AMLR-reactive T cells isolated by autologous rosette formation

Abstract

Peripheral blood lymphocytes capable of binding autologous erythrocytes in vitro (A-RFC) have been characterized and tested for their capacity to respond in autologous and allogeneic mixed-lymphocyte reactions. The incidence of human A-RFC ranged from 0 to 18%, however, several variables were found to increase the detectable percentage to 40–60%, these being the presence of serum in the assay mixture and pretreatment of erythrocytes with neuraminidase. No significant differences were detected when comparing allogeneic to autologous erythrocytes in the formation of rosettes, indicating a lack of MHC restriction of the phenomenon. Human A-RFC were surface immunoglobulin-negative, complement receptor-negative, nonphagocytic α-napthylacetate esterase-positive cells, approximately 90% of which were small lymphocytes exhibiting a punctate staining reaction. Remaining A-RFC exhibited a diffuse staining reaction and were morphologically identified as large granular lymphocytes (LGL). One hundred percent of A-RFC corosetted sheep and autologous human erythrocytes and stained positive with Leu-1 monoclonal anti T-cell antibody. Approximately 16% of A-RFC expressed receptors for IgG and an average of 66% expressed receptors for IgM after overnight culture. The ability of A-RFC enriched and depleted T-cell subpopulation to respond to stimulation with autologous and unrelated allogeneic non-T lymphoid cell populations was also examined. We found that A-RFC-enriched populations responded vigorously to autologous stimulation, but poorly to allogeneic stimuli. In contrast, A-RFC-depleted populations responded vigorously to allogeneic but poorly to autologous stimuli.