Chemokine-dependent migration of lymphocytes and dendritic cells (DCs) into specific anatomic compartments is essential to optimal T cell immune responses against foreign pathogens. The p110? isoform of the phosphatidyolinositol 3-kinase (PI 3-K) family of lipid kinases is activated by chemokine receptors and other G protein coupled receptors. Lipid products produced by PI 3-K are essential in forming polarized morphologies necessary for directional cell migration and PI 3-K can regulate chemokine-dependent integrin activation. Neutrophils and macrophages from mice deficient in poly exhibit impaired migration to multiple chemotactic stimuli. While p110gamma -/- mice also exhibit impaired CDS T cell anti-viral responses and CD4 T cell-dependent antibody responses, naive T cell migration both in vitro and in vivo is not dependent on p110gamma. However, migration of p110gamma -/- effector T cells into inflammatory sites is dramatically impaired, and p110gamma -/- mice have reduced numbers of DCs in secondary lymphoid organs. Thus, we propose that p110gamma regulates T cell immune responses by specifically regulating DC trafficking into secondary lymphoid organs that is critical for naive T cell priming, and the subsequent migration of effector T cells into inflammatory sites.
In Aim 1, we will define the role that p110gamma plays in chemokine-dependent integrin activation and cell polarization on effector T cells.
In Aim 2, we will utilize adoptive transfer approaches with wild-type and p110gamma -/- mice to determine the function of p110gamma on CD4 T cell activation in vivo, chemokine-dependent migration of activated T cells in lymph nodes and into non-lymphoid tissue, and DC trafficking and function.
In Aim 3, we will define the role of p110gamma in regulating the activation and migration of CDS T cells in response to vaccinia virus. These studies will provide important new insights into the mechanism by which p110gamma regulates T cell-specific immune responses via regulation of T cell and DC migration. Defining the function of p110gamma in regulating homeostatic versus inflammatory trafficking in vivo is critical to the potential utility of p110gamma as an anti-inflammatory drug target. Finally, these studies will provide new insights into T cell responses to vaccinia, which will be critical to the development of more effective smallpox vaccines that have fewer adverse effects.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI064271-05
Application #
7576186
Study Section
Special Emphasis Panel (ZRG1-IHD (01))
Program Officer
Miller, Lara R
Project Start
2005-09-15
Project End
2010-11-28
Budget Start
2009-03-01
Budget End
2010-11-28
Support Year
5
Fiscal Year
2009
Total Cost
$271,202
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Pathology
Type
Schools of Medicine
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Denucci, Christopher C; Mitchell, Jason S; Shimizu, Yoji (2009) Integrin function in T-cell homing to lymphoid and nonlymphoid sites: getting there and staying there. Crit Rev Immunol 29:87-109
Thomas, Molly S; Mitchell, Jason S; DeNucci, Christopher C et al. (2008) The p110gamma isoform of phosphatidylinositol 3-kinase regulates migration of effector CD4 T lymphocytes into peripheral inflammatory sites. J Leukoc Biol 84:814-23
Martin, Amanda L; Schwartz, Matthew D; Jameson, Stephen C et al. (2008) Selective regulation of CD8 effector T cell migration by the p110 gamma isoform of phosphatidylinositol 3-kinase. J Immunol 180:2081-8