SLP-76 and Cbl are complex adapter proteins that have the capacity to bind to smaller adapter proteins, such as Grb2, which subsequently binds the nucleotide exchange protein Sos in the transmission of intracellular signals. SLP-76, Cbl, Shc, and Grb2 have been implicated in immunoreceptor tyrosine-based activation motif (ITAM) signaling, leading to activation of Ras. However, their mechanism o...

Cbl is a cytosolic protein that is rapidly tyrosine phosphorylated in response to Fc receptor activation and binds to the adaptor proteins Grb2, CrkL, and Nck. A few reports describe Cbl interactions in primary human hematopoietic cells. We show evidence that Cbl participates in signaling initiated by FcgRI receptor cross-linking in human primary macrophages, and functions downstream of Src fam...

Engagement of the high-affinity IgG Fc receptor (FcgRI) actiSyk nor MAP kinase activation was affected by the presence of ZAP-70. Although transduced ZAP-70 had in vitro kinase vates a signal transduction pathway involving tyrosine phosphorylation of associated kinases. We compared the activity and associated with FceRIg after receptor aggregation, it was not tyrosine phosphorylated. In contras...

Human C-reactive protein (CRP) is an acute phase protein that binds to receptors on human and mouse leukocytes. We have recently determined that the high and low affinity receptors for CRP on human leukocytes are FcgRIIa and FcgRI, respectively. Previous work by others suggested that CRP receptors on mouse macrophages are distinct from FcgR. We have taken advantage of the availability of mice d...

mAb therapy for experimental metastatic melanoma relies on activating receptors for the Fc portion of IgG (FcgR). Opposing results on the respective contribution of mouse FcgRI, FcgRIII, and FcgRIV have been reported using the gp75-expressing B16 melanoma and the protective anti-gp75 mAb TA99. We analyzed the contribution of FcgRs to this therapy model using bioluminescent measurement of lung m...

Introduction Cluster of Differentiation 64 (CD64) antigen is a membrane glycoprotein expressed on monocytes and macrophages. It is the high affinity neutrophil FcgRI receptor which is weakly expressed by neutrophils at physiological levels, but strongly upregulated within 4-6 hours by the pleiotropic cytokines such as Interferon-g (IFN-g) and Granulocyte Colony Stimulating Factor (G-CSF) which ...

background: neonatal sepsis is a life-threatening disease with an incidence of 1 to 10 per 1000 live births and a mortality rate of 15% to 50%. the clinical signs are non-specific and indistinguishable from those caused by a variety of neonatal noninfectious disorders. objective: the aim of this study was to determine the importance of cd64 expression (fcgri), a neutrophil surface marker, in ea...

BACKGROUND Adipose-derived stem cells (ASCs) are mesenchymal stem cells (MSCs) derived from adipose tissue. MSCs have multiple properties including anti-inflammatory and immunomodulatory effects in various disease models and human diseases. However, the mechanisms underlying this wide range of effects need to be explored. METHODS Collagen antibody-induced arthritis (CAIA) is a unique model in...

There are three major classes of human Fcg receptors (FcgRI, FcgRII, and FcgRIII) and various isoforms of each class are capable of mediating phagocytosis. FcgRIIA is an unusual Fcg receptor in that it transmits a phagocytic signal in the absence of an additional receptor subunit. The cytoplasmic domain of FcgRIIA contains a conserved motif containing two copies of the sequence YXXL. The tyrosi...