Expression of rearranged TCRgamma genes in natural killer cells suggests a minor thymus-dependent pathway of lineage commitment.
Natural killer (NK) cells are thought to develop from common lymphoid progenitors in the bone marrow. However, immature thymocytes also retain NK potential. Currently, the contribution of the thymus-dependent pathway in normal steady-state NK-cell development is unknown. Here, we show that TCRgamma genes are rearranged in approximately 5% of neonatal and 1% of adult mouse splenic NK cells, and similar levels are detected in NK cells from TCRbeta,delta double-knockout mice, excluding the possibility of T-cell contamination. NK-cell TCRgamma gene rearrangement is thymus dependent because this rearrangement is undetectable in nude mouse NK cells. These results change the current view of NK-cell development and show that a subset of NK cells develops from immature thymocytes that have rearranged TCRgamma genes.
Veinotte
Linnea Lora
LL
Terry Fox Laboratory, British Columbia Cancer Agency, Vancouver, British Columbia, Canada, V5Z 1L3. ftakei@bccrc.ca.
Greenwood
Chelsea Pamela
CP
Mohammadi
Nastaran
N
Parachoniak
Christine Anna
CA
Takei
Fumio
F
D000818:Animals; D017931:DNA Primers; D005786:Gene Expression Regulation / Q000276:immunology; D015321:Gene Rearrangement; D019674:Genes, T-Cell Receptor beta; D019675:Genes, T-Cell Receptor gamma; D007694:Killer Cells, Natural / Q000276:immunology*; D016131:Lymphocyte Subsets / Q000276:immunology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D020411:Oligonucleotide Array Sequence Analysis; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013950:Thymus Gland / Q000276:immunology*
D017931:DNA Primers