CHEMOKINES ARE EXPRESSED DIFFERENTIALLY IN HUMAN CONJUNCTIVA IN VIVO
U. Spandau, F. Kruse, A. Toksoy, S. Verhaart, R. Gillitzer
Purpose: Inflammation of the conjunctiva is a common clinical problem, however, the factors which maintain the ocular inflammation and which are responsible for the recruitment of inflammatory cells are not fully understood. Therefore, we examined the expression of the CC chemokines MCP-1, RANTES and MIP-1 alpha, and the CXC chemokines MIG, IP-10, IL-8 and Gro-alpha with chemoattractive properties for specific leukocyte subsets in the inflammed conjunctiva.
Methods: Conjunctival tissue of 16 eyes, enucleated due to acute and chronic inflammation secondary to trauma was examined. In situ hybridization of the chemokines MCP-1, RANTES, MIP-1 alpha, MIG, IP-10, IL-8 und Gro-alpha was performed. Conjunctiva was immunohistologically stained with antibodies to demonstrate a correlation between chemokine mRNA expression and infiltrating leukocytes. Normal human eyes were examined as control. Results: The chemokines MCP-1, IL-8 and Gro-alpha were highly expressed in the hybridized conjunctival lesions. In contrast, all other examined chemokines (MIG, IP-10, MIP-1 alpha and RANTES) were moderatly expressed or barely detectable. All examined chemokines were expressed to some degree in conjunctival stroma. A high intensity of signals from MCP-1 and Gro-alpha was localized in the limbal epithelium. Only a few epithelial cells expressed MIG and IL-8 mRNA. Immunohistochemically stained lesions showed that Gro- alpha, MCP-1 and Il-8 were also expressed by infiltrating leukocytes and MIG mRNA was abundant in dense accumulations of T- lymphocytes.
Conclusions: These results demonstrate that chemokines are expressed differentially by human conjunctiva and indicate that Gro- alpha, MCP-1 and IL-8 might be important for the recruitment of leukocytes in inflammed conjunctiva. A selective inhibition of highly expressed chemokines may be of therapeutic benefit.
Augenklinik der Universität Heidelberg, INF 400, D-69120 Heidelberg
Hautklinik der Universität Würzburg, Josef Schneiderstrasse 2, 97080 Würzburg
University of the Witwatersrand, Medical School, Department of Pathology, York Road, Parktown, Johannesburg, South Africa