[HTML][HTML] Effect of macrophage depletion on immune effector mechanisms during corneal allograft rejection in rats
TPAM Slegers, PF Torres, L Broersma… - … & visual science, 2000 - arvojournals.org
TPAM Slegers, PF Torres, L Broersma, N van Rooijen, G van Rij, R van der Gaag
Investigative ophthalmology & visual science, 2000•arvojournals.orgpurpose. In rats, corneal allograft rejection is delayed for at least 100 days by clodronate
liposomes. These liposomes selectively deplete macrophages. To investigate the
immunologic basis for absence of graft rejection in treated rats, the effect of these liposomes
on the generation of cytotoxic T lymphocytes (CTLs) and antibody production after orthotopic
corneal allotransplantation was determined. methods. Transplantations of corneal buttons
from PVG rats were performed in AO rats. After surgery, one group received clodronate …
liposomes. These liposomes selectively deplete macrophages. To investigate the
immunologic basis for absence of graft rejection in treated rats, the effect of these liposomes
on the generation of cytotoxic T lymphocytes (CTLs) and antibody production after orthotopic
corneal allotransplantation was determined. methods. Transplantations of corneal buttons
from PVG rats were performed in AO rats. After surgery, one group received clodronate …
Abstract
purpose. In rats, corneal allograft rejection is delayed for at least 100 days by clodronate liposomes. These liposomes selectively deplete macrophages. To investigate the immunologic basis for absence of graft rejection in treated rats, the effect of these liposomes on the generation of cytotoxic T lymphocytes (CTLs) and antibody production after orthotopic corneal allotransplantation was determined.
methods. Transplantations of corneal buttons from PVG rats were performed in AO rats. After surgery, one group received clodronate liposomes subconjunctivally at five time points, and the other group remained untreated. On postoperative day (POD) 3, 7, 12, or 17, rats were killed, the presence of CTLs was investigated at three different anatomic locations, and antibodies against donor antigens were tested.
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.
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