Expression of recombinase-activating genes (RAG-1 and 2) in human decidual mononuclear cells.
Recombinase-activating genes (RAG-1 and RAG-2) are expressed in immature T or B lymphocytes and possess activity to induce V(D)J rearrangement in TCR and Ig genes. We examined their expression in human decidual and non-pregnant endometrial samples using a highly sensitive RT-PCR technique. Expression of RAG-1 and 2 was noted in all (13/13) pregnant decidual tissues obtained at different gestational stages. After anti-human Ig treatment to rule out the possibility of RAG-1,2 expression from decidual B-cells, strong expression of RAGs was still noted in B cell depleted decidual cells in contrast to lymph nodes and PBMC that lost RAG mRNA expression after this treatment. After FACS mediated cell sorting, strong expression of RAG-1,2 was noted in CD16-CD56bright cells and weak expression in CD3+ cells. Although CD16-CD56bright cells lack surface CD3, they express CD3 epsilon mRNA only detectable by RT-PCR. Our results suggest the nature of decidual CD16-CD56bright cells as a progenitor of extrathymic T cells that possess RAG-1 and 2 mRNA as markers of their immaturity, and possibly differentiate into CD3+ extrathymic T-cells in the decidua under the influence of trophoblastic cells. We propose the human decidua as a new site of extrathymic T-cells differentiation and propose possible roles of trophoblastic cells to attract progenitor lymphocytes of bone marrow origin and trigger their TCR rearrangement as thymic epithelial cells.
Department of Obstetrics and Gynaecology, Nihon University School of Medicine, Japan.
S
S
Hayakawa
S
S
Saito
N
N
Nemoto
F
F
Chishima
K
K
Akiyama
H
H
Shiraishi
J
J
Hayakawa
M
M
Karasaki-Suzuki
K T
KT
Fujii
M
M
Ichijo
D000328:Adult; D001483:Base Sequence; D015139:Blotting, Southern; D017252:CD3 Complex / Q000096:biosynthesis; D004268:DNA-Binding Proteins; D003656:Decidua / Q000166:cytology* / Q000276:immunology*; D004717:Endometrium / Q000276:immunology; D005260:Female; D016654:Genes, RAG-1; D005865:Gestational Age; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008297:Male; D008969:Molecular Sequence Data; D009687:Nuclear Proteins; D016133:Polymerase Chain Reaction / Q000379:methods; D011247:Pregnancy; D014176:Protein Biosynthesis; D011506:Proteins / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis
D017252:CD3 Complex; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; D011506:Proteins; C499311:RAG2 protein, human; D012333:RNA, Messenger; C064655:V(D)J recombination activating protein 2