Natural killer T (NKT) cells recognize lipid antigens presented by CD1d molecules and can be classified into type I or type II based upon their usage of a semi-invariant TCR or diverse TCRs, respectively. Type II NKT cells are predominant in humans, whereas type I NKT cells are prevalent in the mouse. The biology and function of self-glycolipid-reactive CD1d-restricted type II NKT cells is poorly understood. We have identified a major subset of type II NKT cells that recognizes a myelin-derived glycolipid, sulfatide. Sulfatide-reactive type II but not type I NKT cells are enriched in the inflamed tissues during experimental autoimmune encephalomyelitis (EAE). Importantly, sulfatide-mediated activation of type II NKT cells induce a novel regulatory pathway accompanied by anergy induction in type I NKT cells and protection from autoimmune diseases. Here we propose to characterize in details the TCR V-gene repertoire of type II NKT cells with respect to the antigen fine specificity, tissue distribution and cytokine secretion pattern. Also we will study their activation and mechanism of immune regulation that involves interactions of NKT cells with other innate-like cells, including plasmacytoid dendritic cells (pDCs), myeloid-derived suppressor cells (MDSCs) which in turn control adaptive immunity. The TCR repertoire of sulfatide/CD1d-tetramer-sorted cells will be determined using flow cytometry, DNA sequencing and spectratyping of TCR V1 and V2 genes. Following determination of antigen specificity using retroviral vector-mediated transfection of dominant TCR 1 and 2 chain genes into a TCR-deficient cell line, most affine TCRs will be folded with sulfatide-loaded CD1d molecules for structural studies of the tri-molecular complex. The impact of the absence or presence of an excess amount of endogenous sulfatide on the TCR repertoire will be studied in ceramide galactosyl sulfotransferase CST-/- or saposin B-/- mice, respectively. The role of B cells in the activation of type II NKT cells and their regulatory ability will be investigated using B cell-deficient 5MT mice and their bone marrow chimeras. Since several autoimmune conditions are associated with the anti-sulfatide antibody response, the ability of type II NKT cells to provide help for the antibody response will be examined in CD1d-/-, J118-/- and type II NKT-depleted mice as well as in recipients of sulfatide/CD1d-tetramer+ cells. The role of pDCs vs. mDCs in activation of type II NKT cells and in regulation will be studied using CFSE-labeled CD1d-tetramer+ cells in CD1d-/- recipients. The role of type II NKT cells in the accumulation of MDSCs and their ability to suppress the encephalitogenic CD4+ T cells will be examined in adoptive transfer assays and following their impairment in mice treated with all-trans-retinoic acid. These studies are important not only for understanding the biology of type II NKT cells and the mechanisms of immune regulation, but also because of the highly conserved nature of CD1d molecules across species they will form the basis for manipulation of autoimmune diseases in humans and will have implications for augmenting anti-tumor immune responses.

Public Health Relevance

We have identified a distinct population of white blood lymphocytes that becomes activated by a self-glycolipid and is present in both mice and in humans. Upon their activation these cells are able to prevent and treat experimental autoimmune diseases mimicking multiple sclerosis (MS) in humans. This proposal seeks to understand the mechanism by which these lymphocytes control disease-causing cells in an effort to develop novel therapeutic approaches for the treatment of such diseases.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA100660-09
Application #
8473803
Study Section
Innate Immunity and Inflammation Study Section (III)
Program Officer
Howcroft, Thomas K
Project Start
2003-04-01
Project End
2015-05-31
Budget Start
2013-06-01
Budget End
2014-05-31
Support Year
9
Fiscal Year
2013
Total Cost
$328,591
Indirect Cost
$146,040
Name
Torrey Pines Institute for Molecular Studies
Department
Type
DUNS #
605758754
City
Port Saint Lucie
State
FL
Country
United States
Zip Code
34987
Maricic, Igor; Girardi, Enrico; Zajonc, Dirk M et al. (2014) Recognition of lysophosphatidylcholine by type II NKT cells and protection from an inflammatory liver disease. J Immunol 193:4580-9
Kumar, Vipin; Delovitch, Terry L (2014) Different subsets of natural killer T cells may vary in their roles in health and disease. Immunology 142:321-36
Maricic, Igor; Halder, Ramesh; Bischof, Felix et al. (2014) Dendritic cells and anergic type I NKT cells play a crucial role in sulfatide-mediated immune regulation in experimental autoimmune encephalomyelitis. J Immunol 193:1035-46
Arrenberg, Philomena; Maricic, Igor; Kumar, Vipin (2011) Sulfatide-mediated activation of type II natural killer T cells prevents hepatic ischemic reperfusion injury in mice. Gastroenterology 140:646-55
Arrenberg, Philomena; Halder, Ramesh; Dai, Yang et al. (2010) Oligoclonality and innate-like features in the TCR repertoire of type II NKT cells reactive to a beta-linked self-glycolipid. Proc Natl Acad Sci U S A 107:10984-9
Arrenberg, Philomena; Halder, Ramesh; Kumar, Vipin (2009) Cross-regulation between distinct natural killer T cell subsets influences immune response to self and foreign antigens. J Cell Physiol 218:246-50
Parekh, Vrajesh V; Lalani, Saif; Kim, Sungjune et al. (2009) PD-1/PD-L blockade prevents anergy induction and enhances the anti-tumor activities of glycolipid-activated invariant NKT cells. J Immunol 182:2816-26
Halder, Ramesh C; Aguilera, Carlos; Maricic, Igor et al. (2007) Type II NKT cell-mediated anergy induction in type I NKT cells prevents inflammatory liver disease. J Clin Invest 117:2302-12