Immunohistochemical Study of Immune Cells, with a Special Emphasis on Macrophage Subpopulations in the Rat Thymus after Cyclophosphamide Treatment / 대한해부학회지

ABSTRACT

This study was undertaken to investigate the in vivo effects of cyclophosphamide (CY) on immune cells, with a special emphasis on macrophage subpopulations in the thymus of rats. After a single dose of CY (150 mg/kg) was administered to Sprague-Dawley rats by intraperitoneal injection, the rats were sacrificed at days 1, 3, 7, 14 and 28. The immunohistochemical characterization of the tissues were carried out using various monoclonal antibodies in cryostat-cut sections. CD4(+/-) and CD8(+/-) T cells were greatly decreased in number after CY treatment. However, macrophages, including the ED1(+/-) ED2(+/-) and ED3(+/-) macrophages exhibited signs of cellular activation such as an increase in number and size of cell, and an upregulation of the ED1, ED2 and ED3 reactive surface molecule expression. Contrarily, CY elicited a decrease in number of thymic dendritic cells (DCs). CY induced a conspicuous upregulation of ICAM-1 expression in the thymic cortex. Most of these features began to detectable from the first day and reached the maximun on the third and seventh days, but two weeks after CY administration, these phenomena began to disap. In conclusion, the results of the present study shed more light on the effects of CY on various subpopulations of macrophages and other types of immune cells and on ICAM-1 expression in the rat thymus.