""""""""Studies were performed to examine the human immune response in normal individuals and in patients with congenital and acquired immunodeficiency states associated with a high frequency of cancer. Interleukin-2 (IL-2) and the IL-2 receptor (IL-2R) play pivotal roles in the immune response. Previously we discovered a soluble form of the IL-2R alpha subunit (sIL-2Ra) and demonstrated abnormal levels of sIL-2Ra in patients with several disorders of immune function including cancer and AIDS. A recently discovered lymphokine, IL-15, shares many functional similarities with IL-2. We have shown that IL-15 stimulates the release of sIL-2Ra from both resting and activated cells in vitro and in vivo; suggesting the possibility that in certain disorders IL-15 may contribute to abnormalities of immune function and elevated sIL-2Ra levels in vivo. We continued studies on the primary immunodeficiency disorders. Two forms of X-linked agammaglobulinemia have been described: Bruton's agammaglobulinemia (XLA) due to defects in Bruton's tyrosine kinase (Btk) and agammaglobulinemia associated with growth hormone deficiency (XLA/GHD). Examination of Btk in patients with XLA/GHD revealed a normal abundance of normal sized BTK transcripts, normal BTK cDNA sequences, normal amounts of expressed Btk protein and normal Btk enzymatic activity. These studies establish XLA/GHD as a disease distinct from XLA and suggest additional X-chromosome genes critical for B-cell development. The function of the protein product of the gene responsible for the Wiskott-Aldrich syndrome (WASP) has not been defined. We have produced monoclonal antibodies to WASP and have studied its expression and function in normal and Wiskott-Aldrich syndrome patients. This cytoplasmic protein is expressed in platelets, monocytes, T-cells and B-cells. Some patients with the Wiskott-Aldrich syndrome (WAS) produce a non-functional protein whose sequence has been defined while others do not - indicating critical residues for WASP function. The WASP has been shown to interact with several signaling proteins including phospholipase C gamma, PI3' kinase, src and fgr indicating that WASP may play a critical role in cytoskeletal organization and intracellular signaling to the nucleus. We demonstrated a phenotypic abnormality in WAS cells namely aberrant cytoskeletal actin organization and using retroviral-mediated gene transfer we were able to correct this abnormality. A rapid diagnostic test for WAS was developed using permeabilized flow cytometry. Additional proteins interacting with WASP were identified using a """"""""""""""""two hybrid"""""""""""""""" screen and one interacter was a previously unpublished Genbank sequence, HS-PRPL2. Mutations in the WASP protein which occur in patients diminished the WASP-HS-PRPL2 interaction suggesting a physiological relevance. Additional studies of WASP function may shed insight into the increased incidence of lymphoma in these patients.""""""""

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Intramural Research (Z01)
Project #
1Z01SC004017-20
Application #
6123643
Study Section
Metabolism Study Section (MET)
Project Start
Project End
Budget Start
Budget End
Support Year
20
Fiscal Year
1998
Total Cost
Indirect Cost
Name
National Cancer Institute Division of Clinical Sciences
Department
Type
DUNS #
City
State
Country
United States
Zip Code
Wada, Taizo; Konno, Akihiro; Schurman, Shepherd H et al. (2003) Second-site mutation in the Wiskott-Aldrich syndrome (WAS) protein gene causes somatic mosaicism in two WAS siblings. J Clin Invest 111:1389-97