Differences in the gene expression profile of human monocytic cells activated by high and low affinity Fc-gamma-receptors

Receptors for the constant (Fc) region of immunoglobulin G, play an important role in linking the humoral and cellular arms of immune response. Three different classes of receptors have been defined, FcγRI (CD64), FcγRII (CD 32), and FcγRIII (CD16). We have previously shown that in a human monocyte model (IFNγ-primed U937 cells), FcγRI and FcγRII stimulation trigger two very distinct intracellular signalling pathways. Here we show for the first time, the use of oligonucleotide microarrays to investigate the overall gene-expression profile of human monocytes triggered with FcγRI or FcγRII. Our data indicate that several interesting genes are differentially expressed in response to the different receptors, pointing out to a complete different genetic response of human monocytes regulated by the different signal transduction cascade triggered by FcγRI or FcγRIIa. Thus, providing new insights into the different mechanisms utilized by the different IgG receptors to effect their functions.