出生後に依存するようになります.
- T細胞とB細胞のための骨髄前駆体であるアルファ4インテグリンは,正常な発達のために必要である.
- モノサイトと自然キラー細胞は,α4インテグリンなしで正常に発達する.
- アルファ4インテグリンは,T細胞がペイヤー・パッチへ向くのに不可欠であるが,,リンパ節,または一般的な腸内皮質には向かない.
結論:
- アルファ4インテグリンは,リンパ球特異的で,骨髄血液形成における発達的に調節された役割を果たします.
- これらのインテグリンは,産後T細胞の産生とB細胞の発達に不可欠です.
- アルファ4インテグリンは,ペイヤーパッチに特化したT細胞の指向を媒介し,組織特有の粘着機能を強調します.
関連する概念動画
Regulation of Angiogenesis and Blood Supply
Rapidly dividing tumors, embryos, and wounded tissues require more oxygen than usual, lowering the oxygen concentration in the blood. At low oxygen or hypoxic conditions, an oxygen-sensitive transcription factor called the hypoxia-inducible factor 1 or HIF1 is activated. HIF1 is a dimeric protein of alpha (ɑ) and beta (β) subunits. Under optimal oxygen conditions, HIF1β is present in the nucleus while HIF1ɑ remains in the cytosol. HIF1ɑ is hydroxylated by prolyl hydroxylase and factor...
Hematopoiesis
The process of blood cell formation is called hematopoiesis. Hematopoiesis starts early during development, on the seventh day of embryogenesis. This phase of hematopoiesis is called the primitive wave, wherein the extraembryonic yolk sac allows the production of erythroid cells and endothelial cells from a common precursor called hemangioblast. The erythroid cells provide oxygen to support the growth of the rapidly dividing embryo. Hemangioblasts later develop into hematopoietic stem cells or...
Intracellular Signaling Affects Focal Adhesions
Integrins act both as extracellular input receivers and as intracellular processing activators. As their name suggests, integrins are entirely integrated into the membrane structure. Their hydrophobic membrane-spanning regions interact with the phospholipid bilayer's hydrophobic region. These membrane receptors provide extracellular attachment sites for effectors like hormones and growth factors. They activate intracellular response cascades when their effectors are bound and active.
Some...
Some...
Overview of Hematopoiesis
Hematopoiesis, or blood cell production, is a vital biological process that begins early in embryonic development and continues throughout life. This process generates the various types of cells found in blood, including red blood cells, white blood cells, and platelets from hematopoietic stem cells (HSCs).
Developmental Phases of Hematopoiesis
Initially, HSCs are formed in the embryonic yolk sac, a critical site for early blood cell production. These stem cells subsequently migrate to other...
Developmental Phases of Hematopoiesis
Initially, HSCs are formed in the embryonic yolk sac, a critical site for early blood cell production. These stem cells subsequently migrate to other...
Role of Hematopoietic Growth Factors
Hematopoietic growth factors are molecules that regulate the differentiation rate of hematopoietic stem cells (HSCs). Erythropoietin (EPO), primarily produced by the kidneys, plays a crucial role in erythrocyte production. When oxygen levels in the blood are low, EPO is released into the bloodstream, reaching the bone marrow, where it stimulates HSCs to differentiate and mature into erythrocytes, which are vital for oxygen transport.
Thrombopoietin (TPO), mainly released by the liver,...
Thrombopoietin (TPO), mainly released by the liver,...
Development of Blood Vessels
The development of the vascular system in a fetus is a complex and intricate process that begins as early as 15 to 16 days post-conception. This process starts outside the embryo, specifically in the mesoderm of the yolk sac, chorion, and connecting stalk. Approximately two days later, the formation of blood vessels occurs within the embryo itself.
The initial formation of this system is facilitated by the small amount of yolk present in the ovum and yolk sac. Blood vessels originate from...
The initial formation of this system is facilitated by the small amount of yolk present in the ovum and yolk sac. Blood vessels originate from...


