Related Experiment Videos
Cell-cell adhesion mediated by CD8 and human histocompatibility leukocyte antigen G, a nonclassical major
S K Sanders1, P A Giblin, P Kavathas
1Department of Laboratory Medicine, Immunobiology, and Human Genetics, Yale University School of Medicine, New Haven, Connecticut 06510.
Insights
The CD8 coreceptor binds to human histocompatibility leukocyte antigen (HLA)-G, a molecule found on placental cells. This finding suggests a potential interaction between CD8-bearing cells and HLA-G-expressing cells.
Area of Science:
- Immunology
- Molecular Biology
- Cell Biology
Background:
- CD8 is a lymphocyte differentiation marker functioning as a T cell receptor (TCR) coreceptor.
- CD8's known functions involve signaling via p56lck and adhesion to MHC class I through its alpha 3 domain.
- The binding of CD8 alpha/alpha homodimer to classical MHC class I molecules is established, but its interaction with nonclassical MHC molecules is less understood.
Purpose of the Study:
- To investigate whether CD8 can bind to nonclassical human histocompatibility leukocyte antigen (HLA)-G.
- To explore potential interactions between CD8-bearing cells and cells expressing HLA-G.
Main Methods:
- The study focused on demonstrating the binding capability of CD8 to HLA-G.
- Experimental methods were employed to assess the interaction between CD8 and HLA-G molecules.
Main Results:
- This report demonstrates that CD8 can bind to HLA-G.
- This binding occurs despite HLA-G being a nonclassical MHC molecule and its expression on placental cytotrophoblast cells, which lack classical HLA-A, -B, and -C molecules.
Conclusions:
- CD8 binding to HLA-G is demonstrated.
- This interaction opens the possibility for CD8-bearing cells to engage with cells expressing HLA-G, potentially impacting placental biology and immune interactions.
Abstract:
The lymphocyte differentiation marker CD8 acts as a coreceptor with the T cell receptor (TCR) during recognition of peptide presented by major histocompatibility complex (MHC) class I molecules. The functions of CD8 in the TCR complex are thought to be signaling through the association of CD8 with the protein tyrosine kinase p56lck and adhesion to MHC class I through the alpha 3 domain. While the ability of the CD8 alpha/alpha homodimer to bind to classical MHC class I molecules has been shown, it is unclear whether CD8 can also bind nonclassical molecules. Of particular interest is human histocompatibility leukocyte antigen (HLA)-G which is expressed on placental cytotrophoblast cells. These cells do not express HLA-A, -B and -C molecules. In this report, we demonstrate that CD8 can bind to HLA-G. It is possible, therefore, that a cell bearing CD8 may interact with HLA-G-expressing cells.