Study of Pro-inflammatory Cytokines in Endotoxin Induced Uveitis

ABSTRACT

Cytokines are produced during the effector phases of natural and specific immunity and serve to mediate and regulate immune and inflammatory responses. In natural immunity,endotoxin directly stimulates mononuclear phagocytes to secrete their cytokines and cytokines which were produced by one cell type often regulate the synthesis of cytokined by other cells. To gain effects on the role of pro-inflammatoy cytokines(TNF, IL-1, IL-6) in the endotoxin induced uveitis, author investigated the cell counts of infilterating inflammatory cells, IL-6 bioassay in aqueous humor, mRNA analysis in the transgenic endotoxin induced uveitic mice(TNF-R(-), IL-1R(-), TNF-R(-)/IL-1R(-)). In this study, there was no significant difference in the number of infiltering cells in TNF-R(-) mice compared to congenic controls, but significant diffetence in the unmber of infiltering cells was found in IL-1R(-) and TNF-R(-)/IL-1R(-) mice. IL-6(-) levels in aqueous humor were reduced in IL-1R(-) and TNF-R(-)/IL-1R(-) mice. TNF-alpha, IL-1alpha, IL-6 mRNA were detected in all experimental mice after endotoxin injection. IL-1alpha and IL-1Ralpha mRNA were detected in noninjected TNR-R(-) mice. IL-1beta mRNA was not detected in all experimental mice without or with endotoxin injection. In conlclusion, IL-1 appears to have a more important role in endotoxin induced uveits than TNF. Though IL-6 is detected in endotoxin induced uveitis, it is not an indicator for the enhenceing inflammation and may not be essential for the endotoxin induced uveitis.