Heterogenous expression of antigenic markers on retinoblasts

Using a large panel of monoclonal antibodies to antigenic determinants specific for photoreceptor outer segments (S-Ag), for cells of neural (Leu-7) bipolar and/or ganglion cell (A2B5), glial/astrocytic (LN-1) or Muller's cell (M.M.) and two polyclonal antibodies to S-Ag and S-100 protein, the authors studied the expression of these antigenic determinants in four newly established retinoblastoma cell cultures and in cells derived from the Y-79 cell line. All four newly established retinoblastoma cell cultures demonstrated antigenic determinants specific for photoreceptors, astrocyte/glial and Muller's cells. The population of cells derived from the Y-79 cell line reacted mainly with the polyclonal antibody to S-100 protein, reflecting the homogeneity of its cell population mainly harboring antigenic determinants specific for astrocyte/glial cells. The heterogeneic staining of the newly established retinoblastoma cell cultures may reflect the multipotential-embryonic origin of these cells demonstrated by their ability to express antigenic determinants specific for the different cellular elements of the mature neuro-retina while the strictly glial staining of the Y-79 may be the result of cloning of this cell line.