Evidence for a paracrine pathway of B-cell stimulation in hairy cell leukaemia.
It is a well-known phenomenon that the growth of malignant B-lymphocytes, i.e. hairy cells, is regulated by cytokines. Several investigators have suggested that the stimulating cytokines are produced by the malignant B cells themselves, indicating an autocrine growth regulation. In this paper we demonstrate that T-lymphocyte clones produce soluble mediators which stimulate the growth of malignant B lymphocytes. The incidence of the growth-stimulating T-cell clones derived from peripheral blood is identical in patients with hairy cell leukaemia (HCL) and healthy controls. About 50% of the clones stimulate the growth of hairy cells, but not the growth of purified B lymphocytes of healthy donors. The stimulating activity of a single clone varies when tested on different hairy cells. Interferon alpha (IFN alpha), but not antibodies against tumour necrosis factor alpha (TNF alpha) or interleukin-2 (IL-2), completely inhibit the growth-stimulating activity. Our results indicate that a paracrine growth regulation has to be considered in addition to the postulated autocrine loop in the growth regulation of malignant B cells.
Schmid
M
M
Department of Medicine III (Haematology and Oncology), University of Ulm, Germany.
Schrezenmeier
H
H
Staib
G
G
Porzsolt
F
F
D001402:B-Lymphocytes / Q000276:immunology*; D001483:Base Sequence; D002455:Cell Division / Q000276:immunology; D002478:Cells, Cultured; D006801:Humans; D007370:Interferon Type I / Q000276:immunology; D007376:Interleukin-2 / Q000276:immunology; D007943:Leukemia, Hairy Cell / Q000276:immunology*; D008213:Lymphocyte Activation / Q000276:immunology*; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011994:Recombinant Proteins; D013601:T-Lymphocytes / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology
D007370:Interferon Type I; D007376:Interleukin-2; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha