结合MHCII类分子的内源性表位的多样性受到不变链限制
概括
不变链 (Ii) 调节主要基因相容性复合体 (MHC) II类表现,有时阻断,有时需要表位. 这会影响抗原呈现,可能与自身免疫有关.
科学领域:
- 免疫学 免疫学 免疫学
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- 不变链 (Ii) 在它们的合成过程中与主要基因相容性复合体 (MHC) II 类分子结合.
- Ii 防止在内细胞网膜中过早结合,并将MHC II 类引导到内体区.
- 了解II的作用对于区分抗原呈现途径和自身免疫性疾病机制至关重要.
研究的目的:
- 为了调查不变链 (Ii) 在主要基因相容性复合体 (MHC) II类抗原呈现中的精确作用.
- 确定II是否仅仅阻断或促进特定内源性表位的表现.
- 评估表达II的小鼠在缺少II时暴露的表位细胞的免疫性耐受性.
主要方法:
- 使用了淘汰和转基因小鼠模型的组合.
- 使用T细胞杂交瘤的综合面板探测了脏细胞.
- 在II的存在和缺席下分析了内源合成表位的呈现.
主要成果:
- 不变链 (ii) 显示出复杂的调节作用,阻断了一些内源性表位的呈现.
- 相反,发现某些表位需要II才能有效呈现.
- 表达II的小鼠对II缺席时被揭露的表位体没有耐受性.
结论:
- 不变链 (Ii) 对MHCII类抗原呈现的影响并不直接,涉及抑制和促进功能.
- 这些发现表明,Ii在抗原处理中的作用比以前假设的更为细微.
- 在小鼠中对依赖II的表位体缺乏耐受性对理解自身免疫性疾病的发病有重大影响.
相关概念视频
Ligand Binding and Linkage
Allosteric proteins have more than one ligand binding site; the binding of a ligand to any of these sites influences the binding of ligands to the other sites. When a protein is allosteric, its binding sites are called coupled or linked. In the case of enzymes, the site that binds to the substrate is known as the active site and the other site is known as the regulatory site. When a ligand binds to the regulatory site, this leads to conformational changes in the protein that can influence the...
Protein Complexes with Interchangeable Parts
Groups of proteins may form a complex where each protein in this complex has a different role in the overall execution of the complex’s function. Often some of the proteins in the complex can be replaced by a closely related variant to give a complex that contains many of the same components yet is functionally distinct.
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
The SCF ubiquitin ligase is a protein complex of five individual proteins. This complex attaches ubiquitin to other target proteins to mark them for degradation. In order to...
Mismatch Repair
Organisms are capable of detecting and fixing nucleotide mismatches that occur during DNA replication. This sophisticated process requires identifying the new strand and replacing the erroneous bases with correct nucleotides. Mismatch repair is coordinated by many proteins in both prokaryotes and eukaryotes.
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
The Mutator Protein Family Plays a Key Role in DNA Mismatch Repair
The human genome has more than 3 billion base pairs of DNA per cell. Prior to cell division, that vast amount of genetic...
Immunoglobulin-like Cell Adhesion Molecules
Immunoglobulin-like cell adhesion molecules or Ig-CAMs are a versatile group of cell surface glycoproteins belonging to the immunoglobulin protein superfamily. Ig-CAMs possess the characteristic immunoglobulin protein domains and other domains such as the fibronectin type III domain. The Ig domains are glycosylated to varying degrees in different Ig-CAMs.
Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs...
Ig-CAMs exhibit either homophilic binding (to other Ig-CAMs) or heterophilic binding (to other ligands such as integrins). While most Ig-CAMs...
Diversity of Antigen Receptors
Antigen receptors are essential components of the immune system crucial in defending the body against foreign invaders. These receptors are present on the surface of B and T cells, enabling them to recognize antigens and mount an appropriate immune response.
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
Before encountering any antigen, lymphocytes express these receptors. On B cells, the antigen receptor is a membrane-bound antibody molecule called BCR; on T cells, it is a T cell receptor or TCR. B and T cell receptors are composed of two...
T Cell Activation and Clonal Selection
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...


