Liposome mediated affection of monocytes.

Dichloromethylene diphosphonate (Cl2MDP) enclosed in liposomes, when injected intravenously, selectively eliminates all phagocytizing macrophages that are in direct contact with the blood circulation of the spleen and the liver. We examined whether Cl2MDP containing liposomes affect, in addition, rat monocytes and bone marrow macrophage precursors (BMMP's). In addition to Phosphatidylcholine-Cholesterol liposomes (PC liposomes), we also used mannosylated PC liposomes (PCMAN liposomes), which are reported to bind more efficiently to macrophages.

Expression of the ED3 antigen on rat macrophages in relation to experimental autoimmune diseases.

Susceptibility to experimental autoimmune diseases (EAD) is rat strain dependent. Susceptible animals are reported to have a defective glucocorticoid response. Although many EAD are regarded as preferentially T cell-mediated, macrophages (M phi) play an important role in several different stages of these diseases.

Selective inhibition of immune complex trapping by follicular dendritic cells with monoclonal antibodies against rat C3.

The role of complement component C3 in the trapping of immune complexes by follicular dendritic cells (FDC) was studied in the rat, by means of the C3-specific monoclonal antibody ED11. Immunocytochemistry revealed the presence of C3 on FDC, where it co-localized with trapped peroxidase anti-peroxidase complexes. Furthermore, C3 was detected on reticular cells occupying the T cell areas of peripheral lymphoid organs, which are not involved in the handling of immune complexes.

Detection of migrated allogeneic oligodendrocytes throughout the central nervous system of the galactocerebrosidase-deficient twitcher mouse.

Galactocerebrosidase-deficient oligodendrocytes of 'twitcher' (twi/twi) mice degenerate prematurely. Transplantation of normal bone marrow cells has been shown to alleviate symptoms and to prolong survival time. However, characteristic ataxia ('twitching') is not cured.

Macrophages in experimental autoimmune diseases in the rat: a review.

In the pathogenesis of most experimental autoimmune diseases T lymphocytes play a crucial role in the initiation, whereas macrophages are essential in the effector phase. This review deals with several methods to elucidate the exact role macrophages play in different stages of autoimmune models in the rat. By using monoclonal antibodies an inventory has been made on the different macrophage subsets that are present in the infiltrates of the affected tissues.

Determination of the origin and nature of brain macrophages and microglial cells in mouse central nervous system, using non-radioactive in situ hybridization and immunoperoxidase techniques.

The origin and nature of brain macrophages and microglial cells in the mouse central nervous system (CNS) were investigated. First, the expression and localization of determinants recognized by the different monoclonal antibodies (mAbs) MOMA-1, Mac-1-alpha, and F4/80 (raised against cells of the mononuclear phagocyte system) were immunohistochemically studied in the developing and adult mouse brain. In order to clarify the origin of brain macrophages and microglial cells, we used bacteriophage lambda transgenic mice as donors for bone marrow transplantations in recipient mice of different ages.

Interferon-gamma induced IA antigen expression on cultured neuroglial cells and brain macrophages from rat spinal cord and cerebrum.

The inducibility of major histocompatibility complex class II (Ia) antigens on glial cells of the brain suggests that neuroglia have immunoregulatory functions within the central nervous system (CNS), i.e., recognition and presentation of antigens.

Cellular binding mechanism on rat macrophages for sialylated glycoconjugates, inhibited by the monoclonal antibody ED3.

The mAb ED3 recognizes a subpopulation of rat macrophages, with a highly restricted tissue distribution. The tissue distribution as well as the in vitro expression of the ED3 antigen and of the sheep erythrocyte receptor (SER), binding unopsonized erythrocytes in the mouse, are very similar. This receptor has almost the same binding characteristics, although a different tissue distribution, as the sialic acid binding receptor (SAR), binding ganglioside-coated erythrocytes in the rat.

Characterization and expression of the antigen present on resident rat macrophages recognized by monoclonal antibody ED2.

Because of the absence of a specific marker for labeling resident macrophages in the rat, there is almost no information available regarding the properties of individual resident macrophages in different organs. The recently described and in our laboratory developed mAb ED2, has been shown to exclusively recognize resident macrophages. The present study examines expression, function and structure of the ED2 antigen to obtain more information about the marker and therefore, more information about resident macrophages.

Glycosyl receptors in macrophage subpopulations of rat spleen and lymph node. A comparative study using neoglycoproteins and monoclonal antibodies ED1, ED2 and ED3.

We have developed an immunohistochemical method for the in vivo and in vitro detection of glycosyl receptors in rat spleen and lymph nodes by using neoglycoproteins. The receptor in both organs recognized mannose coupled to bovine serum albumin (mannose-BSA), fucose-BSA, N-acetylglucosamine-BSA and to a lesser extent glucose-BSA, but not galactose-BSA or N-acetyl-galactosamine-BSA. In vitro neoglycoprotein-receptor binding was Ca2+ dependent and could be inhibited by mannan but not by mannose.

