The Murine Cell Surface Antigen Pc-1 as a Marker for Plasma Cell

The murine plasma cell antigen PC-1 is a cell surface glycoprotein which is disulfic-bond homodimer of Mr 115 kD. It is expressed in large amounts of neoplastic plasma cell and on the majority of haemolytic plaque-forming cells1. It is also found in non-lymphoid tissues.1'2 In this paper a report of detailed distribution of PC-1 in a variety of normal lymphoid tissues using radioiodinated JR-518 monoclonal anti-PC-1 antibody as a probe is given, followed by autoradiography. Because the number of plasma cells in normal condition is very small, mice infected withMesocestoides corti have been used. These M.corti infected mice have high levels of IgGI in their serum (Mitchell et al, 1977). Hence, it was expected that the number of plasma cells may also be increased. Most small lymphocytes are negative of weakly positive. Cells that had morphology of typical plasma cells were mosdy positive. The large immunoglobulm-containing cells found in peritoneum of M.corti infected mice were strongly positive for PC-1. These results show that PC-1 antigen is expressed on normal plasma cells, the normal counterpart of myeloma cells. Therefore it can be used as a plasma surface marker