The effect of recombinant TGFalpha, human milk, and human milk macrophage media on gut epithelial proliferation is decreased in the presence of a neutralizing TGFalpha antibody.
OBJECTIVE
An in vitro model was devised to compare the relative effects of recombinant transforming growth factor-alpha (TGFalpha), aqueous human milk, and human milk macrophage (HMM) medium on human fetal small intestinal cell (FHs-74) proliferation.


METHODS
Recombinant TGFalpha at increasing concentrations (range 0.01-1,000 ng/ml media), the aqueous fraction of human milk (AHM), or HMM medium was added to FHs-74 cells in the presence or absence of a neutralizing TGFalpha antibody (1 microgram/ml medium). At 24 h, cell proliferation was measured and expressed as percent control. The experimental variables were (1) activators of cell growth (TGFalpha, AHM, and HMM medium); (2) increasing concentrations of TGFalpha, and (3) neutralizing antibody to TGFalpha. The dependent variable for all experiments was cell proliferation.


RESULTS
Significant effects for growth stimulators and TGFalpha concentration as measured by cell proliferation were found. Specifically, there was a dose-dependent effect of TGFalpha on cell proliferation to the 5-ng/ml concentration, with a plateau reached in cell proliferation at higher concentrations. The stimulatory effect of TGFalpha was decreased in the presence of TGFalpha antibody (mean +/- SD 22 +/- 7. 1% decline, p < 0.001). In the presence of TGFalpha antibody, there was a 25 +/- 3.1% decline in HM-stimulated growth (p < 0.004), and a 27.6 +/- 3.2% decline in HMM medium-stimulated growth (p < 0.001).


CONCLUSIONS
Neutralization of recombinant TGFalpha and that present in human milk and HMM medium by TGFalpha antibody led to a consistent decrease in in vitro human fetal small intestine epithelial proliferation without affecting cell viability. These results support the hypothesis that TGFalpha, whether derived from human recombinant sources, human milk or HMM medium has a measurable, trophic effect on in vitro human gut epithelial cells.
Wagner
C L
CL
Department of Pediatrics, Human Milk Lactation Research and Education Center, Children's Hospital, Medical University of South Carolina, Charleston, S.C., USA. wagnercl@musc.edu
Forsythe
D W
DW
Wagner
M T
MT
D000818:Animals; D000906:Antibodies / Q000494:pharmacology*; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D003470:Culture Media / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D006801:Humans; D007413:Intestinal Mucosa / Q000166:cytology* / Q000187:drug effects / Q000196:embryology; D007421:Intestine, Small / Q000166:cytology / Q000187:drug effects / Q000196:embryology; D008264:Macrophages / Q000378:metabolism*; D008892:Milk / Q000166:cytology / Q000502:physiology*; D011994:Recombinant Proteins; D016211:Transforming Growth Factor alpha / Q000276:immunology / Q000494:pharmacology*
D000906:Antibodies; D003470:Culture Media; D011994:Recombinant Proteins; D016211:Transforming Growth Factor alpha