We have recently developed model systems to study the mammalian cellular function of Rho GTPases (e.g., Cdc42) and the Wiskott-Aldrich syndrome proteins (e.g., WASP, N-WASP, WAVEs) - two interacting families of proteins that integrate incoming cell surface signals to mediate cytoskeletal change. WASPs are cytoplasmic proteins that when activated by Rho-family GTPases (Cdc42/Rac) and phosphoinositides directly bind to the Arp2/3 complex, resulting in actin assembly. In this context, coordination of cell shape through cytoskeletal change is required for such diverse properties as cell-cell contact, lymphocyte activation, and chemotaxis. WASP activation is also regulated by interaction with several other proteins including the WASP-interacting protein (WIP), Sh3 domain proteins (e.g. Nek) and Srk family kinases (e.g., Hck). We have employed gene-targeting to generate mice deficient for the Rho-family GTPase Cdc42 as well as several WASP family members: WASP, N-WASP, and WAVE-2. N-WASP- and WAVE-2- deficiencies result in early embryonic lethality whereas WASP-deficient (WKO) mice are viable and fertile, with lymphocytes that develop normally but have signaling and cytoskeletal abnormalities. We have also generated ES cells clones that contained an activated WASP knock-in mutation associated with the recently described novel immunodeficiency, X-linked Neutropenia (XLN). Because N-WASP and WAVE-2 deficiencies were not viable, selective targetings of these alleles were required to assess the role of these proteins in lymphocytes. To this end, we have generated mice with N-WASP that can be conditionally inactivated in leukocytes, and we are currently generating mice with similar mutations in WAVE2. We have generated WASP/N-WASP double knock-out (DKO) mice in T cells and, in collaboration with Dr. Raif Geha (Project 1), WASP/WIP DKO mice;both strains are associated with more severe signaling and cytoskeletal abnormalities in T cells when compared to WKO mice. This collection of novel reagents, in which the various WASP-family members can be inactivated, singularly or in combination and in either cells or mice, provides a powerful basis for our ongoing goals of dissecting the roles of WASP family members in leukocyte function. We propose: A1) To dissect the unique role of WASP and the combined role of WASP/N-WASP in leukocyte development and function. A2) To define the role of constitutively-active mutations in WASP function in T cells.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Program Projects (P01)
Project #
5P01HL059561-13
Application #
8147996
Study Section
Heart, Lung, and Blood Initial Review Group (HLBP)
Project Start
2010-09-01
Project End
2013-08-31
Budget Start
2010-09-01
Budget End
2011-08-31
Support Year
13
Fiscal Year
2010
Total Cost
$419,765
Indirect Cost
Name
Children's Hospital Boston
Department
Type
DUNS #
076593722
City
Boston
State
MA
Country
United States
Zip Code
02115
Garber, John J; Mallick, Emily M; Scanlon, Karen M et al. (2018) Attaching-and-Effacing Pathogens Exploit Junction Regulatory Activities of N-WASP and SNX9 to Disrupt the Intestinal Barrier. Cell Mol Gastroenterol Hepatol 5:273-288
Vardi, Iddo; Barel, Ortal; Sperber, Michal et al. (2018) Genetic and Structural Analysis of a SKIV2L Mutation Causing Tricho-hepato-enteric Syndrome. Dig Dis Sci 63:1192-1199
Li, Jian; Shouval, Dror S; Doty, Andria L et al. (2017) Increased Mucosal IL-22 Production of an IL-10RA Mutation Patient Following Anakin Treatment Suggests Further Mechanism for Mucosal Healing. J Clin Immunol 37:104-107
Lexmond, Willem S; Goettel, Jeremy A; Lyons, Jonathan J et al. (2016) FOXP3+ Tregs require WASP to restrain Th2-mediated food allergy. J Clin Invest 126:4030-4044
Baptista, Marisa A P; Keszei, Marton; Oliveira, Mariana et al. (2016) Deletion of Wiskott-Aldrich syndrome protein triggers Rac2 activity and increased cross-presentation by dendritic cells. Nat Commun 7:12175
Volpi, Stefano; Santori, Elettra; Abernethy, Katrina et al. (2016) N-WASP is required for B-cell-mediated autoimmunity in Wiskott-Aldrich syndrome. Blood 127:216-20
Moran, Christopher J; Klein, Christoph; Muise, Aleixo M et al. (2015) Very early-onset inflammatory bowel disease: gaining insight through focused discovery. Inflamm Bowel Dis 21:1166-75
Crestani, Elena; Volpi, Stefano; Candotti, Fabio et al. (2015) Broad spectrum of autoantibodies in patients with Wiskott-Aldrich syndrome and X-linked thrombocytopenia. J Allergy Clin Immunol 136:1401-4.e1-3
Kolhatkar, Nikita S; Brahmandam, Archana; Thouvenel, Christopher D et al. (2015) Altered BCR and TLR signals promote enhanced positive selection of autoreactive transitional B cells in Wiskott-Aldrich syndrome. J Exp Med 212:1663-77
Gerasimcik, Natalija; Dahlberg, Carin I M; Baptista, Marisa A P et al. (2015) The Rho GTPase Cdc42 Is Essential for the Activation and Function of Mature B Cells. J Immunol 194:4750-8

Showing the most recent 10 out of 110 publications