ROLE OF GAMMA-DELTA-T CELLS IN THE PALATINE TONSIL

gamma delta-T cells in the tonsil were evaluated by flow cytometric an alysis and immunohistological study using monoclonal antibodies to the gamma delta-T cell receptor. Flow cytometric analysis using TCR-gamma /delta-1 showed that 2.2% of T cells in the tonsil obtained from patie nts with recurrent or chronic tonsillitis expressed the gamma delta-T cell receptor. Immunohistologically, gamma delta-T cells were found ma inly in the extrafollicular area, i.e., the T-cell zone, and showed st rong migration to the crypt epithelium in tonsils with infections. The comparison on number of gamma delta-T cells in cases with simple hype rtrophic tonsil and in cases with recurrent or chronic tonsillitis sho wed that tonsils with repeated or chronic infections had a significant ly greater number of gamma delta-T cells than tonsils without infectio n. To address the Functional aspects of gamma delta-T cells in the ton sil, the production of IL-2 of separated gamma delta-T cells was measu red by solid phase ELISA. Increased IL-2 production was observed with staphylococcal enterotoxin A and B stimulation, and this increase was blocked by antibody to the gamma delta-T cell receptor, indicating tha t the production of IL-2 may be triggered by the interaction between t he gamma delta-T cell receptor and staphylococcal enterotoxin. Our res ults show that gamma delta-T cells in the tonsil, especially in the cr ypt epithelium, may be activated by various bacterial antigens or heat shock protein released from damaged epithelial cells. The activated g amma delta-T cells will produce cytokines including IL-2 and function as so-called 'first-layer' immunity.