T cell-antigen-presenting cell interactions visualized in vivo in a model of antigen-specific inflammation.

Videomicroscopy is being used increasingly to characterize the interaction of T cells and antigen-presenting cells (APCs) within lymphatic tissues but has not been reported, to our knowledge, at sites of inflammation. We employed intravital videomicroscopy to study an anterior uveitis model using DO11.10 T cells and ovalbumin (OVA). T cell movement in iris was consistent with a random walk independent of the presence of recognized antigen and had a lateral speed slower than T cells in lymph node. Lingering of T cells adjacent to APCs suggested that they were physically interacting. This apparent contact demonstrated antigen specificity when comparing results from DO11.10 cells with OVA versus bovine serum albumin (BSA) loaded APCs but not when comparing results from OVA-loaded APCs with DO11.10 versus HA clonotype 6.5 T cells. Further studies with this model system should clarify the contribution of T cell-APC communication at a site of inflammation, infection, or immunization.