Direct binding of the Mtv7 superantigen (Mls-1) to soluble MHC class II molecules.
The superantigen encoded by the mouse mammary tumor virus (MMTV) is a potent stimulator of T cells when bound to MHC class II molecules. Recent data from this laboratory have shown that the Mtv7 superantigen, Mls-1, elicits a strong T cell response when presented by HLA-DR. To expand these observations further, we have produced the 28 kDa extracellular domain and the 18 kDa carboxy-terminal subfragment of the Mls-1 protein in E. coli and studied their interaction with human MHC class II molecules in vitro. In this report, we demonstrate direct binding of these recombinant forms of the Mls-1 protein to soluble HLA-DR1 and HLA-DR4, but not to HLA-A2. Our data imply a unique class II interaction site of retroviral superantigens that is not shared with bacterial superantigens.
Mottershead
D G
DG
Department of Pathology, Tufts University School of Medicine, Boston, Massachusetts 02111.
Hsu
P N
PN
Urban
R G
RG
Strominger
J L
JL
Huber
B T
BT
D000818:Animals; D000956:Antigens, Viral / Q000378:metabolism; D001483:Base Sequence; D001665:Binding Sites; D004926:Escherichia coli / Q000235:genetics; D000949:Histocompatibility Antigens Class II / Q000378:metabolism*; D006801:Humans; D051379:Mice; D016747:Minor Lymphocyte Stimulatory Antigens / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D008969:Molecular Sequence Data; D010957:Plasmids; D011994:Recombinant Proteins / Q000378:metabolism
D000956:Antigens, Viral; D000949:Histocompatibility Antigens Class II; D016747:Minor Lymphocyte Stimulatory Antigens; D011994:Recombinant Proteins