Role of cell-cell interactions in the developmental regulation of Ca2+-activated K+ currents in vertebrate neurons

1998 ◽  
Vol 37 (1) ◽  
pp. 23-36 ◽  
Author(s):  
Stuart E. Dryer
2000 ◽  
Vol 113 (3) ◽  
pp. 391-400 ◽  
Author(s):  
D.A. Bleijs ◽  
M.E. Binnerts ◽  
S.J. van Vliet ◽  
C.G. Figdor ◽  
Y. van Kooyk

Although ICAM-3 is implicated in both adhesion and signal transduction events of leukocytes, its low affinity for LFA-1 compared to other ligands of LFA-1 has puzzled many investigators. Here we investigated the role of ICAM-3 in supporting LFA-1-mediated ICAM-1 binding and subsequently cell signaling. We observed that although ICAM-3 binds poorly to LFA-1 expressed on resting T cells, it specifically facilitates and increases LFA-1-mediated adhesion to the high affinity ligand of LFA-1, ICAM-1. We demonstrate that low-affinity binding of LFA-1 to ICAM-3 together with ICAM-1 alters the cell surface distribution of LFA-1 dramatically, inducing large clusters of LFA-1 that facilitate ICAM-1 binding after LFA-1 activation. We found that LFA-1-mediated ICAM-1 cell-cell interactions such as T cell proliferation greatly depend on low affinity LFA-1/ICAM-3 interactions that enhance stable LFA-1/ICAM-1 cell-cell contact. Taken together, these data demonstrate that low affinity LFA-1 binding to ICAM-3 regulates strong LFA-1/ICAM-1-mediated adhesion by driving LFA-1 into clusters to facilitate cell-cell interactions that take place in the immune system.


2021 ◽  
Vol 12 ◽  
Author(s):  
Lucas H. Armitage ◽  
Scott E. Stimpson ◽  
Katherine E. Santostefano ◽  
Lina Sui ◽  
Similoluwa Ogundare ◽  
...  

Type 1 diabetes (T1D) is a disease that arises due to complex immunogenetic mechanisms. Key cell-cell interactions involved in the pathogenesis of T1D are activation of autoreactive T cells by dendritic cells (DC), migration of T cells across endothelial cells (EC) lining capillary walls into the islets of Langerhans, interaction of T cells with macrophages in the islets, and killing of β-cells by autoreactive CD8+ T cells. Overall, pathogenic cell-cell interactions are likely regulated by the individual’s collection of genetic T1D-risk variants. To accurately model the role of genetics, it is essential to build systems to interrogate single candidate genes in isolation during the interactions of cells that are essential for disease development. However, obtaining single-donor matched cells relevant to T1D is a challenge. Sourcing these genetic variants from human induced pluripotent stem cells (iPSC) avoids this limitation. Herein, we have differentiated iPSC from one donor into DC, macrophages, EC, and β-cells. Additionally, we also engineered T cell avatars from the same donor to provide an in vitro platform to study genetic influences on these critical cellular interactions. This proof of concept demonstrates the ability to derive an isogenic system from a single donor to study these relevant cell-cell interactions. Our system constitutes an interdisciplinary approach with a controlled environment that provides a proof-of-concept for future studies to determine the role of disease alleles (e.g. IFIH1, PTPN22, SH2B3, TYK2) in regulating cell-cell interactions and cell-specific contributions to the pathogenesis of T1D.


2013 ◽  
Vol 33 (16) ◽  
pp. 3077-3090 ◽  
Author(s):  
Katherine C. Hall ◽  
Daniel Hill ◽  
Miguel Otero ◽  
Darren A. Plumb ◽  
Dara Froemel ◽  
...  

Endochondral ossification is a highly regulated process that relies on properly orchestrated cell-cell interactions in the developing growth plate. This study is focused on understanding the role of a crucial regulator of cell-cell interactions, the membrane-anchored metalloproteinase ADAM17, in endochondral ossification. ADAM17 releases growth factors, cytokines, and other membrane proteins from cells and is essential for epidermal growth factor receptor (EGFR) signaling and for processing tumor necrosis factor alpha. Here, we report that mice lacking ADAM17 in chondrocytes (A17ΔCh) have a significantly expanded zone of hypertrophic chondrocytes in the growth plate and retarded growth of long bones. This abnormality is caused by an accumulation of the most terminally differentiated type of chondrocytes that produces a calcified matrix. Inactivation of ADAM17 in osteoclasts or endothelial cells does not affect the zone of hypertrophic chondrocytes, suggesting that the main role of ADAM17 in the growth plate is in chondrocytes. This notion is further supported byin vitroexperiments showing enhanced hypertrophic differentiation of primary chondrocytes lackingAdam17. The enlarged zone of hypertrophic chondrocytes inA17ΔChmice resembles that described in mice with mutant EGFR signaling or lack of its ligand transforming growth factor α (TGFα), suggesting that ADAM17 regulates terminal differentiation of chondrocytes during endochondral ossification by activating the TGFα/EGFR signaling axis.


Cell Systems ◽  
2018 ◽  
Vol 6 (4) ◽  
pp. 496-507.e6 ◽  
Author(s):  
Simon van Vliet ◽  
Alma Dal Co ◽  
Annina R. Winkler ◽  
Stefanie Spriewald ◽  
Bärbel Stecher ◽  
...  

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