HIV感染は,その受容体であるCD4の内細胞化を必要としません
P J Maddon1, J S McDougal, P R Clapham
1Department of Biochemistry and Molecular Biophysics, College of Physicians and Surgeons, Columbia University, New York, New York 10032.
Cell
|September 9, 1988
まとめ
ヒト免疫不全ウイルス (HIV) は,CD4分子が内部化できるが,内細胞症ではなく,直接融合によって細胞に侵入する. この研究では,CD4変異体を使用してHIVの侵入メカニズムを調査しました.
科学分野:
- 免疫学 免疫学とは
- ウイルス学 ウイルス学 ウイルス学
- 細胞生物学 細胞生物学
背景:
- CD4分子はT細胞機能に不可欠であり,ヒト免疫不全ウイルス (HIV) の受容体として機能する.
- CD4+T細胞は,ホルボールのエステルまたは抗原を提示する細胞によって刺激されると,CD4分子を内部化することができます.
- HIVが細胞に侵入するメカニズムは,エンドサイトーシスによるものであれ,直接的な融合によるものであれ,依然として研究の対象となっている.
研究 の 目的:
- HIVがCD4+T細胞に侵入するメカニズムを解明する.
- HIVの侵入が受容体媒介性エンドサイトーシスまたは細胞膜との直接的なウイルス融合によって起こるかどうかを判断する.
- HIV感染におけるCD4分子内細胞症の役割を調査する.
主な方法:
- 細胞プラズマ領域内細胞症の障害のある2つのCD4タンパク質変異体の構築.
- ワイルド型または変異性CD4を発現するHeLa細胞系を用いた定量感染性研究.
- HIV結合およびその後のCD4内細胞化の評価.
主要な成果:
- ワイルド型または変異性CD4を発現するHeLa細胞系は,HIV感染に対する同等の感受性を示した.
- CD4+T細胞にHIVが結合するとCD4内分細胞症は発生しなかった.
- エンドサイトーシスに障害がある変異性CD4分子は,HIV感染性を変化させなかった.
結論:
- HIVの細胞への侵入は,ウイルス包膜と細胞膜の直接融合によって起こります.
- CD4分子の内部化はHIVの侵入の前提条件ではない.
- CD4分子のHIVとの相互作用は,ウイルスの侵入のために受容体媒介性エンドサイトーシスを必要としません.
関連する概念動画
Receptor-mediated Endocytosis
105.5K
Overview
105.5K
Retrovirus Life Cycles
43.1K
Retroviruses have a single-stranded RNA genome that undergoes a special form of replication. Once the retrovirus has entered the host cell, an enzyme called reverse transcriptase synthesizes double-stranded DNA from the retroviral RNA genome. This DNA copy of the genome is then integrated into the host’s genome inside the nucleus via an enzyme called integrase. Consequently, the retroviral genome is transcribed into RNA whenever the host’s genome is transcribed, allowing the...
43.1K
Retroviruses
12.2K
Retroviruses and retrotransposons both insert copies of their genetic elements into the genome of the host cell. Thus, the viral genes are passed on when the host genome is replicated or translated. A typical retroviral DNA sequence contains 3-4 genes that encode the different proteins required for its structural assembly and function as a molecular parasite. This DNA is transcribed into a single mRNA, which is very similar in structure to conventional mRNAs, i.e., it is capped at the 5’...
12.2K
Receptor-mediated Endocytosis
10.3K
Receptor-mediated endocytosis is when bulk amounts of specific molecules are imported into a cell after binding to cell surface receptors. The molecules bound to these receptors are taken into the cell through inward folding of the cell surface membrane, which is eventually pinched off into a vesicle within the cell. Structural proteins, such as clathrin, coat the budding vesicle.
Clathrin-Mediated Endocytosis of LDL
One well-characterized example of receptor-mediated endocytosis is the...
Clathrin-Mediated Endocytosis of LDL
One well-characterized example of receptor-mediated endocytosis is the...
10.3K
Immune Response Against Viral Pathogens
2.4K
The immune system's response to viral infections is a complex and coordinated process involving natural killer (NK) cells, T cell-mediated responses, and antibody-mediated responses.
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
NK Cells
NK cells are a crucial part of our innate immune system, acting as the first line of defense against viral infections. These cells can recognize and kill infected cells without prior exposure to the virus, effectively slowing down the spread of infection. Additionally, NK cells produce proinflammatory...
2.4K
Size and Structure of Viral Genomes
1.2K
Viral genomes exhibit remarkable diversity in size, structure, and composition, influencing their replication strategies and interactions with host cells. These genomes consist of either DNA or RNA and may be linear or circular. Additionally, they can be single-stranded or double-stranded, with each configuration affecting how the virus propagates within a host. RNA viruses, for instance, generally have smaller genomes than DNA viruses, a factor that contributes to their high mutation rates and...
1.2K


