Establishment of a vascular endothelial cell-reactive type II NKT cell clone from a rat model of autoimmune vasculitis

Abstract

We previously generated a rat model that spontaneously developed small vessel vasculitis (SVV). In this study, a T cell clone reactive with rat vascular endothelial cells (REC) was established and named VASC-1. Intravenous injection of VASC-1 induced SVV in normal recipients. VASC-1 was a TCRαβ/CD3-positive CD4/CD8 double-negative T cell clone with expression of NKG2D. The cytokine mRNA profile under unstimulated condition was positive for IL-4 and IFN-γ but negative for IL-2 and IL-10. After interaction with REC, the mRNA expression of IL-2, IL-5 and IL-6 was induced in VASC-1, which was inhibited by blocking of CD1d on the REC surface. Although the protein levels of these cytokines seemed to be lower than the detection limit in the culture medium, IFN-γ was detectable. The production of IFN-γ from the VASC-1 stimulated with LPS-pre-treated REC was inhibited by the CD1d blockade on the REC. These findings indicated VASC-1 as an NKT cell clone. The NKT cell pool includes two major subsets, namely types I and II. Type I NKT cells are characterized by expression of semi-invariant TCRs and the potential to bind to marine sponge-derived α-galactosylceramide (α-GalCer) loaded on CD1d; whereas, type II NKT cells do not manifest these characteristics. VASC-1 exhibited a usage of TCR other than the type I invariant TCR α chain and did not bind to α-GalCer-loaded CD1d; therefore, it was determined as a type II NKT cell clone. The collective evidence suggested that REC-reactive type II NKT cells could be involved in the pathogenesis of SVV in rats.

The Role of CD1d and MR1 Restricted T Cells in the Liver

“…In a mouse bone marrow transplantation model, donor type II NKT cells inhibit graft-vs.-host disease via releasing IL-4 ( 37 ). In a rat model, activating type II NKT cells with SCP2 peptide promotes the inflammatory response through production of inflammatory cytokines IL-5 and IL-6 ( 38 ). In an iNKT cell-deficient (Jα18 −/− ) mouse model, Sagami et al found adoptive transfer of type II NKT cells exacerbated DSS-induced colitis ( 39 ).…”

Detection of Autoreactive Type II NKT Cells: A Pilot Study of Comparison Between Healthy Individuals and Patients with Vasculitis

“…Liao et al demonstrated that the disordered regulation of CD1d-restricted type II NKT cells could cause the spontaneous development of colitis in CD1d transgenic mice (8). In addition, we have shown that proinflammatory autologous vascular endothelial cell-reactive CD1d-restricted type II NKT cells were involved in the development of vasculitis in rats (9). Recently, we identified P 518-532 of rat sterol carrier protein 2 (rSCP2 518-532 ), FFQGKLKIAGNMGLA, as the epitope, which was recognized by one such CD1d-restricted type II NKT cell (10).…”

“…Terabe et al showed that CD1d-restricted type II NKT cells were essential for the down-regulation of tumor immunosurveillance in mice (7). In addition, we have shown that proinflammatory autologous vascular endothelial cell-reactive CD1d-restricted type II NKT cells were involved in the development of vasculitis in rats (9). Liao et al demonstrated that the disordered regulation of CD1d-restricted type II NKT cells could cause the spontaneous development of colitis in CD1d transgenic mice (8).…”

CD1d-Restricted Type II NKT Cells Reactive With Endogenous Hydrophobic Peptides

“…More recently, our group has revealed the involvement of pro-inflammatory type II NKT cells that are reactive with the endogenous SCP2 peptide in the pathogenesis of small vessel vasculitis in rats ( 25 , 62 ) (Figure 1 B). CD1d-restricted type II NKT cells activated by the SCP2 peptide function to enhance inflammation by producing pro-inflammatory cytokines.…”