High cytosolic pool of p75 TNF receptors and delayed surface downmodulation by mononuclear cells from non-hodgkin's lymphoma patients.
Analysis of the expression of TNF-Rs on fresh peripheral blood mononuclear cells (PBMNC) by Scatchard analysis showed that Gr I (stages I and II) but not Gr II (stages III and IV) NHL patients have a significantly higher expression of surface TNF-Rs than normal controls. A rapid decrease in the binding of radiolabelled anti-p75 TNF-R Mab which gradually increased after 16 h was seen in normal controls, while NHL patients showed a rapid increase in the binding of the Mab after activation of cells and a decrease in binding was observed only after 24 h. Western blot analysis for normal controls showed a weak presence of the 42 kDa fragment only, while the cytosolic extracts from fresh PBMNCs of NHL patients showed presence of both intact p75 TNF-R, as well as a 42 kDa fragment corresponding to a soluble form of p75 TNF-R. Our results suggest that increased cytosolic pools of TNF-R in NHL patients might contribute to a rapid increase in its surface expression following activation of cells.
Rathore
V B
VB
Immunology Division, Tata Memorial Centre, India.
Advani
S H
SH
Nadkarni
J J
JJ
D000328:Adult; D000368:Aged; D015703:Antigens, CD / Q000378:metabolism*; D015153:Blotting, Western; D002478:Cells, Cultured; D003600:Cytosol / Q000378:metabolism; D015536:Down-Regulation; D005260:Female; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D008228:Lymphoma, Non-Hodgkin / Q000097:blood / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D011485:Protein Binding; D018124:Receptors, Tumor Necrosis Factor / Q000378:metabolism*; D047889:Receptors, Tumor Necrosis Factor, Type II; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology
D015703:Antigens, CD; D018124:Receptors, Tumor Necrosis Factor; D047889:Receptors, Tumor Necrosis Factor, Type II; D013755:Tetradecanoylphorbol Acetate