A new monoclonal antibody to study mouse macrophage antigen during BHT-induced lung injury and repair

A rat monoclonal antibody 133-13A to a mouse lung carcinoma cell line was found to react with macrophages in mouse lung [1]. This monoclonal antibody is different from previously described antibodies to macrophages. Immunogold electron-microscopy and immunoperoxidase light microscopy have been used to show that MoAb 133-13A binds specifically to macrophages in normal and in BHT treated mouse lungs. This MoAb recognizes a protein of approximately 100 kDa (P100) on cultured lung carcinoma cells and a 87 kDa protein on macrophages from lung or the peritoneal cavity which is different from other marcophage using immunoaffinity chromatography. The purified protein was radioiodinated and MoAb 133-13A was used to develop a competition radioimmunoassay to quantitate P100. Spleen, intestine, lung, skin and uterus all have high levels of P100. P100 on peritoneal macrophages has been determined to be about 94 000 molecules/cell. Analyses of lung lavage and whole lung homogenates from mice treated with BHT, BHT plus 70% O 2, and 70% O 2 alone show that treated animals have elevated P100 content compared to corn oil treated mice.