Loss of SLP-76 expression within myeloid cells confers resistance to neutrophil-mediated tissue damage while maintaining effective bacterial killing

RA Clemens, LE Lenox, T Kambayashi… - The Journal of …, 2007 - journals.aai.org
RA Clemens, LE Lenox, T Kambayashi, N Bezman, JS Maltzman, KE Nichols, GA Koretzky
The Journal of Immunology, 2007journals.aai.org
The Src homology 2 domain-containing leukocyte phosphoprotein of 76 kDa (SLP-76) is an
adaptor molecule critical for immunoreceptor and integrin signaling in multiple hemopoietic
lineages. We showed previously that SLP-76 is required for neutrophil function in vitro,
including integrin-induced adhesion and production of reactive oxygen intermediates, and to
a lesser extent, FcγR-induced calcium flux and reactive oxygen intermediate production. It
has been difficult to determine whether SLP-76 regulates neutrophil responses in vivo …
Abstract
The Src homology 2 domain-containing leukocyte phosphoprotein of 76 kDa (SLP-76) is an adaptor molecule critical for immunoreceptor and integrin signaling in multiple hemopoietic lineages. We showed previously that SLP-76 is required for neutrophil function in vitro, including integrin-induced adhesion and production of reactive oxygen intermediates, and to a lesser extent, FcγR-induced calcium flux and reactive oxygen intermediate production. It has been difficult to determine whether SLP-76 regulates neutrophil responses in vivo, because Slp-76−/− mice exhibit marked defects in thymocyte and vascular development, as well as platelet and mast cell function. To circumvent these issues, we generated mice with targeted loss of SLP-76 expression within myeloid cells. Neutrophils obtained from these animals failed to respond to integrin activation in vitro, similar to Slp-76−/− cells. Despite these abnormalities, SLP-76-deficient neutrophils migrated normally in vivo in response to Staphylococcus aureus infection and efficiently cleared micro-organisms. Interestingly, SLP-76-deficient neutrophils did not induce a robust inflammatory response in the localized Shwartzman reaction. Collectively, these data suggest that disruption of integrin signaling via loss of SLP-76 expression differentially impairs neutrophil functions in vivo, with preservation of migration and killing of S. aureus but reduction in LPS-induced tissue damage and vascular injury.
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