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A comparative study of the characteristics of intraepithelial and lamina propria lymphocytes of the human nasal mucosa
Author(s) -
Pawankar R.,
Okuda M.
Publication year - 1993
Publication title -
allergy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.363
H-Index - 173
eISSN - 1398-9995
pISSN - 0105-4538
DOI - 10.1111/j.1398-9995.1993.tb00693.x
Subject(s) - lamina propria , intraepithelial lymphocyte , biology , immune system , cd8 , immunology , pathology , population , lymphocyte , epithelium , medicine , environmental health
The phenotypes and receptors of the intraepithelial lymphocytes which are a major component of the mucosal immune system are of considerable interest. Intraepithelial lymphocytes, especially those of the intestines, are well documented. The nasal intraepithelial lymphocytes probably play a key role in the immune defense of the entire respiratory tract. However, documentation of these lymphocytes is limited to only a few nondescriptive studies by immunohistological methods. In our previous paper, we examined the subsets of the nasal intraepithelial lymphocytes by two‐color flow cytometry after culture with monoclonal antibody against CD3 and PMA. The mucosal immune system, which comprises the lymphoid tissue associated with the mucosal surface, consists of lymphocyte populations from both the epithelium and the lamina propria. In this paper (a sequel to our previous study), we have carried out a comparative study of the intraepithelial lymphocytes and lamina propria lymphocytes of the human nasal mucosa. In the 42 patients (with allergic rhinitis/infectious hypertrophic rhinitis) whom we examined, T lymphocytes were predominant in the epithelium as well as the lamina propria. B lymphocytes were detected only in the lamina propria. CD8 + T cells (suppressor/cytotoxic) and CD4‐8 ‐(double‐negative) (DN) comprised the major population of the intraepithelial lymphocytes. The CD4+/CD8+ ratio was 0.5 ± 0.1. In contrast, the lamina propria showed a predominance of CD4 + T cells (helper/inducer), with a CD4 +/CD8 + ratio of 1.3 ± 0.2. CD3 + 4–8‐(double‐negative T cells) were comparable in number in the epithelium and the lamina propria. CD8 + T cells of the epithelium were predominantly cytotoxic T cells, and CD4 + T cells were predominantly helper T cells. In the lamina propria, CD8 + T cells were predominantly of the suppressor type. In the analysis of the T‐cell receptors of the epithelium and the lamina propria, there was a predominance of the αβ receptor‐bearing T cells in both. However, in the double‐negative T‐cell population of the epithelium, γδ heterodimer predominated over αβ. In order to verify the influence of culture conditions on the percentages of the individual subsets of lymphocytes, we examined the peripheral blood lymphocytes by flow cytometry before and after culture under the same conditions. We found no significant change in the different subsets caused by culture except a slight reduction in the percentage of suppressor T cells as well as a significant increase in activated T cells. We therefore wish to emphasize that the nasal intraepithelial lymphocytes are heterogenous in phenotype, and are dominated by double‐negative cells and CD8 + T cells. Moreover, the nasal lamina propria lymphocytes are also heterogenous in phenotype, and differ in proportion from the intraepithelial lymphocytes. What is of utmost interest is the preferential location of the γδ receptor‐bearing T cells in the epithelium and their relative absence in the lamina propria.