BACKGROUND: In uveal melanoma, both the amount of tumor-infiltrating cells and the level of expression of HLA antigens are quite variable. We hypothesized that low levels of HLA expression lead to a lack of antigen presentation, which might prevent proper immunologic recognition of the tumor. This lack of recognition might subsequently lead to low levels of tumor-infiltrating cells. METHODS: To test this hypothesis, we determined the type and number of tumor-infiltrating cells in tumor sections from 24 uveal melanomas. We applied monoclonal antibodies directed against different types of immune cells and compared the results with the expression of HLA class I and class II antigens on the tumor cells. RESULTS: Infiltrating immune cells were observed in all uveal melanomas (although in small amounts), with a predominance of T lymphocytes. Significant positive correlations were observed between the number of CD3+ cells (T lymphocytes) and monomorphic HLA class I expression, allele-specific HLA-A2 and Bw4 expression, and HLA class II expression. Furthermore, the number of CD4+ cells (T helper cells, monocytes/ macrophages) and of CD11b+ cells (monocytes/macrophages) was significantly correlated with the level of monomorphic HLA class I expression. CONCLUSION: These data support our hypothesis that low levels of HLA expression (and therefore a lack of presentation of tumor-specific antigens) may lead to a low level of tumor infiltrate.
BACKGROUND: In uveal melanoma, both the amount of tumor-infiltrating cells and the level of expression of HLA antigens are quite variable. We hypothesized that low levels of HLA expression lead to a lack of antigen presentation, which might prevent proper immunologic recognition of the tumor. This lack of recognition might subsequently lead to low levels of tumor-infiltrating cells. METHODS: To test this hypothesis, we determined the type and number of tumor-infiltrating cells in tumor sections from 24 uveal melanomas. We applied monoclonal antibodies directed against different types of immune cells and compared the results with the expression of HLA class I and class II antigens on the tumor cells. RESULTS: Infiltrating immune cells were observed in all uveal melanomas (although in small amounts), with a predominance of T lymphocytes. Significant positive correlations were observed between the number of CD3+ cells (T lymphocytes) and monomorphic HLA class I expression, allele-specific HLA-A2 and Bw4 expression, and HLA class II expression. Furthermore, the number of CD4+ cells (T helper cells, monocytes/ macrophages) and of CD11b+ cells (monocytes/macrophages) was significantly correlated with the level of monomorphic HLA class I expression. CONCLUSION: These data support our hypothesis that low levels of HLA expression (and therefore a lack of presentation of tumor-specific antigens) may lead to a low level of tumor infiltrate.
Authors: Long V Ly; Inge H G Bronkhorst; Els van Beelen; Johannes Vrolijk; Andrew W Taylor; Mieke Versluis; Gregorius P M Luyten; Martine J Jager Journal: Invest Ophthalmol Vis Sci Date: 2010-06-10 Impact factor: 4.799
Authors: D J Blom; L R Schurmans; I De Waard-Siebinga; D De Wolff-Rouendaal; J E Keunen; M J Jager Journal: Br J Ophthalmol Date: 1997-11 Impact factor: 4.638
Authors: Julia Woodward; Karen Sisley; Graham Reeves; Carmel Nichols; M Andrew Parsons; Hardeep Mudhar; Ian Rennie Journal: Int J Exp Pathol Date: 2004-02 Impact factor: 1.925
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