Figure 4.
The CD1d T322A/S323A double mutant is more resistant to the down-regulation of CD1d-mediated antigen presentation caused by a herpes simplex virus type 1 (HSV-1) infection than wild-type (WT) CD1d. HEK293 cells expressing WT CD1d, or the T322A, S323A and T322A/S323A mutants were infected with HSV-1 at a multiplicity of infection (MOI) of 2 for 4 hr. The cells were then fixed with 0·05% paraformaldehyde and co-cultured with human NKT cells (105/well, E:T = 1 : 1) for 48 hr. The supernatants were analysed for granulocyte–macrophage colony-stimulating factor (GM-CSF) production by ELISA. The data are shown as the percentage of mock-treated cells (mock = 100%). *P < 0·05.