Implantation of exogenous enzymatic activity in isolated alveolar macrophages

Acquired heterophile antigens on the surface of human cell lines

Chicken IgM antibodies raised against sheep erythrocytes (SE) reacted with a heterophile carbohydrate antigen designated as "HC". This antigen was visualized by SE rosette formation with antibody-sensitized and formaldehyde-fixed target cells. Cells from eight lymphoblastoid lines and ten lines of diverse histogenetic origin all expressed HC on their surface to a greater or lesser degree when grown in fetal calf serum (FCS). Lymphoblastoid cell lines, HSB2 and Namalva, lost most of their HC antigen after three cell divisions when grown in medium which contained normal human serum (NHS) instead of FCS. The acquired origin of HC was demonstrated by the conversion of HSB2-HC- into HSB2-HC+ cells after incubation in the presence of FCS or fetuin for 18 h at 37 degrees C. The acquisition of HC antigen depended on the concentration of fetuin as well as the time and temperature of incubation. The presence of NHS in the culture medium reduced the degree of HC incorporation. The level of HC expressed on the cell surface was reduced by treating HSB2 cells with sodium periodate but not by proteolytic enzymes. Competitive inhibition with hog blood group substance and sheep IgG suggested similar specificity of HC on target cells which had been sensitized with either fetuin or sheep IgM (Eur. J. Immunol. 1977.7:204). The avidity of chicken antibodies to HC in either of these systems was several orders of magnitude lower than the binding to SE.

Potentiation of the macrophage response to migration inhibition factor from fetal calf serum by blood group substances with human H activity

Soluble blood group substances, with human H and A activity, have previously been shown to block the interaction between guinea pig peritoneal macrophages and migration inhibition factor from fetal calf serum (FCS-MIF). Conversely, incubation of macrophages at 37 degrees C for 1 h in the presence of 0.1% blood group substance, followed by thorough washing, potentiates the action of FCS-MIF. The sensitivity of the macrophages is markedly increased, allowing detection of subthreshold levels of FCS-MIF. Blood group substances (BGS) labeled with radioidine are taken up by macrophages, and a proportion remains on the surface. This radiolabeled BGS is lost from the surface spontaneously, and the rate of loss is increased by treatment with trypsin. It is suggested that the BGS mimic the natural macrophage receptor for FCS-MIF and potentiate its effect by incorporating new receptors into the macrophage membrane.

Intracellular edema and dehydration: effects on energy metabolism in alveolar macrophages

The effects of intracellular edema and dehydration on energy metabolism in alveolar macrophages were studied. Intracellular edema increased lactate production and reversibly decreased oxygen consumption. Dehydration caused no significant change in lactate production but irreversibly decreased oxygen consumption. These phenomena may be applicable to a wide variety of clinical problems including lung and brain edema.