• Liu, Fu-Tong (PI)

Project: Research project

Project Details


Fc receptors for IgE (FcR Gamma) have been identified on various cell
types, including mast cells, basophils, macrophages and lymphocytes. The
receptors on mast cells and basophils are directly involved in the
IgE-mediated hypersensitivity reactions. FcR Gamma-bearing lymphocytes are
important for the regulation of the IgE antibody response. The objective
of this research is to study the gene expression, structure and function of
this group of receptors, applying recombinant DNA technology. First, the gene and protein structure of FcR Gamma will be determined. We
have already cloned cDNA coding for an FcR Gamma protein found in basophils
and the relationship of this protein to previously identified subunits of
the basophil FcR Gamma will be established. Genes for other subunits of
the basophil FcR Gamma and the gene for the lymphocyte FcR Gamma will be
cloned. Structural homology between basophil and lymphocyte FcR Gamma will
be determined. Second, the structure-function relationship of FcR Gamma will be
established. The subunits of basophil FcR Gamma required for expressing
IgE-binding activity on the cell surface and for transmitting signals for
the activation of basophils will be determined. This study will be
performed by translation in Xenopus oocytes of mRNA coding for FcR Gamma
subunits or by transfection of appropriate cells with cloned genes. To
establish the function of lymphocyte FcR Gamma, the relationship between
the receptor and IgE-binding factors, previously identified to be involved
in the regulation of IgE responses and structurally-related to the
receptor, will be determined. The cloned lymphocyte FcR Gamma gene will be
used for this study. Third, the mechanism of regulation of FcR Gamma gene expression will be
elucidated. The cloned genes for basophil or lymphocyte FcR Gamma will be
used as probes to study the expression of FcR Gamma in various cell types
under various conditions. DNA sequences in the receptor genes controlling
the level and possibly the tissue specificity of FcR Gamma gene expression
will be identified. It is known that lymphocytes respond to exposure to
IgE by an increase in the expression of FcR Gamma. The DNA sequence of the
lymphocyte FcR Gamma gene that is involved in such a response will be
determined. Results from these studies should advance our understanding of human
allergic disorders significantly as well as provide invaluable insights
into the mechanisms of regulations and effector functions in the immune
system in general.
Effective start/end date5/1/822/28/95


  • National Institutes of Health: $211,351.00
  • National Institutes of Health: $41,072.00


  • Medicine(all)
  • Immunology and Microbiology(all)


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