Anti-phospholipid antibodies are a type of autoantibody associated with significant cardiovascular pathology, stroke, and recurrent miscarriages. It is not known how these antibodies arise, or whether T cells are involved in their generation. CD1d-restricted T cells are a novel population of T lymphocytes that recognize lipid and glycolipid antigens, including in some cases phospholipids. CD1d molecules are expressed on antigen presenting cells, including B cells. This proposal investigates the hypothesis that anti-phospholipid antibody production by B cells could be regulated by CD1d-restricted T cells in an antigen specific manner. The analysis focuses on whether the presence of elevated levels of pathogenic anti-phospholipid antibodies correlates with changes in the numbers, activation states, functions, or antigen specificities of CD1d-restricted T cells. This will be assessed in the following specific aims: i) flow cytometric analysis will be performed using lipid antigen loaded CD1d tetramers to detect and analyze the functional properties of CD1d-restricted T cells from peripheral blood of patients with anti-phospholipid antibodies compared to control donors; ii) binding of different phospholipids to CD1d molecules will be analyzed using CD1d-Fc fusion proteins and fluorescent or radiolabeled phospholipids; iii) CD1d-restricted T cell clones will be derived from patients with anti-phospholipid antibodies and control donors, and used to investigate reactivity to individual phospholipids, and to test recognition of anti-phospholipid antibody producing B cells. This investigation will provide new insight into the role of autoreactive T cells in the generation of autoantibodies, and may provide new diagnostic and therapeutic approaches for conditions associated with pathogenic anti-phospholipid antibodies.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL071590-04
Application #
7024465
Study Section
Experimental Immunology Study Section (EI)
Program Officer
Rabadan-Diehl, Cristina
Project Start
2003-06-19
Project End
2008-03-31
Budget Start
2006-04-01
Budget End
2008-03-31
Support Year
4
Fiscal Year
2006
Total Cost
$210,677
Indirect Cost
Name
University of Wisconsin Madison
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
161202122
City
Madison
State
WI
Country
United States
Zip Code
53715
Cox, Daryl; Fox, Lisa; Tian, Runying et al. (2009) Determination of cellular lipids bound to human CD1d molecules. PLoS One 4:e5325
Yuan, Weiming; Qi, Xiaoyang; Tsang, Pansy et al. (2007) Saposin B is the dominant saposin that facilitates lipid binding to human CD1d molecules. Proc Natl Acad Sci U S A 104:5551-6
Chen, Xiuxu; Wang, Xiaohua; Keaton, Jason M et al. (2007) Distinct endosomal trafficking requirements for presentation of autoantigens and exogenous lipids by human CD1d molecules. J Immunol 178:6181-90
Gumperz, Jenny E (2006) The ins and outs of CD1 molecules: bringing lipids under immunological surveillance. Traffic 7:2-13
Brigl, Manfred; van den Elzen, Peter; Chen, Xiuxu et al. (2006) Conserved and heterogeneous lipid antigen specificities of CD1d-restricted NKT cell receptors. J Immunol 176:3625-34
Gumperz, Jenny E (2004) CD1d-restricted ""NKT"" cells and myeloid IL-12 production: an immunological crossroads leading to promotion or suppression of effective anti-tumor immune responses? J Leukoc Biol 76:307-13