Aberrant DAP12 signaling in the 129 strain of mice: implications for the analysis of gene-targeted mice.
NK cells are implicated in antiviral responses, bone marrow transplantation and tumor immunosurveillance. Their function is controlled, in part, through the Ly49 family of class I binding receptors. Inhibitory Ly49s suppress signaling, while activating Ly49s (i.e., Ly49D) activate NK cells via the DAP12 signaling chain. Activating Ly49 signaling has been studied primarily in C57BL/6 mice, however, 129 substrains are commonly used in gene-targeting experiments. In this study, we show that in contrast to C57BL/6 NK cells, cross-linking of DAP12-coupled receptors in 129/J mice induces phosphorylation of DAP12 but not calcium mobilization or cytokine production. Consistent with poor-activating Ly49 function, 129/J mice reject bone marrow less efficiently than C57BL/6 mice. Sequence analysis of receptors and DAP12 suggests no structural basis for inactivity, and both the 129/J and C57BL/6 receptors demonstrate normal function in a reconstituted receptor system. Most importantly, reconstitution of Ly49D in 129/J NK cells demonstrated that the signaling deficit is within the NK cells themselves. These unexpected findings bring into question any NK analysis of 129/J, 129Sv, or gene-targeted mice derived from these strains before complete backcrossing, and provide a possible explanation for the differences observed in the immune response of 129 mice in a variety of models.
McVicar
Daniel W
DW
Laboratory of Experimental Immunology, National Cancer Institute, Frederick, MD 21702, USA. MCVICAR@NIH.GOV
Winkler-Pickett
Robin
R
Taylor
Lynn S
LS
Makrigiannis
Andrew
A
Bennett
Michael
M
Anderson
Stephen K
SK
Ortaldo
John R
JR
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D000950:Antigens, Ly; D016026:Bone Marrow Transplantation / Q000276:immunology; D016466:CHO Cells; D002460:Cell Line; D006224:Cricetinae; D018390:Gene Targeting; D006084:Graft Rejection / Q000235:genetics / Q000276:immunology; D006801:Humans; D007694:Killer Cells, Natural / Q000276:immunology*; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins / Q000378:metabolism; D008565:Membrane Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D018448:Models, Immunological; D055650:NK Cell Lectin-Like Receptor Subfamily A; D011971:Receptors, Immunologic / Q000172:deficiency / Q000235:genetics* / Q000378:metabolism*; D055630:Receptors, NK Cell Lectin-Like; D015398:Signal Transduction
D048868:Adaptor Proteins, Signal Transducing; D000950:Antigens, Ly; C527092:Klra4 protein, mouse; D037181:Lectins, C-Type; D008562:Membrane Glycoproteins; D008565:Membrane Proteins; D055650:NK Cell Lectin-Like Receptor Subfamily A; D011971:Receptors, Immunologic; D055630:Receptors, NK Cell Lectin-Like; C110546:TYROBP protein, human