KLRG ⁺ invariant natural killer T cells are long-lived effectors

Abstract

Significance Both natural killer (NK) cells and γδT cells, classified as innate immune cells, recently have been shown to have features of memory cells. However, after activation, a memory fate of invariant NK T cells (iNKT cells) has not been identified. Here we show the presence of effector memory-like KLRG1 + (Killer cell lectin-like receptor subfamily G, member 1–positive) iNKT cells in the lung. The KLRG1 + iNKT cells are able to recognize and respond to an antigen in the context of CD1d and can persist for a long time and then mount a potent secondary response upon encountering with the same antigen months later. In addition, we suggest that the KLRG1 + iNKT cells could contribute extensively to immune surveillance, especially in preparation for a possible encounter with tumor diseases.

Co-administration of α-GalCer analog and TLR4 agonist induces robust CD8 + T-cell responses to PyCS protein and WT-1 antigen and activates memory-like effector NKT cells

“…In addition to the T-cell responses, the direct antitumor properties of this Th1 memory-like NKT-cell subset could act synergistically to the WT-1-specific CD8 + T-cell responses and increase the therapeutic effect of this vaccine formulation for treating advanced stage tumors. In fact, these results are corroborated by recent findings that indicate memory properties in NKT-cell subsets [44–46]. The ancient paradigm of immunological memory being regarded as a unique feature of the adaptive immune response mediated in an antigen-specific manner by T and B lymphocytes has been challenged previously and no longer stands the trial of evidence [47].…”

“…Persistent IFN-γ-producing i NKT-cell response was previously reported after stimulation with α-GalCer-loaded DCs [44]. Prolonged activation of i NKT cells by CD1d ligand-loaded DCs has demonstrated the surprising presence of effector memory-like i NKT cells in the lung of mice [46]. …”

Diabetes Mellitus Directs NKT Cells Toward Type 2 and Regulatory Phenotype / Diabetes Melitus Usmerava Diferencijaciju NKT Celija U Pravcu Tip 2 I Regulatornog Fenotipa

“…Further, hyperglycaemia did not affect the percentage of splenic CD3 + CD49 + NKT cells that express activatory receptor NKP46, while it increased the frequency of NKT cells that express inhibitory receptor KLRG1 (Figure 2). Shimizu et al showed that KLRG1 + iNKT cells coexpress CD49d and granzyme A live longer than conventional NKT cells and have the potential to be involved in a second immune response on the same antigen (37). In our study, we focused on all subpopulations of NKT cells, not only iNKT cells.…”

Systemic DC Activation Modulates the Tumor Microenvironment and Shapes the Long-Lived Tumor-Specific Memory Mediated by CD8+ T Cells

“…Tumor-associated DCs were sorted and directly subjected to cDNA synthesis using a CellsDirect One-Step qRT-PCR Kit (Invitrogen) with a mixture of pooled gene-specific primers (Supplementary Table S2). Synthesized cDNA was appropriately diluted with water and used as template for subsequent quantitative PCR as described previously (25).…”