Characterization of NR10 sub(2) macrophages

Transfection of cells with nitrate reductase (NR) gene fragments from the barley plant was initially undertaken in our laboratory in an effort to intracellularly diazotize biosynthetic aminomelanin, thus allowing formation of diazoluminomelanin (DALM) in situ. DALM is a thermochemiluminescent polymer used primarily for microwave dosimetry. One serendipitous finding of our initial work in this area was that murine macrophage cell lines, especially RAW 264.7, transfected with barley NR gene fragments, exhibited enhanced nitrite production when nitrate and very low doses of interferon-gamma (IFN- gamma ) and lipopolysaccharide (LPS) were added to the culture medium. The most promising of these transfected RAW 264.7 cell lines, known as NR10 sub(1), NR10 sub(2), and NR800 sub(5), are patented (U.S. Patent No. 5,464,768) and available from the American Type Culture Collection (ATCC numbers CRL 11771 through 11773). Outside of our interest in producing intracellular DALM for microwave dosimetry, we have pursued experiments designed to yield a greater understanding of the impact of elevated nitrite (and other nitrogen oxides; NOx) levels on cells, because NOx may be a factor in microwave-cell interaction studies.