Effect of macrophage depletion on immune effector mechanisms during corneal allograft rejection in rats.

RESULTS. No significant differences were found between the groups tested 3 and 7 days after surgery. But on POD 12 (the time of onset of rejection in the untreated group) and on POD 17, the CTL activities detected in the submandibular lymph nodes (P # 0.008) and the spleen (P # 0.009) were significantly less in the treated groups compared with the untreated groups. In the untreated groups complement-independent antibodies were present only on POD 17, whereas no antibodies were found in the treated rats. CONCLUSIONS. Local treatment with clodronate liposomes was shown to downregulate local and systemic CTL responses and to prevent the generation of antibodies. Local depletion of macrophages in the initiation phase of the immune response appears to lead to a less vigorous attack on the grafted tissue and therefore to promote graft survival. (Invest Ophthalmol Vis Sci. 2000;41: 2239 ‐2247)