Vgamma9Vdelta2 T cells recovered from eyes of patients with Behçet's disease recognize non-peptide prenyl pyrophosphate antigens

The phenotype and antigen-specificity of T cells expanded by mitogenic stimulation from intra-ocular fluid (IOF) samples of affected eyes of six Behçet's disease (BD) patients, and seven patients with other uveitis entities, were determined. High numbers of gammadelta T cells, predominantly Vgamma9Vdelta2 T cells, were only detected in the IOF-derived TCL of three BD patients. Whereas no TCL responded to heat shock protein (HSP) 65 kDa, reactivity to isopentyl pyrophosphate (IPP) and related non-peptide prenyl pyrophosphates (PPP) was restricted to the gammadelta T cell containing TCL. Upon IPP stimulation, these TCL secreted IFN-gamma but no IL-4. By single-cell analysis of intracellular IFN-gamma production and CD69 expression the IOF-derived IPP-specific T cells were identified as CD4(-)CD8(-) gammadelta T cells. The data presented suggest the infiltration of PPP-specific Vgamma9Vdelta2 Th1-like cells into the eye of BD patients with uveitis.