Tracking the in vivo antigen specific T cell response to antigen administered via the ocular route

Purpose. Although lymphatic drainage of intraocular antigen has been demonstrated in the past, the extent of lymphatic drainage vs. splenic drainage and relative contribution to immune responses is unknown. In this study, we used a T cell receptor transgenic mouse system to track and functionally characterize the primary antigen specific T cell response to antigen administered through the ocular route. Methods. A limiting number of ovalbumin (OVA) peptide 323-339 specific T cells from the DO11.10 TCR transgenic mouse were transferred into normal BALB/c mice such that these cells were not the dominant population, but could be detected by flow cytometry or immunohistochemistry using the clonotypic mAb, KJ1-26. OVA was injected into the posterior chamber (pc) or variety of non-ocular sites and OVA specific T cells present in individual lymph nodes or spleen were quantitated by flow cytometry and localized by immunohistochemistry. The functional capability of the cells was determined in vitro by proliferation and cytokine assays. Results. Introduction of peptide or whole OVA into the pc of the right eye resulted in a dramatic expansion of OVA specific T cells primarily in the right submandibular lymph node and not spleen in three days. These cells proliferated vigorously to antigen plus APC's in vitro, secreted IL-2, and displayed high levels of CD44 indicating activation. Most of the OVA specific T cells were evenly dispersed throughout the lymph node, and some were in the lymphoid follicles. Immunohistochemistry also revealed foci of OVA specific T cells in the periarteriolar lymphoid sheaths of the spleen following pc injection. Conclusions. The primary response to antigen injected into the pc consists of a major expansion of antigen specific T cells in the draining, submandibular LN. These cells appear to be indistinguishable from the OVA specific T cells activated following subcutaneous OVA/CFA immunization. The OVA specific T cells observed in spleen by immunohistochemistry may represent a regulatory population of cells involved in ACAID.