The role of lymphokines in immunogenic uveitis

Lymphokines were prepared from rabbit lymph node cells specifically activated in vitro with the insoluble antigen ovalbumin or nonspecifically activated with the insoluble mitogen concanavalin A. Intravitreal injection of either lymphokine caused uveitis in the normal rabbit eye, more severe and more prolonged with the concanavalin A-activated supernatants than with the ovalbumin-activated supernatants. The most striking difference between the two lymphokine preparations was in their ability to induce a secondary intraocular antibody response in the trinitrophenyl bovine gamma globulin-primed recipient. Concanavalin A supernatants stimulated polyclonal B cell activation with appreciable anti-TNP responses in animals primed either systemically or locally. In contrast, ovalbumin supernatants stimulated an intraocular anti-TNP response only in those animals that had been primed within the eye. We speculate that two or more different lymphokines are active, some of which attract lymphocytes nonspecifically to the local site and others of which excite polyclonal B cell activation and plasma cell formation.