ALBUMIN-LIKE ANTIGEN IN THE HUMAN STABLE CELL-LINES

The 67-69 kD antigen (Ag) common to human stable cell lines and stomach mucosa (HSM), and serum albumin (HSA) have been studied for their immunological cross-reactivity. In the immunodiffusion test the antigen of both HEp-2 and E16-B cells performed a line of identity in the reaction with rabbit anti-HSA-serum. Rabbit antiserum against HSM components specifically reacted in the immunoblotting both with Ag 67 kD in the HSM and with the purified HSA. Ag 67 kD was revealed in the extracts of 4/7 cell lines tested so far; however, in E16-B and HEp-2 cell extracts it was detected using mouse anti-G-1 serum (against an antigen of normal HSM), as well as using rabbit and mouse antisera against HSA, meanwhile in the CaOV and Raji cell extracts Ag 67 kD could be revealed with the help of murine anti-HSA serum only. Murine anti-G-1 serum and murine anti-HSA serum also revealed Ag 67 kD in the HSM; moreover, in immunoblotting anti-G-1 serum reacted equally with it and with HSA. The reactions described were not related to the possible contamination with trypsin and/or bovine serum. Ag 67 kD was not related to alpha-fetoprotein.