SUMMARY
The intraepithelial lymphocytes (IELs) may play an important role in the defense and tolerance induced by the mucosal associated lymphoid tissue (MALT). In the mucosal epithelium, IELs express the human mucosal lymphocyte integrin (HML-1), which is important in their adherence to the epithelial cells. In this experiment, the authors investigate the mechanisms of HML-1 expression on peripheral blood lymphocytes associated with corneal limbal epithelium.
Lymphocitic and corneal epithelial cultures were performed. Three groups were determined: Group A, non-activated lymphocytes with corneal limbal epithelial cells in culture media; Group B, nonactivated lymphocytes separated by a semi-permeable membrane from epithelial cells in culture media; and group C, non-activated lymphocytes in culture media (control). In the seventh day, the lymphocytes were recovered and sent to jlow citometric analysis of the antigens CDS/HML-1, CD3/CD8, CD3/CD4, CD3/CD25, CD8/CD25 and CD4/CD25.
Comparisons amongst groups A, B and C were dane by the repeated-measured statistical anaiysis (ANOVA) and Student's paired -t test.
Statistically significant differences were observed in the following lymphocytic sub-populations: CD8/HML-1 + (p=0,001), CD3/CD8+ (p=0,006), CD3/CD25+ (p=0,023) e CD8/CD25+ (p=0,002).
This experimental study suggests that the HML-1 expression by the CD8+ peripheral T lymphocytes increase may be dependent upon direct and indirect interactions with corneal epithelium. Growth factors and cytokines may play a role in HML-1 expression.