The gap-junction protein connexin36 (Cx36) contributes to control the functions of insulin-producing cells. In this study, we investigated whether the expression of Cx36 is regulated by glucose in insulin-producing cells. Glucose caused a significant reduction of Cx36 in insulin-secreting cell lines and freshly isolated pancreatic rat islets. This decrease appeared at the mRNA and the protein l...

The switch from IgM to IgG (or IgA, IgE) synthesis has been studied in both normal and neoplastic Ig-secreting cells (1-6). Evidence suggests that DNA rearrangements precede isotype switching. The nature of the signals that induce isotype switching are not understood, although T cells (7-13), T cell-derived lymphokines (14-20), and mitogens (20-22) can influence switching in activated B cells. ...

The development of antibody-based drugs typically begins with the isolation and screening of thousands of antibody-secreting cells, often requiring 4-6 weeks to identify only 1-10 cell lines of interest. We are developing a novel immunobiosensing device to afford direct and rapid assessment of the antibody production of each of thousands of living cells captured on a single slide. Each cell sha...

Several transporting epithelia in vertebrates and invertebrates contain cells that are specialized for proton or bicarbonate secretion. These characteristic 'mitochondria-rich' (MR) cells have several typical features, the most important of which is an extremely high expression of a vacuolar-type proton-pumping ATPase (H+V-ATPase) both on intracellular vesicles and on specific domains of their ...

The gastric parietal (oxyntic) cell is presented as a model for studying the dynamic assembly of the skeletal infrastructure of cell membranes. A monoclonal antibody directed to a 95-kD antigen of acid-secreting membranes of rat parietal cells was characterized as a tracer of the membrane movement occurring under physiological stimuli. The membrane rearrangement was followed by immunocytochemis...