NSOM/QD-based nanoscale immune-fluorescence imaging of antigen-specific T cell receptor responses during an in vivo clonal Vγ2Vδ2 T cell expansion

Nanoscale imaging of an in vivo antigen-specific T cell immune response has not been reported. Here, the combined NSOMand fluorescent QD-based nanotechnology was employed to perform immune-fluorescence imaging of antigen-specific TCR response in an in vivo model of clonal T cell expansion. The NSOM/QD system provided a bestoptical-resolution nanoscale imaging of Vγ2Vδ2 TCR on the membrane of nonstimulated Vγ2Vδ2 T cells. Prior to Ag-induced clonal expansion, these non-stimulating Vγ2Vδ2 TCR appeared to be distributed differently from their αβ TCR counterparts on cell-surface. Surprisingly, Vγ2Vδ2 TCR nanoclusters not only were formed but also sustained on the membrane during an in vivo clonal expansion of Vγ2Vδ2 T cells after phosphoantigen treatment. The TCR nanoclusters could array to form nanodomains or microdomains on the membrane of clonally-expanded Vγ2Vδ2 T cells. Interestingly, expanded Vγ2Vδ2 T cells bearing TCR nanoclusters or nanodomains were able to rerecognize phosphoantigen and to exert better effector function. These studies provided nanoscale insight into the in vivo T cell immune response. 2 For personal use only. on August 16, 2017. by guest www.bloodjournal.org From