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Updated: Sep 26, 2026
Purification and Expansion of Mouse Invariant Natural Killer T Cells for in vitro and in vivo Studies
Published on: February 15, 2021
Ligand-dependent inhibition of CD1d-restricted NKT cell development in mice transgenic for the activating receptor
Roger B Voyle1, Friedrich Beermann, Rosemary K Lees
1Ludwig Institute for Cancer Research, Chemin des Boveresses 155, CH-1066 Epalinges, Switzerland. hughrobson.macdonald@isrec.unil.ch
Abstract:
In addition to their CD1d-restricted T cell receptor (TCR), natural killer T (NKT) cells express various receptors normally associated with NK cells thought to act, in part, as modulators of TCR signaling. Immunoreceptor-tyrosine activation (ITAM) and inhibition (ITIM) motifs associated with NK receptors may augment or attenuate perceived TCR signals respectively, potentially influencing NKT cell development and function. ITIM-containing Ly49 family receptors expressed by NKT cells are proposed to play a role in their development and function. We have produced mice transgenic for the ITAM-associated Ly49D and ITIM-containing Ly49A receptors and their common ligand H2-Dd to determine the importance of these signaling interplays in NKT cell development. Ly49D/H2-Dd transgenic mice had selectively and severely reduced numbers of thymic and peripheral NKT cells, whereas both ligand and Ly49D transgenics had normal numbers of NKT cells. CD1d tetramer staining revealed a blockade of NKT cell development at an early precursor stage. Coexpression of a Ly49A transgene partially rescued NKT cell development in Ly49D/H2-Dd transgenics, presumably due to attenuation of ITAM signaling. Thus, Ly49D-induced ITAM signaling is incompatible with the early development of cells expressing semi-invariant CD1d-restricted TCRs and appropriately harmonized ITIM-ITAM signaling is likely to play an important role in the developmental program of NKT cells.
Insights
The ITAM-associated Ly49D receptor disrupts natural killer T (NKT) cell development by blocking early precursor stages. Harmonized ITIM-ITAM signaling, involving receptors like Ly49A, is crucial for normal NKT cell development.
Area of Science:
- Immunology
- Cellular Biology
- Developmental Biology
Background:
- Natural killer T (NKT) cells possess a semi-invariant T cell receptor (TCR) restricted to CD1d.
- NKT cells also express NK cell-associated receptors, including Ly49 family receptors, which may modulate TCR signaling.
- Immunoreceptor tyrosine-based activation motifs (ITAMs) and inhibitory motifs (ITIMs) within these receptors are hypothesized to influence NKT cell development and function.
Purpose of the Study:
- To investigate the role of ITAM and ITIM signaling motifs in NKT cell development.
- To determine the impact of Ly49D (ITAM) and Ly49A (ITIM) receptors and their ligand H2-Dd on NKT cell development.
Main Methods:
- Generation of transgenic mice expressing Ly49D, Ly49A, and H2-Dd.
- Analysis of thymic and peripheral NKT cell populations using flow cytometry and CD1d tetramer staining.
- Assessment of NKT cell development in single and double transgenic mouse models.
Main Results:
- Ly49D/H2-Dd double transgenic mice exhibited a severe reduction in both thymic and peripheral NKT cells.
- CD1d tetramer staining indicated a developmental blockade at an early NKT cell precursor stage in these mice.
- Coexpression of Ly49A partially rescued NKT cell development, suggesting attenuation of ITAM signaling.
Conclusions:
- Ly49D-mediated ITAM signaling is detrimental to the early development of CD1d-restricted NKT cells.
- Balanced ITIM-ITAM signaling is essential for the proper developmental program of NKT cells.
