Immunoregulation by blasts from null cell and T-cell leukemias: help and suppression of T-cell proliferative responses to mitogens.
The immunoregulatory activity of bone marrow leukemic blasts from five patients with null-cell acute lymphoblastic leukemia (ALL) and two children with T-cell ALL was evaluated. Blasts were studied in co-culture for their effects on the proliferative responses of normal allogeneic peripheral blood lymphocytes to phytohemagglutinin. Mitomycin C-treated null cell ALL blasts from two of five children suppressed the proliferative responses of normal responder cells by 80% and 58% whereas those from two other children enhanced the responses by 118% and 31%. T-cell leukemic blasts from one patient with T-cell ALL exhibited helper cell activity (26%) and T-leukemic blasts from the other demonstrated suppressor cell activity (53%). The helper cell activity of leukemic blasts was associated with stimulating capacity of null blasts in one-way mixed lymphocyte reactions. In six of seven cases, incubation of blast cells with concanavalin A (20 microgram/ml) for 48 hours prior to co-culture with responder cells did not result in the generation of significant suppressor cell activity. Our study suggests that leukemic blasts from certain patients with 'null' and T-cell ALL may possess spontaneous helper or suppressor cell immunoregulatory activity. This functional heterogeneity of leukemic blasts may help in subclassifying the ALL.
D000293:Adolescent; D001853:Bone Marrow / Q000187:drug effects; D002455:Cell Division; D002478:Cells, Cultured; D002648:Child; D002675:Child, Preschool; D003208:Concanavalin A / Q000494:pharmacology; D005260:Female; D006801:Humans; D007945:Leukemia, Lymphoid / Q000276:immunology*; D008215:Lymphocytes, Null / Q000187:drug effects* / Q000276:immunology; D008297:Male; D008934:Mitogens / Q000494:pharmacology*; D016685:Mitomycin; D008937:Mitomycins / Q000494:pharmacology; D010835:Phytohemagglutinins / Q000494:pharmacology; D013601:T-Lymphocytes / Q000187:drug effects* / Q000276:immunology; D050378:T-Lymphocytes, Regulatory / Q000187:drug effects / Q000276:immunology
D008934:Mitogens; D008937:Mitomycins; D010835:Phytohemagglutinins; D003208:Concanavalin A; D016685:Mitomycin