通过MHCII类细胞质域发送信号是抗原呈现所必需的,并诱导B7表达
N Nabavi1, G J Freeman, A Gault
1Department of Immunopharmacology, Roche Research Center, Nutley, New Jersey 07110.
Nature
|November 19, 1992
概括
截断的II类主要基因相容性复合体 (MHC) 分子通过影响B7分子诱导,损害B细胞抗原呈现. 恢复信号通路,就像循环AMP一样,可以扭转这种缺陷.
科学领域:
- 免疫学 免疫学 免疫学
- 分子生物学分子生物学
- 细胞信号传递 细胞信号传递
背景情况:
- 第二类主要基因相容性复合体 (MHC) 分子对于B淋巴细胞中的抗原呈现和信号转导至关重要.
- 以前的研究表明,在5C2 B淋巴瘤细胞中,工程I-Ak分子与截断的细胞质域损害了抗原呈现和信号传递.
- 循环AMP (cAMP) 类似物可以在5C2转菌剂中恢复这些功能.
研究的目的:
- 为了研究由截断的II类MHC分子损害信号传导和B细胞辅助分子B7的诱导之间的联系.
- 为了确定恢复B7表达是否可以逆转抗原呈现缺陷.
- 阐明II类细胞质域在T细胞受体参与时的信号传输中的作用.
主要方法:
- 使用B淋巴瘤细胞转菌剂 (5C2) 表达基因工程I-Ak分子与截断的细胞质域.
- 评估了抗原呈现和抗Ia诱导的细胞内信号传递.
- 研究了循环AMP类似物对恢复功能的影响.
- 研究了B细胞辅助分子B7的诱导及其逆转.
- 表面II类MHC在正常人B细胞上的交叉连接.
主要成果:
- 截断的II类MHC分子的信号传导受损导致B7分子诱导的缺陷.
- 恢复B7表达逆转了抗原呈现缺陷.
- 通过II类细胞质域的信号传输,模拟由dibutyrylcAMP,诱导B7表达.
- 表面II类MHC分子的交联诱导了B7表达在正常休息的人类B细胞上.
结论:
- 通过II类MHC细胞质域传输信号对于诱导B7表达至关重要.
- 这种诱导的B7表达对于B细胞有效呈现抗原至关重要.
- 这些发现突出了一个新的机制,将MHC信号与B淋巴细胞中的共刺激分子表达联系起来.
相关概念视频
Cell-mediated Immune Responses
Overview
Antigens Involved in Adaptive Immunity
An antigen is any substance the immune system identifies as foreign and potentially harmful to the body, prompting an immune response. Antigens have two functional properties: immunogenicity and reactivity. Immunogenicity is the ability of an antigen to stimulate a specific immune response. At the same time, reactivity describes the antigen's ability to react with the cells and antibodies produced in response to it.
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
Complete Antigens
Complete antigens possess both immunogenicity and reactivity.
Antigen Processing Pathways
MHC molecules are key players in the immune response, enabling T cells to recognize and respond to specific antigens. They are present on the surface of all nucleated cells in the body and are instrumental in presenting antigens to T cells and activating them. T cells recognize the MHC-antigen complex and initiate an immune response. MHC class I and MHC class II are two main types of MHC molecules, each associated with a distinct antigen processing pathway.
MHC Class I: Presenting Endogenous...
MHC Class I: Presenting Endogenous...
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...
T Cell Types and Functions
When T cells with CD4 markers are activated, they give rise to two types of effector cells: helper T cells and regulatory T cells. Meanwhile, T cells with CD8 markers differentiate into effector cytotoxic T cells. The differentiation of CD4 T cells into helper T cell subsets, such as Th1, Th2, and Th17 cells, is dependent on the antigen type, antigen-presenting cell, and regulatory cytokines.
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
Th1 cells stimulate dendritic cells to express necessary co-stimulatory molecules on their surfaces for...
B 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...


