Purification and characterization of human macrophage-derived granulomonopoietic enhancing factor (GM-EF).
A granulomonopoietic enhancing factor (GM-EF) capable of promoting the effect of colony-stimulating factors (CSFs) on myeloid progenitor cells has been purified to homogeneity from serum-free medium conditioned by fully mature human macrophages. GM-EF was a glycoprotein with an apparent molecular weight of 74 kd and an isoelectric point of 5.2-5.3. The purified protein was heat stable (75 degrees C for 30 min) and was sensitive to treatment with trypsin, papain, and bacterial protease but not to neuraminidase. The activity of GM-EF could be effectively neutralized by GM-EF-specific antiserum, and no antigenic cross-reactivity was observed using antisera against interleukin (IL)-1, IL-4, and IL-6. These results suggest that GM-EF is a unique cytokine that is different biochemically and antigenically from other hematopoietic enhancing factors such as IL-1, IL-4, and IL-6.
Wang
S Y
SY
Department of Medical Research, Veterans General Hospital-Taipei, Taiwan, Republic of China.
Wang
R C
RC
Chen
L Y
LY
Lieu
C W
CW
Su
S N
SN
Yung
C H
CH
Ho
C K
CK
D000939:Epitopes; D006133:Growth Substances / Q000737:chemistry / Q000276:immunology / Q000302:isolation & purification*; D006801:Humans; D007375:Interleukin-1 / Q000032:analysis / Q000276:immunology; D015847:Interleukin-4 / Q000032:analysis / Q000276:immunology; D015850:Interleukin-6 / Q000032:analysis / Q000276:immunology; D007525:Isoelectric Focusing; D008264:Macrophages / Q000378:metabolism*; D009500:Neutralization Tests; D011506:Proteins
D000939:Epitopes; D006133:Growth Substances; D007375:Interleukin-1; D015850:Interleukin-6; D011506:Proteins; C057957:granulomonopoietic enhancing activity; D015847:Interleukin-4