Intra-epithelial lymphocytes and non-lymphoid cells in the human nasal mucosa

Immunohistochemical staining of biopsy specimens was used to investigate the occurrence of lymphocyte subsets and non-lymphoid cells within the epithelial layer of the human nasal mucosa. The CD19 (B cell) marker was not expressed on the intra-epithelial lymphocytes, whereas the pan T cell marker CD2 was varyingly detected. The HLA-Dr antigen was abundantly present on epithelial cells, lymphocytes, and non-lymphoid cells. The latter are probably dendritic or Langerhans' cells. The findings stated above were the same in patient and control samples. In biopsy sections of 9 ear, nose, and throat patients, many CD8-positive (T suppressor/cytotoxic) cells and very few weakly stained CD4-expressing (T helper/inducer) cells were present. Quantification on single-cell preparations showed an average of 67% of the lymphocytes to be CD2 positive, 73% to be CD8 positive, while only 12% of the lymphocytes expressed the CD4 antigen. In control sections CD8 was similarly present as in patient sections, and, in addition, some clearly stained CD4-positive cells were seen.