NOVEL FIBROBLAST SPECIFIC MONOCLONAL-ANTIBODIES - PROPERTIES AND SPECIFICITIES

Specific detection of fibroblasts has been one of the unsolved problem s in cell biology, Because monoclonal antibodies (MoAbs) might provide an easy and reproducible method of fibroblast detection, we have prod uced a panel of MoAbs raised against cell surface proteins of human de rmal fibroblasts. Using flow cytometry and immunohistochemistry, we ha ve shown that two of these MoAbs. FibAS01 and FibAS02, react exclusive ly with human fibroblasts. They do not react in vitro with human kerat inocytes, endothelial cells, or blood cells, Immunohistologic experime nts investigating the binding pattern of the MoAbs FibAS01 and FibAS02 in cryostat sections of different tissues confirmed the flow cytometr ic results, In human skin, the antibodies exclusively labeled fibrobla sts. In other human tissues such as lymph nodes, placenta, kidney, mus cle, thyroid gland, gall bladder, cartilage, and tendon, the specifici ty for fibroblasts was borne out, Neither antibody reacts with fibrobl asts from mouse, rat, or pig, The isotype was defined as an IgG1 for b oth. By western blot analysis, both antibodies detected a molecule of 60-65 kDa under reducing and nonreducing conditions, By immunoelectron microscopy, we observed the antigens on the cell surface without any clustering at specific sites, These data demonstrate that the two MoAb s, FibAS01 and FibAS02, exclusively recognize human fibroblasts.