Suppression of experimental allergic encephalomyelitis in Lewis rats after elimination of macrophages.

Almost 50% of the cells infiltrating the central nervous system (CNS) of animals with experimental allergic encephalomyelitis (EAE) are macrophages (M psi). To investigate the role of the M psi in the pathogenesis of EAE, we eliminated M psi by means of mannosylated liposomes containing dichloromethylene diphosphonate (Cl2MDP). Cl2MDP-containing liposomes injected intravenously eliminate M psi in spleen and liver.

Suppression of experimental allergic encephalomyelitis by intraventricular administration of interferon-gamma in Lewis rats.

Experimental allergic encephalomyelitis (EAE) is an autoimmune inflammatory disease of the central nervous system (CNS) which causes paralysis. Several studies have reported the involvement of Ia antigen-expressing cells in the pathogenesis of EAE. Interferon-gamma (IFN-gamma) can induce Ia antigen expression on a wide range of cells.

Mononuclear cells in glomeruli and cytokines in urine reflect the severity of experimental proliferative immune complex glomerulonephritis.

Immunohistochemical methods were used to investigate the role of macrophages in the progression of proliferative immune complex glomerulonephritis. The mononuclear cell component of glomerular inflammation was analysed in three different stages of chronic serum sickness, each of which was clearly distinguished by criteria of kidney function. Urinary excretion of the macrophage secretory products interleukin-1 and tumour necrosis factor was also evaluated in relation to the functional severity of kidney disease.

Depletion and repopulation of macrophages in spleen and liver of rat after intravenous treatment with liposome-encapsulated dichloromethylene diphosphonate.

Rats received a single intravenous injection with liposome-encapsulated dichloromethylene diphosphonate (C12MDP). This treatment resulted in the elimination of macrophages in spleen and liver within 2 days. Macrophages ingest the liposomes and are destroyed by the drug, which is released from the liposomes after disruption of the phospholipid bilayers under the influence of lysosomal phospholipases.

Heterogeneity of macrophages in the rat evidenced by variability in determinants: two new anti-rat macrophage antibodies against a heterodimer of 160 and 95 kd (CD11/CD18).

A set of three monoclonal antibodies (MoAbs), ED1, ED2, and ED3, has been shown to recognize in situ different subsets of macrophages in the rat. This macrophage diversity can be correlated with differences in stage of differentiation of cells belonging to one lineage. The present study quantifies this antigen distribution in the macrophage fractions of several lymphoid organs provided by Percoll centrifugation.

Isolation and characterization of brain macrophages from the central nervous system of newborn and adult rats and of rats with experimental allergic encephalomyelitis.

A method has been developed to isolate brain macrophages (M phi) from normal neonatal and adult rats brain cell suspensions, as well as from brain cell suspensions of rat with experimental allergic encephalomyelitis (EAE), by making use of the ability of M phi to adhere to plastic surfaces. The isolated adherent cells were immuno- and enzyme-cytochemically identified. Phagocytic activity and the presence of Fc-IgG receptors were also examined.

Marginal zone of the murine spleen in autotransplants: functional and histological observations in the response against a thymus-independent type 2 antigen.

Splenic tissue from mice was autotransplanted; after initial necrosis, a rapid restoration of implants into a structure histologically indistinguishable from splenic tissue was observed. The development of the marginal zone in these autotransplants, as determined with monoclonal antibodies against different splenic cell types and routine histological stains, was compared with the local and systemic response against a thymus-independent (TI) type 2 antigen. Full restoration of time course and peak of anti-trinitrophenyl (TNP) serum titres against TNP-Ficoll was observed at 4 weeks after autotransplantation.

Rat bone marrow and monocyte cultures: influence of culture time and lymphokines on the expression of macrophage differentiation antigens.

A set of seven monoclonal antibodies (moabs) has been shown to discriminate in situ between distinct subpopulations of macrophages in the rat. It is still controversial if this heterogeneity is caused by the existence of different lineages or by differentiation of a common precursor. In both cases, the differentiation process might be regulated by microenvironmental factors.

The heterogeneity of the reticulum of rat peripheral lymphoid organs identified by monoclonal antibodies.

We have developed a panel of six monoclonal antibodies, ED10-ED15, directed against reticular cells in peripheral lymphoid organs. Immunohistochemistry revealed prominent differences between these antibodies with regard to their tissue distribution in lymphoid and non-lymphoid organs. Furthermore, the determinants recognized by ED10-ED13 were found to be differentially expressed by reticular cells occupying the various specialized compartments present in peripheral lymphoid organs.