Gamma/delta receptor-expressing T-cell clones from a cutaneous T-cell lymphoma suppress hematopoiesis.
Recently we described a cutaneous T-cell lymphoma expressing the gamma/delta T-cell receptor [5]. The patient suffering from this lymphoma showed low numbers of myeloid and T cells in peripheral blood, while B and NK cells were relatively increased. In vitro culture of the patient's bone marrow (BM) cells revealed a significant suppression of myeloid/monocyte colony formation (GM-CFU) compared with normal controls. This was not due to infiltration of the BM with lymphoma cells. We speculated that a soluble factor either secreted or induced by the lymphoma cells might be responsible for the marked suppression of hematopoiesis in this patient. From a skin biopsy with infiltrating gamma/delta T-lymphoma cells we established T-cell clones bearing the gamma/delta T-cell receptor and resembling the phenotype of the lymphoma cells. The supernatant (SN) of these gamma/delta T-cell clones reduced the number of colonies in a CFU-GM assay (using normal control BM) in comparison to SN of alpha/beta T-cell clones established from the same biopsy. This suppression was seen mainly on day 7 of culture and was not neutralized by the addition of placenta-CM. The main mediator of this suppression seems to be IFN-gamma, since it was detectable in high amounts in the SN of these gamma/delta T-cell tumor clones as well as in the serum of the patient. In addition, anti-IFN-gamma antibodies can reverse the T-cell SN-mediated suppression of CFU-GM. We conclude that high serum levels of interferon-gamma, which is secreted in high amounts from gamma/delta T-cells grown from a biopsy of a cutaneous lymphoma, can suppress hematopoiesis.
Wilhelm
M
M
Medizinische Poliklinik, University of Würzburg, Federal Republic of Germany.
Meyer
P
P
Batram
C
C
Tony
H P
HP
Dummer
R
R
Nestle
F
F
Burg
G
G
Wilms
K
K
D001854:Bone Marrow Cells; D003114:Colony-Forming Units Assay; D006410:Hematopoiesis; D006801:Humans; D066298:In Vitro Techniques; D007371:Interferon-gamma / Q000502:physiology*; D016399:Lymphoma, T-Cell / Q000473:pathology*; D016692:Receptors, Antigen, T-Cell, gamma-delta / Q000378:metabolism*; D012878:Skin Neoplasms / Q000473:pathology; D014407:Tumor Cells, Cultured
D016692:Receptors, Antigen, T-Cell, gamma-delta; D007371:Interferon-gamma