Proliferation of Macrophage Subpopulations in the Adult Rat: Comparison of Various Lymphoid Organs

Abstract

Adult male Lewis rats received a single intravenous injection of 5-bromo-2'-deoxyuridine (BRDU) to label all proliferating cells in the S-phase of the cell cycle. Various lymphoid organs were removed 1 and 24 hr after injection to assess local proliferation and migration of newly formed cells, respectively. In cell suspensions, surface staining was performed for macrophage subsets (ED1, ED2, ED3), and the DNA label BRDU was detected by a monoclonal antibody. Local proliferation of ED1+ macrophages occurred in all organs investigated with the exception of the blood. Bone marrow outweighed the other organs by far; in addition to the proliferating ED1+ promonocytes, the bone marrow also contained BRDU-labeled ED2+ macrophages. Newly formed ED1+ monocytes migrated into lymphoid organs such as the mesenteric lymph nodes and spleen where they comprised about 90% of newly formed macrophages. In the spleen, ED3+ macrophages seemed to be renewed by local proliferation, whereas in the mesenteric lymph nodes these cells were replaced by immigration. The heterogeneity of macrophages was further demonstrated by the different renewal of splenic macrophages. ED1+ and ED3+ cells were replaced in a matter of days, whereas it would probably take several months to renew ED2+ cells.

Fc- and Complement-Receptor Activation Stimulates Cell Cycle Progression of Macrophage Cells from G1 to S

“…Although most hemopoietic cells mature after leaving the bone marrow and cannot proliferate, local proliferation of mononuclear phagocytes has been observed (9,33). For example, macrophages resident in spleen and peritoneum were renewed by local proliferation (14,15). Furthermore, macrophages can replicate upon the stimulation of growth factors such as CSFs, and especially during inflammation (11).…”

Histological and Immunohistochemical Investigations of Hydroxyethyl Starch Deposits in Rat Tissues

“…To determine if HES-containing nonparenchymal cells belong to the mononuclear phagocyte system, we used the ED 1 antibody, a well-established monoclonal antibody re cognizing monocytes and macrophages of the rat [23][24][25], In consecutive sections of lymph node and spleen, which revealed the largest amount of HES-stained cells, labelling pattern of HES and EDI were superimposable. In these organs mainly MZM could be found to contain HES.…”

The fate of activated T cells migrating through the body: rescue from apoptosis in the tissue of origin

“…To exclude this, either activated mLN Tcells or activated pLN Tcells (both from LEW.7B rats) were injected into animals of a congenic strain (LEW.7A, [19]), and 3 days later the host animals received BrdUrd intravenously. By removing pLN and mLN 1 h later it was guaranteed that BrdUrd' cells had incorporated BrdUrd within the respective organ [26]. The congenic activated mLN and pLN Tcells were identified by immunohistochemistry (Fig.…”