Ernst Peterhans

Murine glia cells in culture can be stimulated to generate reactive oxygen.

Induction of luminol‐enhanced chemiluminescence (CL) indicative of reactive oxygen formation was studied in glia cell cultures from newborn mice. A burst of CL could be induced by phorbol myristate acetate, zymosan, and antibody‐coated bovine red blood cells, whereas Sendai virus and several other agents known to induce CL in myeloid cells were ineffective. Sodium azide failed to inhibit CL, indicating a myeloperoxidase‐independent mechanism of light emission. In parallel experiments we identified the cells binding antibody‐coated erythrocytes as macrophages characterized by the reduction of nitroblue tetrazolium and phagocytosis of zymosan and latex particles. Brain macrophages may use reactive oxygen intermediates (ROI) as a mechanism of antimicrobial defence; and, on the other hand, ROI formed by these cells may contribute to immunopathology in the brain.

Evidence for different receptor sites in mouse spleen cells for the sendai virus hemagglutinin-neuraminidase (HN) and fusion (F) glycoproteins

Liposomes were reconstituted from phosphatidylcholine and Sendai virus glycoproteins HN or F and their interaction with mouse spleen cells was studied. Both the HN and F liposomes were able to stimulate chemiluminescence (CL), indicating that the glycoproteins were able to interact with the cell membrane independently of each other. The induction of CL in cells which had been pretreated with liposomes by monoclonal antibodies to either HN or F demonstrated that HN and F bind to the cells independently. The presence of F liposomes on the cell surface was also confirmed by immunoelectron microscopy. Cells pretreated with HN and F liposomes revealed a different pattern of CL when challenged with intact virus or the calcium ionophore A23187 indicating that HN and F bind to different receptor sites.

Detection of H-2 and Sendai virus antigens by chemiluminescence.

Two monoclonal antibodies reacting with Ia9 and H2.2, respectively, have been added to spleen cell suspensions prepared from mice of different H-2 haplotypes. Cellular light emission was monitored in a liquid scintillation spectrometer operated in the out-of-coincidence mode. The antibodies stimulated chemiluminescence (CL) in cells possessing the target antigenic determinant, but were inactive in cells lacking the determinant. In addition, CL could be stimulated in Sendai virus-infected spleen cells with anti-Sendai antibodies. The results demonstrate that CL measurement is a sensitive and simple method for the detection of cell surface antigens and for the screening of antibodies reacting with these antigens.

Functional state of cultured chick embryo cell mitochondria investigated in situ.

Abstract The cell membrane of cultured chick embryo cells is permeable to Ca 2+ after treatment with mannitol. Ca 2+ uptake by mannitol-treated cells can be attributed to the mitochondria. Ca 2+ O quotients and acceptor control ratios of such cells and isolated mitochondria are identical. Digitonin exerts two time-dependent effects on mannitol-treated cells: it increases the maximum extent of Ca 2+ uptake by 5 – 20 percent. It also partially uncouples respiration from Ca 2+ accumulation. It is suggested that mannitol treatment of cultured cells provides an easy way to study Ca 2+ uptake by mitochondria in situ .