Inhibition of Lymphocyte Adherence to Rat Lacrimal Acinar Epithelium by Interleukin-4 and Transforming Growth Factor-β

Mature circulating lymphocyte populations specifically bind to lacrimal gland acinar epithelium in vitro and this adherence is thought to contribute to the accumulation of lymphoid subsets within lacrimal tissue in vivo. The regulatory role of interleukin-4 (IL-4) and transforming growth factor-β (TGF-β) in this adherence process was examined using an in vitro binding assay. Pretreatment of thoracic duet lymphocytes (TDLs) with increasing concentrations of IL-4 or TGF-β for 1 hr resulted in a dose-dependent inhibition of lymphocyte binding to lacrimal gland acinar epithelium. In contrast, the binding of TDLs to high endothelial venules of cervical lymph node was not inhibited by either cytokine. Further, IL-4 and TGF-β pretreatment did not alter the expression of lymph node or Peyerʹs patch homing receptors as well as the LFA-1, VLA-4, or CD44 adhesion molecules on TDLs. These results suggest that the interaction of lymphocytes with lacrimal gland acinar epithelium may be regulated by a receptor-mediated mechanism that differs from those governing HEV recognition.