Skip to main page content
U.S. flag
See More

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2002 Sep;161(3):771-9.
doi: 10.1016/s0002-9440(10)64236-8.

Enteric expression of the integrin alpha(v)beta(6) is essential for nematode-induced mucosal mast cell hyperplasia and expression of the granule chymase, mouse mast cell protease-1

Pamela A Knight  1 , Steven H Wright, Jeremy K Brown, Xiaozhu Huang, Dean Sheppard, Hugh R P Miller
Affiliations

Enteric expression of the integrin alpha(v)beta(6) is essential for nematode-induced mucosal mast cell hyperplasia and expression of the granule chymase, mouse mast cell protease-1

Pamela A Knight et al. Am J Pathol. 2002 Sep.

Abstract

The immunoregulatory cytokine transforming growth factor (TGF)-beta(1) is secreted as a biologically inactive complex with latency-associated peptide, which must be modified by local factors to expose the functionally active cytokine. The epithelial integrin alpha(v)beta(6) mediates local activation of TGF-beta(1) in the lung and beta(6)(-/-) mice exhibit exaggerated pulmonary inflammation, but their response to inflammatory stimuli in the gut has not been investigated. We found that both beta(6) and TGF-beta(1) are constitutively expressed in the jejunal epithelial compartment in uninfected mice and during infection with the intestinal nematode Nippostrongylus brasiliensis. We also present data showing that beta(6)(-/-) mice are seriously compromised in their ability to mount a mucosal mast cell response after infection, and there is a significant reduction in the expression and systemic release of the granule chymase, mouse mast cell protease-1. Because in vitro expression of this chymase is regulated by TGF-beta(1), these data indicate that in the absence of alpha(v)beta(6) epithelially expressed TGF-beta(1) may not be activated, with a consequent absence of expression of mouse mast cell protease-1 and down-regulation of the mucosal mast cell response.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
a: H&E-stained exfoliated jejunal epithelium from S129 mice, showing the relative absence of contaminating cells from the lamina propria (horizontal bar, 20 μm). b and c: Sections of jejunum from an S129 mouse taken on day 7 after infection with N. brasiliensis, stained with rabbit anti-integrin β6 IgG B1, specific for integrin β6 (b) or normal rabbit control IgG (c) (horizontal bar, 10 μm). Note the predominantly circumferential immunofluorescence in the crypt epithelium. Confocal images were acquired in fast photon-counting mode (300 accumulated frames) and have not been subjected to contrast enhancement of any form. d: RT-PCR products for TGF-β1 (405 bp), integrin β6 (340 bp), IgA (316 bp), and the housekeeping gene GAPDH (430 bp) from total RNA extracted from whole jejunum on day 7 after challenge with N. brasiliensis (WJ), and from isolated epithelium taken on day 0 (0-1 to 0-3), day 5 (5-1 to 5-3), day 7 (7-1 to 7-3), and day 9 (9-1 to 9-3) after infection with N. brasiliensis and a negative control with nonreverse-transcribed RNA only (c). Note that transcripts for β6 are apparently less abundant in whole jejunum than in isolated epithelium and that, conversely, the intensity of RT-PCR signals for TGF-β1 and for IgA are stronger in samples of whole jejunum (WJ) with little or no signal for IgA in isolated epithelium. e: Relative abundance of mast cell protease transcripts in isolated epithelium from S129 mice. The graphs show the intensity of each PCR product as a proportion of corresponding GAPDH product from the same sample. Data are shown from samples taken on day 0 (uninfected) (open columns), day 5 (horizontally lined columns), day 7 (hexagonally lined columns), and day 9 (filled columns) after infection with N. brasiliensis. Primers were for mMCP-1 (M1) and mMCP-2 (M2). (dOvsd9: ∗p < 0.05, ∗∗p < 0.01).
Figure 2.
Figure 2.
a: Mucosal mast cells quantified per villus/crypt unit (vcu) (±SE) in the jejunum from β6+/+ (filled columns) and β6−/− (open columns) S129 mice on day 0 (uninfected), and days 5, 7, and 9 after N. brasiliensis infection. b: Mast cells (±SE) per mm2 in the stomach (glandular region) from β6+/+ and β6−/− S129 mice on day 0 (uninfected), and days 5, 7, and 9 after N. brasiliensis infection. (β6+/+ vs. β6−/−; ∗p < 0.05, ∗∗p < 0.01). c and d: Toluidine blue/eosin-stained jejunum from β6+/+ (c) and β6−/− (d) S129 mice 9 days after infection with N. brasiliensis (horizontal bar, 50 μm). Arrows indicate the presence of toluidine blue-stained MMCs.
Figure 3.
Figure 3.
a and b: Concentrations of mMCP-1 in serum (μg/ml) (a) and jejunal homogenates (μg/g wet wt) (b) from β6+/+ (filled columns) and β6−/− (open columns) S129 mice on day 0 (uninfected), and days 5, 7, and 9 after infection. c: Abundance of protease gene transcripts in jejunal RNA. The data shows the intensity of each PCR product as a proportion of the corresponding GAPDH product from the same sample. Data are shown from samples taken from β6+/+ and β6−/− 129 mice on days 0 and 9 after infection with N. brasiliensis as indicated. Primers were for mMCP-1 (M1) and mMCP-2 (M2) as indicated. d: mMCP-1+ve MMC counts (±SE) in the jejunum from β6+/+ and β6−/− S129 mice on day 0 (uninfected), and days 5, 7, and 9 after N. brasiliensis infection after staining with mAb RF6.1. Cell counts are shown per villus/crypt unit (vcu). (β6+/+ vs. β6−/−: ∗p < 0.05, ∗∗p < 0.01).
See this image and copyright information in PMC

References

    1. Lee CG, Homer RJ, Zhu Z, Lanone S, Wang X, Koteliansky V, Shipley JM, Gotwals P, Noble P, Chen Q, Senior RM, Elias JA: Interleukin-13 induces tissue fibrosis by selectively stimulating and activating transforming growth factor beta (1). J Exp Med 2001, 194:809-822 - PMC - PubMed
    1. Podolsky DK: Healing the epithelium: solving the problem from two sides. J Gastroenterol 1997, 32:122-126 - PubMed
    1. MacDonald TT: Effector and regulatory lymphoid cells and cytokines in mucosal sites. Curr Top Microbiol Immunol 1999, 236:113-135 - PubMed
    1. Yang X, Letterio JJ, Lechleider RJ, Chen L, Hayman R, Gu H, Roberts AB, Deng C: Targeted disruption of SMAD3 results in impaired mucosal immunity and diminished T cell responsiveness to TGF-beta. EMBO J 1999, 18:1280-1291 - PMC - PubMed
    1. Roche JK, Martins CA, Cosme R, Fayer R, Guerrant RL: Transforming growth factor beta1 ameliorates intestinal epithelial barrier disruption by Cryptosporidium parvum in vitro in the absence of mucosal T lymphocytes. Infect Immun 2000, 68:5635-5644 - PMC - PubMed

Publication types

MeSH terms

LinkOut - more resources