title: The loss of RGS protein-Gα(i2) interactions results in markedly impaired mouse neutrophil trafficking to inflammatory sites.
abstract: Neutrophils are first responders rapidly mobilized to inflammatory sites by a tightly regulated, nonredundant hierarchy of chemoattractants. These chemoattractants engage neutrophil cell surface receptors triggering heterotrimeric G-protein Gα(i) subunits to exchange GDP for GTP. By limiting the duration that Gα(i) subunits remain GTP bound, RGS proteins modulate chemoattractant receptor signaling. Here, we show that neutrophils with a genomic knock in of a mutation that disables regulator of G-protein signaling (RGS)-Gα(i2) interactions accumulate in the bone marrow and mobilize poorly to inflammatory sites. These defects are attributable to enhanced sensitivity to background signals, prolonged chemoattractant receptor signaling, and inappropriate CXCR2 downregulation. Intravital imaging revealed a failure of the mutant neutrophils to accumulate at and stabilize sites of sterile inflammation. Furthermore, these mice could not control a nonlethal Staphylococcus aureus infection. Neutrophil RGS proteins establish a threshold for Gα(i) activation, helping to coordinate desensitization mechanisms. Their loss renders neutrophils functionally incompetent.
authors.affiliation: B-Cell Molecular Immunology Section, Laboratory of Immunoregulation, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA. hcho@niaid.nih.gov
authors.forename: Hyeseon
authors.initials: H
authors.lastname: Cho
authors.forename: Olena
authors.initials: O
authors.lastname: Kamenyeva
authors.forename: Sunny
authors.initials: S
authors.lastname: Yung
authors.forename: Ji-Liang
authors.initials: JL
authors.lastname: Gao
authors.forename: Il-Young
authors.initials: IY
authors.lastname: Hwang
authors.forename: Chung
authors.initials: C
authors.lastname: Park
authors.forename: Philip M
authors.initials: PM
authors.lastname: Murphy
authors.forename: Richard R
authors.initials: RR
authors.lastname: Neubig
authors.forename: John H
authors.initials: JH
authors.lastname: Kehrl
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000276:immunology / Q000473:pathology; D002633:Chemotaxis / Q000235:genetics* / Q000276:immunology; D015536:Down-Regulation; D004789:Enzyme Activation; D051960:GTP-Binding Protein alpha Subunit, Gi2 / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D055879:Gene Knock-In Techniques; D006153:Guanosine Diphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism; D007249:Inflammation / Q000150:complications / Q000201:enzymology* / Q000276:immunology / Q000382:microbiology; D051379:Mice; D008822:Mice, Transgenic; D009154:Mutation; D009504:Neutrophils / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D020710:RGS Proteins / Q000235:genetics / Q000276:immunology / Q000378:metabolism*; D023063:Receptors, Interleukin-8B / Q000235:genetics / Q000276:immunology; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology; D013203:Staphylococcal Infections / Q000150:complications / Q000201:enzymology* / Q000276:immunology / Q000382:microbiology; D013211:Staphylococcus aureus / Q000502:physiology; D013997:Time Factors
chemical_list: D020710:RGS Proteins; D023063:Receptors, Interleukin-8B; D006153:Guanosine Diphosphate; D006160:Guanosine Triphosphate; D051960:GTP-Binding Protein alpha Subunit, Gi2; C498016:Gnai2 protein, mouse