A soluble factor released by CD8+CD57+ lymphocytes from bone marrow transplanted patients inhibits cell-mediated cytolysis

Abstract

We report a new inhibitory activity of CD8 CD57 peripheral Mood lymphocytes from allo-bone marrow transplant patients. Positively selected CD8+CD57+ lymphocytes act as potent inhibitors of allospecific cytolytic T lymphocyte and lyrnphokine activated killer cell cytolytic activities. These suppressor cells are mature T cells expressing the CD2, 5, 7, CD3-TcRαβ complex, and lack natural killer cell markers as well as cytolytic function. Their inhibitory activity on both cytolytic processes and T-cell proliferation is mediated by a non-antigen-specific soluble factor released by CD8 CD57 cells in culture supernatants. Preliminary characterization suggests that the CDS CD57 cells' inhibitory activity is mediated by a low molecular weight, glycosylated factor as indicated by its less than IS coefficient of sedimentation and its binding to concanavalin A lectin. © 1991 by The American Society of Hematology.