Tumor necrosis factor-alpha in human milk.
We previously demonstrated that certain biologic activities in human milk were partially blocked by antibodies directed against human tumor necrosis factor-alpha (TNF-alpha). In this study, immunochemical methods were used to verify the presence of TNF-alpha in human milk obtained during the first few days of lactation. Gel filtration revealed the presence of TNF-alpha by RIA in molecular weight fractions between 80 and 195 kD. TNF-alpha could not be detected consistently by conventional Western blotting or cytotoxic assays. Although immunoreactive bands were detected by a Western blot-125I protein A technique in TNF-alpha-positive fractions from gel filtration, those bands proved to be nonspecific. TNF-alpha in milk was reliably quantified by the competitive RIA. Those studies revealed that the concentrations of TNF-alpha in milk were 620 +/- 183 pg/mL. Although RNA to TNF-alpha was detected in milk leukocytes by Northern blotting, little TNF-alpha was found in those cells before or after stimulation with N-formyl-l-methionyl-l-leucyl-l-phenylalanine or 4 beta-phorbol-12 beta-myristate-13 alpha-acetate. The origin of this cytokine in human milk remains unclear. Nevertheless, this study suggests that TNF-alpha is present in early human milk in sufficient quantities to exert possible biologic effects upon the mammary gland of the mother or the immune system of the infant.
Rudloff
H E
HE
Department of Pediatrics, University of Texas Medical Branch, Galveston 77555.
Schmalstieg
F C
FC
Mushtaha
A A
AA
Palkowetz
K H
KH
Liu
S K
SK
Goldman
A S
AS
D000293:Adolescent; D000328:Adult; D002850:Chromatography, Gel; D005260:Female; D006801:Humans; D007962:Leukocytes / Q000276:immunology; D008894:Milk Proteins / Q000276:immunology; D008895:Milk, Human / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D008970:Molecular Weight; D011247:Pregnancy; D012313:RNA / Q000378:metabolism; D011863:Radioimmunoassay; D014409:Tumor Necrosis Factor-alpha / Q000302:isolation & purification*
D008894:Milk Proteins; D014409:Tumor Necrosis Factor-alpha; D012313:RNA