Data from: Empty conformers of HLA-B preferentially bind CD8 and regulate CD8+ T cell function

When complexed with antigenic peptides, human leukocyte antigen (HLA)
class I (HLA-I) molecules initiate CD8+ T cell responses via interaction
with the T cell receptor (TCR) and co-receptor CD8. Peptides are generally
critical for the stable cell surface expression of HLA-I molecules.
However, for HLA-I alleles such as HLA-B35:01, peptide-deficient (empty)
heterodimers are thermostable and detectable on the cell surface.
Additionally, peptide-deficient HLA-B35:01 tetramers preferentially bind
CD8 and to a majority of blood-derived CD8+ T cells via a CD8-dependent
binding mode. Further functional studies reveal that peptide-deficient
conformers of HLA-B35:01 do not directly activate CD8+ T cells, but
accumulate at the immunological synapse in antigen-induced responses, and
enhance cognate peptide-induced cell adhesion and CD8+ T cell activation.
Together, these findings indicate that HLA-I peptide occupancy influences
CD8 binding affinity, and reveal a new set of regulators of CD8+ T cell
activation, mediated by the binding of empty HLA-I to CD8.