DETECTION OF MICROBES BY NATURAL KILLER T CELLS
Natural killer T (NKT) cells combine features of the innate and adaptive immune systems. For example, they are lymphocytes that express an αβ T cell antigen receptor (TCR), typical of adaptive immunity, but they also express NK receptors, such as NK1.1 (NKR-P1 or CD161c), similar to NK cells, which are part of the innate immune system.1, 2 In mice, the majority of NKT cells express an invariant (i) TCRα chain with Vα14–Jα18 rearrangement.1, 2 We refer to these lymphocytes here as Vα14iNKT cells. These cells have a limited repertoire of TCRβ chains, mainly Vβ8.2, Vβ7, and Vβ2, with the highest representation of Vβ8.2 (more than 50%). Humans have a similar population that mostly expresses an invariant Vα24–Jα18 rearrangement with Vβ11 (Vα24iNKT).1, 2 We refer to these two populations in mice and humans as iNKT cells.
iNKT cells have several unique features. In contrast to conventional T cells that recognize peptide antigens presented by major histocompatibility complex...
KeywordsiNKT Cell Borrelia Burgdorferi Microbial Antigen Lipid Antigen Glycolipid Antigen
This work was supported by NIH grants R37 AI71922, RO1 AI45053, RO1 AI69276 (MK), and a fellowship from The Irvington Institute Fellowship Program of the Cancer Research Institute Research (Y.K.).
- 10.Joyee, A.G. et al. (2007)Distinct NKT cell subsets are induced by different Chlamydia. species leading to differential adaptive immunity and host resistance to the infections J Immunol 178, 1048–1058Google Scholar
- 16.Grubor-Bauk, B., Simmons, A., Mayrhofer, G. Speck, P.G. (2003)Impaired clearance of herpes simplex virus type 1 from mice lacking CD1d or NKT cells expressing the semivariant V alpha 14-J alpha 281 TCR. J Immunol 170, 1430–1434Google Scholar
- 18.Renukaradhya, G.J. et al. (2005)Virus-induced inhibition of CD1d1-mediated antigen presentation: reciprocal regulation by p38 and ERK. J Immunol 175, 4301–4308Google Scholar
- 20.Sanchez, D.J., Gumperz, J.E. Ganem, D. (2005)Regulation of CD1d expression and function by a herpesvirus infection. J Clin Invest 115, 1369–1378Google Scholar
- 24.Nagarajan, N.A. Kronenberg, M. (2007)Invariant NKT cells amplify the innate immune response to lipopolysaccharide. J Immunol 178, 2706–2713Google Scholar
- 28.Mallevaey, T. et al. (2006)Activation of invariant NKT cells by the helminth parasite schistosoma mansoni. J Immunol 176, 2476–2485Google Scholar
- 34.Molano, A. et al. (2000)Cutting edge: the IgG response to the circumsporozoite protein is MHC class II-dependent and CD1d-independent: exploring the role of GPIs in NK T cell activation and antimalarial responses. J Immunol 164, 5005–5009Google Scholar
- 40.Kawahara, K., Kubota, M., Sato, N., Tsuge, K. Seto, Y. (2002)Occurrence of an alpha-galacturonosyl-ceramide in the dioxin-degrading bacterium Sphingomonas wittichii. FEMS Microbiol Lett 214, 289–294Google Scholar
- 44.Kumar, H., Belperron, A., Barthold, S.W. Bockenstedt, L.K. (2000)Cutting edge: CD1d deficiency impairs murine host defense against the spirochete, Borrelia burgdorferi. J Immunol 165, 4797–4801Google Scholar