First Author | May RM | Year | 2013 |
Journal | Blood | Volume | 121 |
Issue | 16 | Pages | 3135-46 |
PubMed ID | 23407547 | Mgi Jnum | J:196459 |
Mgi Id | MGI:5488541 | Doi | 10.1182/blood-2012-12-474361 |
Citation | May RM, et al. (2013) Murine natural killer immunoreceptors use distinct proximal signaling complexes to direct cell function. Blood 121(16):3135-46 |
abstractText | Signaling pathways leading to natural killer (NK)-cell effector function are complex and incompletely understood. Here, we investigated the proximal signaling pathways downstream of the immunotyrosine-based activation motif (ITAM) bearing activating receptors. We found that the adaptor molecule SH2 domain-containing leukocyte protein of 76 kD (SLP-76) is recruited to microclusters at the plasma membrane in activated NK cells and that this is required for initiation of downstream signaling and multiple NK-cell effector functions in vitro and in vivo. Surprisingly, we found that 2 types of proximal signaling complexes involving SLP-76 were formed. In addition to the canonical membrane complex formed between SLP-76 and linker for activation of T cells (LAT) family members, a novel LAT family-independent SLP-76-dependent signaling pathway was identified. The LAT family-independent pathway involved the SH2 domain of SLP-76 and adhesion and degranulation-promoting adaptor protein (ADAP). Both the LAT family-dependent and ADAP-dependent pathway contributed to interferon-gamma production and cytotoxicity; however, they were not essential for other SLP-76-dependent events, including phosphorylation of AKT and extracellular signal-related kinase and cellular proliferation. These results demonstrate that NK cells possess an unexpected bifurcation of proximal ITAM-mediated signaling, each involving SLP-76 and contributing to optimal NK-cell function. |