Inhibition of IgE and IgE/anti-IgE mediated responses in mast cells by Omalizumab

Inhibition of IgE and IgE/anti-IgE mediated responses in mast cells by Omalizumab

Results Omalizumab (10 ug/mL) inhibited IgE binding to LAD2 cells by 78% (P=0.007) compared to untreated control. Omalizumab (10 ug/mL) further blocked IgE-dependent upregulation of FcεRI expression by 90% (P=0.03). In addition, omalizumab removed FcεRI-bound IgE in a time-dependent manner; an effect that was detected as early as 24 hrs (57% removal; P<0.001) after addition of omalizumab result...

Structural basis of omalizumab therapy and omalizumab-mediated IgE exchange

Omalizumab is a widely used therapeutic anti-IgE antibody. Here we report the crystal structure of the omalizumab-Fab in complex with an IgE-Fc fragment. This structure reveals the mechanism of omalizumab-mediated inhibition of IgE interactions with both high- and low-affinity IgE receptors, and explains why omalizumab selectively binds free IgE. The structure of the complex also provides mecha...

IgE-mediated desensitization in human basophils and mast cells.

Secretion from mast cells and basophils, two cells central to immediate hypersensitivity reactions, has characteristics that suggest the existence of intrinsic signal transduction processes that limit the extent of the cell's response. This process(es) has been termed desensitization. One goal of current research efforts is to determine the mechanisms used by mast cells and basophils to down-re...

Blunted IgE-Mediated Activation of Mast

IgE-mediated anaphylactic degranulation of isolated human skin mast cells.

Isolated human skin mast cells (HSMC) were prepared and cultured overnight before functional and electron microscopic studies. Mast cell suspensions were examined after stimulation with anti-IgE to produce anaphylactic degranulation or examined in buffer-incubated controls. Histamine release was measured in replicate samples. Control, isolated HSMC studied by electron microscopy were well prese...