Monoclonal antibody analysis of Listeria monocytogenes-induced cytotoxic lymphocytes

An immunizing infection with Listeria monocytogenes provides a potent stimulus for the formation of prekiller lymphocytes. Their cytolytic potential is revealed when the cells are restimulated in vitro by Listeria antigens. Listeria monocytogenes-induced cytotoxic lymphocytes and the prekiller cells from which they are derived were characterized in respect to their surface antigenic markers. Using monoclonal antibodies, B-cell depleted lymphocytes from the thoracic duct of Listeria immune rats were fractionated into subsets by a combination of panning and sorting techniques. Listeria monocytogenes-induced cytotoxic lymphocytes and their prekiller cell precursors were demonstrated to have the phenotype W3/25-, OX8+, OX4+, W3/13+ (high density), OX19+ (low density), RT6.1-. The OX8+, RT6.1- subset, which contained prekiller cells, constituted approximately 6% of lymph-borne T cells. The data indicate that these microbial antigen-induced cytotoxic lymphocytes belong to a minor subset of peripheral T cells whose surface antigenic properties distinguish them from natural killer cells.