Evidence that macrophages are required for T-cell infiltration and rejection of fetal pig pancreas xenografts in nonobese diabetic mice

Abstract

Background. Host macrophages are abundant within fetal pig pancreas xenografts undergoing rejection, but their role is unknown. Therefore, we examined the effect of host macrophage depletion on xenograft rejection. Methods. Nonobese diabetic (NOD) mice were given clodronate-loaded liposomes intravenously to deplete macrophages. Controls received phosphate-buffered saline (PBS) or PBS-liposomes. General immune status was assessed after 2, 3, and 7 days by (1) fluorescence-activated cell sorter analysis of peripheral blood, spleen, and lymph node cells, (2) immunohistochemistry on spleens, and (3) mixed lymphocyte reaction. Organ-cultured fetal pig pancreas was transplanted under the kidney ca..