Cell-cell adhesion mediated by CD8 and human histocompatibility leukocyte antigen G, a nonclassical major histocompatibility complex class 1 molecule on cytotrophoblasts.
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.
Sanders
S K
SK
Department of Laboratory Medicine, Immunobiology, and Human Genetics, Yale University School of Medicine, New Haven, Connecticut 06510.
Giblin
P A
PA
Kavathas
P
P
D015703:Antigens, CD / Q000502:physiology*; D000945:Antigens, Differentiation, T-Lymphocyte / Q000502:physiology*; D016827:CD8 Antigens; D002448:Cell Adhesion; D015815:Cell Adhesion Molecules; D002460:Cell Line; D003001:Cloning, Molecular; D006680:HLA Antigens / Q000502:physiology*; D015789:HLA-A2 Antigen / Q000378:metabolism; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I / Q000502:physiology*; D006801:Humans; D066298:In Vitro Techniques; D008285:Major Histocompatibility Complex; D011485:Protein Binding; D014327:Trophoblasts / Q000166:cytology*
D015703:Antigens, CD; D000945:Antigens, Differentiation, T-Lymphocyte; D016827:CD8 Antigens; D015815:Cell Adhesion Molecules; D006680:HLA Antigens; D015789:HLA-A2 Antigen; D059951:HLA-G Antigens; D015395:Histocompatibility Antigens Class I