NEURONAL INTERFERON-GAMMA IMMUNOREACTIVE MOLECULE - BIOACTIVITIES ANDPURIFICATION

An interferon (IFN)-gamma immunoreactive molecule, localized to small neurons in peripheral sensory ganglia (N-IFN-gamma), has been detected with two mouse monoclonal antibodies (DB1 and DB16) directed against different epitopes of rat IFN-gamma. To define N-IFN-gamma with regard to its protein characteristics and bioactivities. DB1 and DB16 were u sed to purify N-IFN-gamma, from rat trigeminal ganglia in a two-step s equential antibody-affinity procedure. Sodium dodecylsulfate polyacryl amide gel electrophoresis (PAGE) and silver staining of purified N-IFN -gamma displayed three bands with an approximate molecular mass of 66, 62 and 54 kDa. The N-IFN-gamma, bioactivity was confined to the prote in stained on gel when native material was run on PAGE, Biological eff ects of pure N-IFN-gamma were examined and compared with those of lymp hocyte-derived recombinant IFN-gamma. N-IFN-gamma had antiviral effect s in vitro and induced major histocompatibility complex class I and II antigens on macrophages and in cells in skeletal muscle cell cultures . N-IFN-gamma also stimulated myoblast proliferation and affected chol inergic receptor distribution on myotubes similar to recombinant IFN-g amma. Both molecules potently stimulated Trypanosoma brucei brucei gro wth. These data suggest that, although N-IFN-gamma, is a protein disti nct from lymphocyte-derived IFN-gamma, the two molecules have enough s tructural similarities to allow for antibody recognition of at least t wo epitopes, and action on similar target structures on both parasite and mammalian cells.