Roles of reactive nitrogen intermediates and transforming growth factor-β produced by immunosuppressive macrophages in the expression of suppressor activity against T cell proliferation induced by TCR stimulation

Cytokine ◽  
2005 ◽  
Vol 30 (1) ◽  
pp. 7-13 ◽  
Author(s):  
Toshiaki Shimizu ◽  
Shanshan Cai ◽  
Haruaki Tomioka
2000 ◽  
Vol 68 (11) ◽  
pp. 6505-6508 ◽  
Author(s):  
K. A. Wilkinson ◽  
T. D. Martin ◽  
S. M. Reba ◽  
H. Aung ◽  
R. W. Redline ◽  
...  

ABSTRACT Latency-associated peptide of transforming growth factor β (TGF-β) (LAP) was used to determine whether in vivo modulation of TGF-β bioactivity enhanced pulmonary immunity to Mycobacterium bovis BCG infection in C57BL/6 mice. LAP decreased BCG growth in the lung and enhanced antigen-specific T-cell proliferation and gamma interferon mRNA expression. Thus, susceptibility of the lung to primary BCG infection may be partially mediated by the immunosuppressive effects of TGF-β.


2003 ◽  
Vol 23 (15) ◽  
pp. 5446-5459 ◽  
Author(s):  
S. Pearson-White ◽  
M. McDuffie

ABSTRACT The proto-oncogene Sno has been shown to be a negative regulator of transforming growth factor beta (TGF-β) signaling in vitro, using overexpression and artificial reporter systems. To examine Sno function in vivo, we made two targeted deletions at the Sno locus: a 5′ deletion, with reduced Sno protein (hypomorph), and an exon 1 deletion removing half the protein coding sequence, in which Sno protein is undetectable in homozygotes (null). Homozygous Sno hypomorph and null mutant mice are viable without gross developmental defects. We found that Sno mRNA is constitutively expressed in normal thymocytes and splenic T cells, with increased expression 1 h following T-cell receptor ligation. Although thymocyte and splenic T-cell populations appeared normal in mutant mice, T-cell proliferation in response to activating stimuli was defective in both mutant strains. This defect could be reversed by incubation with either anti-TGF-β antibodies or exogenous interleukin-2 (IL-2). Together, these findings suggest that Sno-dependent suppression of TGF-β signaling is required for upregulation of growth factor production and normal T-cell proliferation following receptor ligation. Indeed, both IL-2 and IL-4 levels are reduced in response to anti-CD3ε stimulation of mutant T cells, and transfected Sno activated an IL-2 reporter system in non-T cells. Mutant mouse embryo fibroblasts also exhibited a reduced cell proliferation rate that could be reversed by administration of anti-TGF-β. Our data provide strong evidence that Sno is a significant negative regulator of antiproliferative TGF-β signaling in both T cells and other cell types in vivo.


2012 ◽  
Vol 302 (1) ◽  
pp. L167-L173 ◽  
Author(s):  
Christine M. Deppong ◽  
Jian Xu ◽  
Steven L. Brody ◽  
Jonathan M. Green

Organ-specific regulation of immune responses relies on the exchange of information between nonimmune and immune cells. In a primary culture model of the lung airway, we demonstrate that T cell proliferation is potently inhibited by airway epithelial cells (ECs). This is mediated by activation of the IFNγ/STAT1 pathway in the EC and transforming growth factor-β (TGFβ)-dependent suppression of T cell proliferation. In this way, the EC can restrict the expansion of T cells. Given the constant exposure of the airway to inhaled antigen, this may be important in setting a threshold for the initiation of T cell-dependent immune responses and preventing unwanted, chronic inflammation.


Immunity ◽  
2009 ◽  
Vol 31 (1) ◽  
pp. 145-157 ◽  
Author(s):  
Roberto Tinoco ◽  
Victor Alcalde ◽  
Yating Yang ◽  
Karsten Sauer ◽  
Elina I. Zuniga

2016 ◽  
Vol 28 (12) ◽  
pp. 1873 ◽  
Author(s):  
Xiao-Feng Sun ◽  
Xing-Hong Sun ◽  
Shun-Feng Cheng ◽  
Jun-Jie Wang ◽  
Yan-Ni Feng ◽  
...  

The Notch and transforming growth factor (TGF)-β signalling pathways play an important role in granulosa cell proliferation. However, the mechanisms underlying the cross-talk between these two signalling pathways are unknown. Herein we demonstrated a functional synergism between Notch and TGF-β signalling in the regulation of preantral granulosa cell (PAGC) proliferation. Activation of TGF-β signalling increased hairy/enhancer-of-split related with YRPW motif 2 gene (Hey2) expression (one of the target genes of the Notch pathway) in PAGCs, and suppression of TGF-β signalling by Smad3 knockdown reduced Hey2 expression. Inhibition of the proliferation of PAGCs by N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycine t-butylester (DAPT), an inhibitor of Notch signalling, was rescued by both the addition of ActA and overexpression of Smad3, indicating an interaction between the TGF-β and Notch signalling pathways. Co-immunoprecipitation (CoIP) and chromatin immunoprecipitation (ChIP) assays were performed to identify the point of interaction between the two signalling pathways. CoIP showed direct protein–protein interaction between Smad3 and Notch2 intracellular domain (NICD2), whereas ChIP showed that Smad3 could be recruited to the promoter regions of Notch target genes as a transcription factor. Therefore, the findings of the present study support the idea that nuclear Smad3 protein can integrate with NICD2 to form a complex that acts as a transcription factor to bind specific DNA motifs in Notch target genes, such as Hey1 and Hey2, and thus participates in the transcriptional regulation of Notch target genes, as well as regulation of the proliferation of PAGCs.


Sign in / Sign up

Export Citation Format

Share Document