Continuous cytotoxic T cell lines reactive against murine plasmacytoma tumor-associated antigens

Abstract

Continuous cytotoxic T cell lines against murine tumor-associated antigens (TAA) were generated from normal BALB/c and (C57BL/6 X BALB/c)F1 spleen lymphocytes by sensitizing these cells in vitro to the BALB/c plasmacytoma (PCT) MPC-11. These cytotoxic T cell lines (CTLL) were maintained for periods of over 1 yr in T cell growth factor from cultures of mitogen-stimulated rat spleen cells. The lines were highly cytotoxic against the immunizing tumor, as well as against a select number of other tumor cell lines, and the patterns of reactivity of 3 of these lines against the various tumor cell targets indicated that these lines each recognized different PCT TAA. The antigens recognized included an MHC-restricted PCT antigen, an antigen shared by PCT and T lymphomas, and an MPC-11 unique PCT antigen. phenotypic characterization of the CTLL populations for cell surface marker expression indicated that they were largely homogeneous with respect to their differentiation state, and expressed Thy-1.2, Lyt-2, Lyt-3.2, and T30 antigens on their cell surface. In addition, 1 of the lines demonstrated variable low-level expression of Lyt-1. Thus, the populations were characteristics of mature T cells, and did not express cell surface markers characteristic of other lymphocyte subpopulations.