Related Experiment Video

Updated: Aug 8, 2026

Using X-ray Crystallography, Biophysics, and Functional Assays to Determine the Mechanisms Governing T-cell Receptor Recognition of Cancer Antigens
09:53

Using X-ray Crystallography, Biophysics, and Functional Assays to Determine the Mechanisms Governing T-cell Receptor Recognition of Cancer Antigens

Published on: February 6, 2017

Spatial coordination of CD8 and TCR molecules controls antigen recognition by CD8+ T-cells

Israel Pecht1, Dmitry M Gakamsky

  • 1Department of Immunology, The Weizmann Institute of Science, 76100 Rehovot, Israel. israel.pecht@weizmann.ac.il

FEBS Letters
|May 26, 2005
PubMed

Insights

Efficient T-cell activation involves CD8 cooperation with T-cell receptors (TCRs) interacting with peptide-MHC (pMHC) complexes. This interaction is enhanced when pMHC initially binds to CD8 on T-cells within membrane rafts.

Area of Science:

  • Immunology
  • Cellular Biology
  • Molecular Interactions

Background:

  • T-cell activation relies on interactions between T-cell receptors (TCRs) and peptide-MHC (pMHC) complexes.
  • The role of CD8 co-receptor in facilitating these interactions is crucial for adaptive immunity.

Purpose of the Study:

  • To review the mechanisms of TCR-pMHC interactions.
  • To elucidate the cooperative role of CD8 in T-cell activation.
  • To model the efficient association pathway between pMHC and T-cells.

Main Methods:

  • Analysis of TCR and CD8 populations using lateral diffusion rate constants.
  • Observation of distinct association phases of class I MHC tetramers ((pMHC)4) with T-cells.
  • Development of a model for pMHC-T-cell association.

Main Results:

  • Two distinct TCR/CD8 populations with different diffusion rates were identified.
  • Two association phases of (pMHC)4 with T-cells suggest a multi-step binding process.
  • Efficient pMHC-T-cell association involves fast tetramer binding to CD8/TCR populations in membrane rafts.

Conclusions:

  • Ligand-cell association initiates with pMHC binding to CD8.
  • CD8 binding promotes subsequent TCR engagement, enhancing overall association.
  • Raft-associated CD8-TCR subpopulations are key drivers of T-cell activation.

More Related Videos

Spatial and Temporal Control of T Cell Activation Using a Photoactivatable Agonist07:48

Spatial and Temporal Control of T Cell Activation Using a Photoactivatable Agonist

Published on: April 25, 2018

Use of Single Chain MHC Technology to Investigate Co-agonism in Human CD8+ T Cell Activation12:09

Use of Single Chain MHC Technology to Investigate Co-agonism in Human CD8+ T Cell Activation

Published on: February 28, 2019

Related Concept Videos

Antigens Involved in Adaptive Immunity01:26

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.
Diversity of Antigen Receptors01:28

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...
Antigen Presenting Cells01:22

Antigen Presenting Cells

The immune system is a complex network of cells and molecules that protects the body from foreign invaders. T cells, a type of white blood cell, play a crucial role in this process. They recognize and attack foreign substances, such as pathogens, that enter the body.
T cells require the help of antigen-presenting cells (APCs), which process foreign antigens into smaller fragments that can be recognized by T cells. These APCs are highly specialized cells that efficiently internalize antigens...
T Cell Activation and Clonal Selection01:22

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...
T Cell Types and Functions01:24

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...
Cytotoxic T Cells-mediated Immune Response01:27

Cytotoxic T Cells-mediated Immune Response

Cytotoxic T cells are a vital component of the immune system. They have the remarkable ability to identify and target antigens on infected or abnormal cells. These antigens often originate from intracellular pathogens such as viruses or abnormal proteins cancer cells produce.
Immunological surveillance is the ability of immune cells to monitor and eliminate infected cells with intracellular pathogens, neoplastically transformed cells, and cells with non-self antigens. Cytotoxic T cells and NK...