FIGURE 6.

Ganciclovir (GCV) induces sustained reduction of Gr-1+ myeloid cells in allografts but not in spleen and does not influence the intragraft alloimmune response. (A) Gr-1+ cells were analyzed by flow cytometry in cytomegalovirus (CMV), GCV, and post-GCV allografts. Gr-1 cells decreased in GCV grafts compared with CMV grafts (P<0.05) and remained low after GCV was discontinued (GCV vs. post-GCV, P>0.05, ns). Post-GCV Gr-1+ numbers remained lower than those found in CMV grafts without GCV treatment (P<0.01). (B) Gr-1 cells were analyzed by flow cytometry in spleens from Mock, CMV, GCV, and post-GCV animals to determine whether GCV treatment induces neutropenia. Numbers of Gr-1+ cells were similar in spleens from animals with and without GCV treatment, indicating that GCV did not induce global neutropenia in the host animals. Mock animals were given cyclosporine (white bars), no treatment (checkerboard bars), or GCV without cyclosporine (diagonal hatched bars), and allografts were analyzed for CD45+ (C) and CD11b+ (D) infiltrates. Cyclosporine reduced the alloimmune-associated infiltrates compared with untreated grafts (P<0.05), but GCV did not reduce the alloimmune response in cyclosporine-untreated, CMV-negative animals compared with those not receiving GCV (ns).