Related Experiment Video

Updated: Aug 4, 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

Comparison of the roles of CD8 alpha alpha and CD8 alpha beta in interaction with MHC class I

J Sun1, P B Kavathas

  • 1Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT 06520, USA.

Journal of Immunology (Baltimore, Md. : 1950)
|April 29, 1998
PubMed

Insights

The CD8beta chain does not enhance cell adhesion to MHC class I. Instead, CD8beta may be involved in promoting CD8/TCR interactions and signaling pathways in T cells.

Area of Science:

  • Immunology
  • Molecular Biology
  • Cell Biology

Background:

  • The CD8 molecule, present on thymocytes and cytotoxic T cells, exists as alpha/alpha homodimers or alpha/beta heterodimers.
  • CD8 functions as a coreceptor with the T cell receptor (TCR) to bind the MHC class I/peptide complex.
  • While CD8alpha/beta heterodimers are considered more effective coreceptors, the specific role of the CD8beta chain remains unclear.

Purpose of the Study:

  • To investigate the role of CD8beta in mediating CD8/MHC class I interactions.
  • To determine if CD8alpha/beta heterodimers exhibit enhanced cell-cell adhesion with MHC class I compared to CD8alpha/alpha homodimers.

Main Methods:

  • A cell-cell binding assay was employed to measure the adhesion capabilities of different CD8 forms to MHC class I.
  • Wild-type CD8alpha and CD8beta chains, as well as chimeric CD8beta-alpha homodimers, were utilized.

Main Results:

  • CD8alpha/beta heterodimers did not demonstrate greater cell-cell adhesion to MHC class I than CD8alpha/alpha homodimers.
  • Chimeric CD8beta-alpha homodimers showed no detectable binding to MHC class I.
  • The findings do not support enhanced binding of CD8alpha/beta to MHC class I compared to CD8alpha/alpha.

Conclusions:

  • The CD8beta chain's role is not mediated through increased binding affinity to MHC class I.
  • CD8beta may instead facilitate CD8/TCR interactions.
  • Alternative roles for CD8beta in signaling or regulatory pathways are suggested.

More Related Videos

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

Stability and Structure of Bat Major Histocompatibility Complex Class I with Heterologous β2-Microglobulin11:17

Stability and Structure of Bat Major Histocompatibility Complex Class I with Heterologous β2-Microglobulin

Published on: March 10, 2021

Related Concept Videos

Cell-mediated Immune Responses01:40

Cell-mediated Immune Responses

Overview
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 Processing Pathways01:31

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...
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...