Germline deletion of CIN85 in humans with X chromosome-linked antibody deficiency.

Ubiquitously expressed Cbl-interacting protein of 85 kD (CIN85) is a multifunctional adapter molecule supposed to regulate numerous cellular processes that are critical for housekeeping as well as cell type-specific functions. However, limited information exists about the in vivo roles of CIN85, because only conditional mouse mutants with cell type-specific ablation of distinct CIN85 isoforms in brain and B lymphocytes have been generated so far. No information is available about the roles of CIN85 in humans.

Fc gamma receptor IIb modulates the molecular Grb2 interaction network in activated B cells.

B cells require signals transduced by the B cell antigen receptor (BCR) to provide humoral adaptive immunity. These signals are modulated by co-receptors like the Fcγ receptor IIb (FcγRIIb) that prevents activation of B cells after co-ligation with the BCR. Positive and negative effectors need to be precisely organized into signaling complexes, which requires adapter proteins like the growth factor receptor-bound protein 2 (Grb2).

C5a anaphylatoxin as a product of complement activation up-regulates the complement inhibitory factor H in rat Kupffer cells.

The 155-kDa complement regulator factor H (FH) is the predominant soluble regulatory protein of the complement system. It acts as a cofactor for the factor I-mediated conversion of the component C3b to iC3b, competes with factor B for a binding site on C3b and C3(H2O) and promotes the dissociation of the C3bBb complex. The primary site of synthesis is the liver, i.