Format

Send to

Choose Destination
J Immunol. 2019 Nov 22. pii: ji1900680. doi: 10.4049/jimmunol.1900680. [Epub ahead of print]

Th1 Cells Rolling on Selectins Trigger DAP12-Dependent Signals That Activate Integrin αLβ2.

Author information

1
Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104; and.
2
Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104.
3
Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, Oklahoma City, OK 73104; and rodger-mcever@omrf.org.

Abstract

During inflammation, both neutrophils and effector T cells use selectins to roll and integrins to arrest in postcapillary venules. In both cell types, chemokines can transduce signals that convert integrin αLβ2 to a high-affinity conformation, which interacts with ICAM-1 to mediate arrest. In neutrophils, selectins also trigger an immunoreceptor-like signaling cascade that converts integrin αLβ2 to an intermediate-affinity conformation, which interacts with ICAM-1 to slow rolling. It is not known whether selectins induce similar signaling events in T cells. Ag engagement causes phosphorylation of ITAMs on the TCR; these motifs recruit kinases and adaptors that lead to the activation of αLβ2. We found that mouse Th1 cells rolling on P- or E-selectin triggered signals that promoted αLβ2-dependent slow rolling on ICAM-1 in vitro and in vivo. The selectin signaling cascade resembled that used by the TCR, except that unexpectedly, Th1 cells employed the ITAM-bearing protein DAP12, which was not known to be expressed in these cells. Importantly, outside-in signaling through ligand-occupied αLβ2 also required DAP12. Cooperative selectin and chemokine signaling in Th1 cells promoted αLβ2-dependent slow rolling and arrest in vitro and in vivo and migration into Ag-challenged tissues in vivo. Our findings reveal an important function for DAP12 in Th1 cells and a new mechanism to recruit effector T cells to sites of inflammation.

PMID:
31757864
DOI:
10.4049/jimmunol.1900680

Supplemental Content

Full text links

Icon for HighWire
Loading ...
Support Center