[Internalization of tumor associated antigen on human lung adenocarcinoma cell line SPC-A-1 by McAb LC-1].

Antigenic modulation of tumor cells is a kind of immunophenomenon that the antigenicity of tumor cell surface antigen could be lessened, weakened or completely lost. It is a potential route for tumor cells to escape the immunosurveillance and immunoattack of the host. One of the means to cause the antigenic modulation is by means of the antibody. In present research, gold labeled monoclonal antibody LC-1, which is raised against human lung cancer in our lab, as a molecular tracer to study the internalization and the subsequent fate of the membrane tumor associated antigen-LC-1 complex on the SPC-A-1 cell surface has been used. We found that this complex was internalized via the receptor-mediated endocytic pathway and concentrated in the multivesicular bodies and transported to lysosomes for proteolysis in the end. Strikingly, we noted that LC-1 had induced the autophagocytosis of ribosomes in SPC-A-1 cells in the median time it induced the internalization of the cell surface antigen cause by internalization and the restoration after antigenic modulation were also analyzed by the fluorescence activated cell sorter (FACS).