Effect of lymphocytes on the production of granulomonopoietic enhancing factor by fully mature macrophages.
The granulomonopoietic enhancing factor (GM-EF) is a novel myelopoietic regulator produced by human monocyte-derived lipid-containing macrophages (MDLMs). In the present study, we examined the effect of lymphocytes on GM-EF production by preincubation of MDLMs with various preparations of lymphocyte subpopulations in cell-mixed and in double agar layer cultures. Our results showed that a cell concentration-dependent suppression of GM-EF production was noted in cultures with mitogen-activated T cells, and mitogen-activated/resting B cells, while those containing resting T cells had no such effect. Thus, GM-EF production in the presence of 1 x 10(5)/ml activated T cells or activated/resting B cells was greatly reduced to 5% or 20%, respectively. The lymphocyte-induced suppression was evident in both cell-mixed and double layer cultures, implying that the effector cells might exert their influences via mediators. Assay for cytokine activity revealed that a high level (648.2-685.2 pg/ml) of tumor necrosis factor-alpha (TNF-alpha) was found in MDLM cultures with resting/activated B cells, and in those with activated T cells high levels of both TNF-alpha (510.5 pg/ml) and interferon-gamma (IFN-gamma) (321.3 pg/ml) could be detected, whereas in cultures with MDLMs and/or resting T cells, these cytokines were not measurable. Treatment of MDLMs with either recombinant (r) TNF-alpha or rIFN-gamma invariably resulted in a dose-dependent decrease in GM-EF production with intense suppression at doses between 400-800 U/ml.(ABSTRACT TRUNCATED AT 250 WORDS)
Wang
S Y
SY
Department of Medical Research, Veterans General Hospital-Taipei, Taiwan, Republic of China.
Chen
L Y
LY
Hsu
M L
ML
Tzeng
C H
CH
Ho
C H
CH
Ho
C K
CK
D001402:B-Lymphocytes / Q000276:immunology / Q000378:metabolism; D002450:Cell Communication; D002454:Cell Differentiation; D002478:Cells, Cultured; D006133:Growth Substances / Q000096:biosynthesis*; D006801:Humans; D007371:Interferon-gamma / Q000378:metabolism / Q000494:pharmacology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000276:immunology / Q000378:metabolism*; D008264:Macrophages / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011506:Proteins; D011994:Recombinant Proteins; D013601:T-Lymphocytes / Q000276:immunology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism / Q000494:pharmacology
D006133:Growth Substances; D011506:Proteins; D011994:Recombinant Proteins; D014409:Tumor Necrosis Factor-alpha; C057957:granulomonopoietic enhancing activity; D007371:Interferon-gamma