Mononuclear cells from infants allergic to cow's milk secrete tumor necrosis factor alpha, altering intestinal function.
OBJECTIVE
Intestinal dysfunction observed during cow's milk allergy (CMA) is incompletely understood, and neither the effector cells nor the mediators responsible have been clearly identified. This study was undertaken to better characterize the implication of mononuclear cells in food allergy.


METHODS
Peripheral blood mononuclear cells (PBMC) from infants with CMA were cultured in the presence of cow's milk proteins (CMP), and the release of tumor necrosis factor alpha (TNF-alpha), interferon gamma (IFN-gamma), and interleukin 4 and 6 was measured. The effect of culture supernatants was tested on HT29 cl.19A intestinal cell monolayers mounted in Ussing chambers.


RESULTS
When stimulated by CMP, PBMC from infants with CMA released more TNF-alpha than those from control infants (429 +/- 92 vs. 205 +/- 34 pg/mL). Culture supernatants did not directly stimulate electrogenic chloride secretion by HT29 cl.19A cells, but epithelial barrier capacity was altered as shown by the significant decrease in electrical resistance (85 +/- 17 vs. 135 +/- 14 omega.cm2 in controls) and the increases in intact horseradish peroxidase, [14C]mannitol, and 22Na+ fluxes. These effects were reversed when culture supernatants were neutralized with anti-TNF-alpha antibodies. Recombinant human-TNF-alpha altered the HT29 cl.19A epithelial barrier capacity, and its effect was highly potentiated by IFN-gamma.


CONCLUSIONS
These results indicate that during CMA, the high level of TNF-alpha released by mononuclear cells after milk protein challenge acts synergistically with IFN-gamma to increase the intestinal permeability.
Heyman
M
M
Institut National de la Santé et de la Recherche Médicale U290 Hôpital St Lazare, Paris, France.
Darmon
N
N
Dupont
C
C
Dugas
B
B
Hirribaren
A
A
Blaton
M A
MA
Desjeux
J F
JF
D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006735:Horseradish Peroxidase / Q000493:pharmacokinetics; D006801:Humans; D007223:Infant; D007422:Intestines / Q000473:pathology / Q000503:physiopathology*; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008213:Lymphocyte Activation; D008297:Male; D008353:Mannitol / Q000493:pharmacokinetics; D016269:Milk Hypersensitivity / Q000378:metabolism* / Q000503:physiopathology*; D008894:Milk Proteins / Q000494:pharmacology; D009000:Monocytes / Q000187:drug effects / Q000378:metabolism*; D010539:Permeability; D012964:Sodium / Q000493:pharmacokinetics; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism*
D016207:Cytokines; D008894:Milk Proteins; D014409:Tumor Necrosis Factor-alpha; D008353:Mannitol; D012964:Sodium; D007770:L-Lactate Dehydrogenase; D006735:Horseradish Peroxidase