The presence of CD8+ invariant NKT cells in mice.
Invariant natural killer T (iNKT) cells develop in the thymus upon recognition of CD1d expressed on developing thymocytes. Although CD4 and CD8 coreceptors are not directly involved in the interaction between CD1d and the T cell receptors (TCRs) of iNKT cells, a conspicuous lack of CD8(+) iNKT cells in mice raised the question of whether CD8(+) iNKT cells are excluded due to negative selection during their thymic development, or if there is no lineage commitment for the development of murine CD8(+) iNKT cells. To address this question, we analyzed iNKT cell-specific TCR V alpha 14(+) transgenic mice, where the V alpha 14 transgene forces the generation of iNKT cells. This allows detailed study of the iNKT cell repertoire. We were able to identify CD8(+) iNKT cells which respond to the NKT cell-specific glycolipid ligand alpha-galactosylceramide. Unlike conventional iNKT cells, CD8(+) iNKT cells produce predominantly IFN-gamma but not IL-4 upon antigen stimulation. We also confirmed the presence of CD8(+) iNKT cells in wild type mice. Our results suggest that CD8(+) NKT cells do exist in mice, although their population size is quite small. Their Th1-skewed phenotype might explain why the population size of this subtype needs to be controlled tightly.
Lee
Hyunji
H
School of Life Sciences and Biotechnology, Korea University, Seoul 136-701, Korea.
Hong
Changwan
C
Shin
Junghoon
J
Oh
Soohwan
S
Jung
Sundo
S
Park
Yoon-Kyung
YK
Hong
Seokmann
S
Lee
Gap Ryol
GR
Park
Se-Ho
SH
D000818:Animals; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D005699:Galactosylceramides / Q000276:immunology; D007371:Interferon-gamma / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D055611:Natural Killer T-Cells / Q000276:immunology* / Q000378:metabolism; D016693:Receptors, Antigen, T-Cell, alpha-beta / Q000235:genetics*; D019076:Transgenes
D005699:Galactosylceramides; D016693:Receptors, Antigen, T-Cell, alpha-beta; C493154:alpha-galactosylceramide; D015847:Interleukin-4; D007371:Interferon-gamma