Ly49E expression points toward overlapping, but distinct, natural killer (NK) cell differentiation kinetics and potential of fetal versus adult lymphoid progenitors.
Using a new antibody, we found previously that contrary to adult natural killer (NK) cells, fetal NK cells have a unique phenotype, as they exclusively express Ly49E. This can be explained by an intrinsic different NK differentiation potential of fetal versus adult lymphoid progenitors, by immaturity of fetal NK cells or by instability of Ly49E expression. Here, we show that adult progenitor cells were still capable of differentiating into Ly49E-expressing NK cells but at a much lower frequency. Surprisingly, Ly49E expression in vitro did not require stromal cells. Kinetic analysis in vivo showed that Ly49E was expressed early, together with CD94/NKG2 and Ly49G2, followed by Ly49C, and finally Ly49D. Transfer of sorted Ly49E-positive fetal NK cells showed stable Ly49E expression, and later, part of these cells up-regulated other Ly49 members. These data indicate that although there are intrinsic differences, there is no strict fetal and adult wave of NK cell differentiation.
Stevenaert
Frederik
F
Department of Clinical Chemistry, Microbiology and Immunology, University of Ghent, University Hospital, Belgium.
Van Beneden
Katrien
K
De Creus
An
A
Debacker
Veronique
V
Plum
Jean
J
Leclercq
Georges
G
D000367:Age Factors; D000818:Animals; D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D000950:Antigens, Ly / Q000235:genetics / Q000378:metabolism*; D002454:Cell Differentiation; D002455:Cell Division; D002478:Cells, Cultured; D004268:DNA-Binding Proteins / Q000235:genetics; D005333:Fetus / Q000166:cytology / Q000276:immunology*; D006412:Hematopoietic Stem Cells / Q000276:immunology; D007694:Killer Cells, Natural / Q000145:classification / Q000166:cytology / Q000276:immunology*; D007700:Kinetics; D037181:Lectins, C-Type / Q000235:genetics / Q000378:metabolism; D008099:Liver / Q000166:cytology / Q000196:embryology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D055650:NK Cell Lectin-Like Receptor Subfamily A; D051920:NK Cell Lectin-Like Receptor Subfamily D; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism; D055630:Receptors, NK Cell Lectin-Like; D055607:Receptors, Natural Killer Cell; D013234:Stem Cells / Q000276:immunology*; D014158:Transcription, Genetic
D015703:Antigens, CD; D000950:Antigens, Ly; D004268:DNA-Binding Proteins; C527091:Klra3 protein, mouse; C527092:Klra4 protein, mouse; C527093:Klra5 protein, mouse; C497870:Klrd1 protein, mouse; D037181:Lectins, C-Type; D055650:NK Cell Lectin-Like Receptor Subfamily A; D051920:NK Cell Lectin-Like Receptor Subfamily D; C499308:Rag2 protein, mouse; D011971:Receptors, Immunologic; D055630:Receptors, NK Cell Lectin-Like; D055607:Receptors, Natural Killer Cell; C064655:V(D)J recombination activating protein 2