Interleukin 2 (IL 2) and interferon-gamma production by T lymphocytes from patients with B-chronic lymphocytic leukemia: evidence that normally released IL 2 is absorbed by the neoplastic B cell population.
The capacity of T lymphocytes from patients with B cell chronic lymphocytic leukemia (B-CLL) to release interleukin 2 (IL 2) and interferon (IFN)-gamma was assessed following various stimuli. The spontaneous release of IL 2 and IFN-gamma was practically absent both with B-CLL and normal T lymphocytes. By contrast, after stimulation with phytohemagglutinin (PHA) or with PHA plus 12-O-tetradecanoylphorbol-13-acetate, the production of IL 2 and IFN-gamma by B-CLL T lymphocytes was similar to that of normal T lymphocytes, irrespective of the reversed T lymphocyte subset distribution (OKT4/OKT8 ratio) observed in B-CLL. However, the titer of IL 2 was greatly reduced when autologous leukemic B cells were added to the culture system. Unlike IL 2, the presence of leukemic B cells did not affect the titer of IFN-gamma in the culture supernatants. The indication that IL 2 may be adsorbed in vivo by the neoplastic B cells was further confirmed by the demonstration of the IL 2 receptor (revealed by anti-Tac monoclonal antibody) on the leukemic B cells, particularly following mitogenic stimulation, and by the evidence that exogenous IL 2 can be directly absorbed by untreated B-CLL T lymphocytes to release IFN-gamma and IL 2 is preserved, but that IL 2 may be rapidly removed by the neoplastic B-CLL cells, thus contributing to the well-documented T lymphocyte abnormalities present in this disease.
Foa
R
R
Giovarelli
M
M
Jemma
C
C
Fierro
M T
MT
Lusso
P
P
Ferrando
M L
ML
Lauria
F
F
Forni
G
G
D000042:Absorption; D000954:Antigens, Surface / Q000032:analysis; D001402:B-Lymphocytes / Q000145:classification / Q000378:metabolism* / Q000473:pathology; D002478:Cells, Cultured; D006801:Humans; D007371:Interferon-gamma / Q000096:biosynthesis*; D007376:Interleukin-2 / Q000096:biosynthesis*; D007945:Leukemia, Lymphoid / Q000097:blood* / Q000276:immunology; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D010641:Phenotype; D013601:T-Lymphocytes / Q000145:classification / Q000378:metabolism*; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7
D000954:Antigens, Surface; D007376:Interleukin-2; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D007371:Interferon-gamma