FLOW CYTOMETRIC ANALYSIS OF INTRAEPITHELIAL LYMPHOCYTES IN THE HUMAN NASAL-MUCOSA

Recently, much research has been carried out on phenotypes and the function of intraepithelial lymphocytes of the intestines. However, only few studies have been made of nasal intraepithelial lymphocytes (nIEL), and the results have been controversial. We examined the population of different subsets of the human nIEL by means of 2-color flow cytometry after culturing lymphocytes isolated from the inferior turbinates of hypertrophic rhinitis in incubation media with monoclonal antibody against CD3. As a result, CD8+ cells (suppressor/cytotoxic T cells) and double negative T cells (CD8- CD4- T cells) were the most predominant. The CD4+ cells (helper/inducer T cells) to CD8+ cells ratio was 0.6. Cytotoxic T cells predominated over suppressor T cells in CD8+ cells and helper T cells predominated over inducer T cells in CD4+ cells. Double positive T cells (CD8+ CD4+ T cells) were nil and natural killer cells and CD8+ killer cells few. CD8+ cells and CD4+ cells were activated during cell culture. alpha-beta-receptor bearing T cells predominated over gamma-delta-receptor bearing T cells in CD8+ killer cells cells and CD+ cells but gamma-delta-receptor bearing T cells predominated over alpha-beta-receptor bearing T cells in double negative T cells. To investigate the effect of cell culture on the population of each phenotype of nIEL we also examined peripheral blood lymphocytes by flow cytometry before and after culture, and found that activated T cells markedly increased and suppressor T cells, gamma-delta-bearing T cells and natural killer cells slightly decreased. From the above results, it could be concluded that nIEL is heterogeneous in phenotype and characterized by a predominance of CD8+ cells, particularly cytotoxic T cells and double negative T cells with gamma-delta-receptor, which may be important for future study.