PRODUCTION OF ANTI-RGNTF ANTI-IDIOTYPIC ANTIBODY AND RECEPTOR IDENTIFICATION SPECIFIC FOR RGNTF / 解剖学报

ABSTRACT

By immunizing Balb/c mice with immunoglobulin IgG which was isolated from the D_3 monoclonal antibody specific to the retinal ganglion neuronotrophic factor (RGNTF-McAb) with a Phast System gel electrophoretic method, we have developed anti-idiotypic antibodies against the RGNTF-McAb. A MTT colorimetric microassay designed to measure the effect of conditioned media from hybridomas containing antibodies on the growth activities of retinoblastoma (Rb) cells, was used to screen for idiotypic antibodies from these hybridomas. The results showed that G_4 hybridoma produced an anti-idiotypic antibody which could bind to the D_3 RGNTF-McAb and neutralize the inhibitory function of D3 on Rb cells, and possessed the trophic activity similar to RGNTF in promoting the growth activity of Rb cells. Immunohistochemical studies with anti-idiotypic antibody revealed that Rb cells and embryonic and neonatal rat retinal ganglion cells possessed coarse immunoreactive positive granules distributed on their cell surface membrane. These granules are identified as the receptors for RGNTF. Therefore, we concluded that the G_4 monoclonal antibody is not only an anti-idiotypic antibody but also an anti-paratopic antibody, It may be very useful in studying the mechanism of action of RGNTF and has a widespread applications in future.