Interleukin-7 expression during mouse thymus development.
We have monitored the expression of interleukin-7 (IL-7) in the developing embryonic mouse thymus by a combination of quantitative polymerase chain reaction (PCR) and immunofluorescence microscopy. A strong specific signal for IL-7 mRNA was detected by day 12 in the developing fetal thymus. IL-7 mRNA was found to be maximally expressed on day 15, and then decreased over the next 5 days. Immunofluorescence staining of fetal thymus sections using an anti-IL-7 antibody confirmed these PCR data. IL-7 protein expression was first detected at day 13 of development. At 14 days the intensity of the staining increased by a factor of three and stayed at this level over the next 4 days. The same anti-IL-7 antibody used for immunofluorescence, blocked the proliferation of fetal thymocytes in organotypic cultures. In addition, we detected mRNA coding for IL-2 and SCF (also known as the steel factor or KL) in embryonic thymocytes. The implications of these findings for early thymocyte growth are discussed.
Basel Institute for Immunology, Switzerland.
M V
MV
Wiles
P
P
Ruiz
B A
BA
Imhof
D000818:Animals; D001483:Base Sequence; D015820:Cadherins / Q000235:genetics; D005455:Fluorescent Antibody Technique; D015870:Gene Expression; D016298:Hematopoietic Cell Growth Factors / Q000235:genetics; D007376:Interleukin-2 / Q000235:genetics; D015851:Interleukin-7 / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D009838:Oligodeoxyribonucleotides / Q000737:chemistry; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000235:genetics; D019089:Stem Cell Factor; D013950:Thymus Gland / Q000196:embryology*
D015820:Cadherins; D016298:Hematopoietic Cell Growth Factors; D007376:Interleukin-2; D015851:Interleukin-7; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D019089:Stem Cell Factor