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Critical Reviews™ in Immunology

ISSN for PRINT: 1040-8401

Institutional price:	$831.00
Issues per year:	6

Best Paper Award Selection - Editorial Board Site

2003, Volume23

93 pages

DOI: 10.1615/CritRevImmunol.v23.i4

Issue price - $132.00

Acquisition of MHC-Specific Receptors on Murine Natural Killer Cells

Linnea L. Veinotte
The Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada

Brian T. Wilhelm
The Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, BC, Canada

Dixie L. Mager
The Terry Fox Laboratory, British Columbia Cancer Agency; and Department of Medical Genetics and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada

Fumio Takei
The Terry Fox Laboratory, British Columbia Cancer Agency; and Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, BC, Canada

ABSTRACT

NK cells in adult mice express two families of MHC class I–specific receptors, namely, Ly49 and CD94/NKG2. Co-expression of these receptors in various combinations generates diverse receptor repertoires. The expression of individual receptors is mostly stochastic and independent of each other. NK cells acquire the receptors as they develop from progenitors in the bone marrow in adult mice. In vivo as well as in vitro studies have shown that the acquisition of the receptors is ordered and regulated by the host MHC class I. Developing NK cells first acquire CD94/NKG2 and subsequently various Ly49 receptors in an ordered manner. Unlike adult NK cells, most fetal and neonatal NK cells express CD94/NKG2 but not Ly49. During the first several weeks after birth, NK cells expressing various Ly49 receptors slowly accumulate, while CD94/NKG2⁺ NK cells decrease to ~50% of the population. The acquisition of NK receptors following hematopoietic stem cell transplantation is also a slow and apparently preprogrammed process, mimicking the ontogeny, regardless of whether stem cells from fetal liver or adult bone marrow are used as donors. The regulation of the transcription of individual receptor genes is rather complex, since two promoters have been identified for the genes encoding Ly49 and CD94.