Effects of Cyclosporin A on Popliteal Lymph Node Graft－versus－Host Reaction in Rats

The immunosuppressive effect of cyclosprin A (CYA) was studied in the popliteal lymph node graft-versus-host (GvH) reaction. Viable lymph node cells from DA rats were injected into foot pad of (DA×Lou/M)F1 hybrids and popliteal lymph nodes were weighed 7 days later. In vivo treatment of F1 hybrids with 7-days course of CYA, which was given intraperitoneally at the dose of 20 mg/kg body weight, suppressed this local GvH reaction started at the time of cell transfer. However, neither in vivo treatment of F1 hybrids with CYA for 7 days before cell transfer, in vitro incubation of the cellular inosulum with CYA, nor the inoculation of lymph node cells form CYA-treated donors affected the local GvH reaction. Examination of the popliteal lymph nodes undergoing a GvH reaction by immunoperoxidase-staining revealed a disorganization of the lymph node architecture with disappearance of the follicles, and the increase of Ia+ (OX6+) cells in both paracortex and medulla. In the flow cytofluarometric analysis, the relative increase of Ia+ cells was observed, and the percentage of T helper (Th

Cyclosporin A

Local GvH reaction

Monoclonal antibody

Flow cytofluorometry

Immunohistochemistry