Figure 8.

Modulation of TNF production by HLA-E expression on target cells. PBMCs and SFMCs from arthritis patients were stimulated with K562 cells transfected with a cDNA plasmid encoding the HLA-E*01033 allele. HLA-E cell surface expression was stabilized by exogenous loading of the synthetic peptide VMAPRTVLL, encoded within the leader sequence of the HLA-B*0701(B7sp), or QMRPVSRVL encoded within the heat-shock protein 60 leader sequence (hsp 60sp). The frequency of NK cells (CD3^– CD56⁺ lymphocytes) producing TNF was assessed by flow cytometry using standard intracellular cytokine staining protocol, after 4 hr of coculture (n = 3–5). Lines connect paired samples from each patient identified with the same marker in all panels.