Polyclonal antibody localizes glia maturation factor beta-like immunoreactivity in neurons and glia

A rabbit polyclonal antibody (91-01) was raised against recombinant human glia maturation factor beta (r-hGMF-beta). The antibody did not cross-react with a number of other growth factors on ELISA test. When compared with the monoclonal antibody G2-09 previously obtained, 91-01 immunoblotted the same protein band in rat brain extract. However, unlike G2-09 which immunostained only astrocytes and Bergmann glia, 91-01 stained neurons as well. Many but not all neurons in the central and peripheral nervous system were positive for GMF-beta. The larger cell population stained by the polyclonal antibody was most likely due to its increased sensitivity, although other explanations are possible. The presence of GMF-beta-like immunoreactivity in both neurons and glia raises the possibility of a wider range of cell-cell interaction than was previously considered.