Efferent blockade of delayed-type hypersensitivity responses in the anterior chamber of the eye.
Syngeneic P91 mastocytomas undergo immunological rejection in the eyes of DBA/2 hosts by a process involving ischemic necrosis. Histopathological features of the ischemic necrotizing pattern of tumor rejection are consistent with a delayed-type hypersensitivity (DTH) effector mechanism. The present study sought to determine if selective depletion of cytotoxic T lymphocyte (CTL) or DTH effector functions by in vivo treatment with either CD8+ or CD4+ monoclonal antibodies would convert the pattern of tumor rejection from an ischemic necrosis DTH-like pattern to a piecemeal necrosis, CTL-like pattern. In vivo treatment with anti-CD4 antibody resulted in the elimination of both CTL and DTH responses, yet the intraocular tumor underwent a characteristic ischemic necrotizing pattern of rejection. By contrast, treatment with anti-CD8 antibody eliminated CTL activity without diminishing DTH responses. Surprisingly, intraocular tumors grew progressively in these hosts even though intense tumor-specific systemic DTH responses were demonstrable. Collectively, the results indicate that classical DTH effector mechanisms mediated by CD4+ T cells are either actively excluded from the intraocular milieu or are suppressed within the eye.
Niederkorn
J Y
JY
Department of Ophthalmology, University of Texas Southwestern Medical Center, Dallas 75235.
Benson
J L
JL
Mayhew
E
E
D000818:Animals; D000867:Anterior Chamber / Q000276:immunology*; D015704:CD4 Antigens; D005260:Female; D006084:Graft Rejection / Q000276:immunology; D006968:Hypersensitivity, Delayed; D007108:Immune Tolerance; D008212:Lymphocyte Depletion; D012515:Mast-Cell Sarcoma / Q000276:immunology; D051379:Mice; D008811:Mice, Inbred DBA
D015704:CD4 Antigens