Differential expression of surface proteins, virus receptors and histocompatibility antigens in SV40-transformed human choroid cells and their clones.

Human choroid (HC) cells transformed by Simian virus 40 (HC/SV40) and some of their soft agar-derived clones were utilized to study the influence of SV40 transformation on the expression of some differentiation parameters. The presence of receptors for DNA and RNA viruses, known to induce cytopathic effects in target cells, always occurred in normal HF and HC/SV40 cells as well as in their derived clones, whereas differences were observed in the expression of influenza A and Sindbis virus receptors. Immunofluorescence assays showed an increase in the expression of class I (HLA-A/B/C) and class II (DR) histocompatibility antigens in hyperdiploid clones compared with both the hypodiploid clones and the normal human cell counterpart. The two surface glycoproteins, fibronectin and laminin, appear only partially correlated with the transformed phenotype of the cells both at optical (immunofluorescence) and supraoptical (immunoelectron microscopy) level. This study confirms the SV40 transformation induces in human choroid cells a modulation of the considered differentiation parameters and that this may be due to a different insertion mode of the SV40 genome in HC cells.