IL-1 mRNA expression detected by in situ hybridization and polymerase chain reaction in human thymus and thymoma. Correlation with late T-cell maturation in normal versus neoplastic thymus.
Interleukin-1 has long been suggested to participate in the development of T-cells in the thymus. To determine whether IL-1 was produced in the human thymus, we used the technique of in situ hybridization and PCR amplification of mRNA. High levels of IL-1 mRNA were detected in cells at the cortico-medullary border, which separates immature from mature T-cells, suggesting a role for IL-1 in a late stage in T-cell maturation. IL-1 transcripts were detectable by a single step PCR reaction in these samples. We examined a series thymomas (human thymic epithelial tumors) that induce partial T-cell maturation: In this group of thymomas T-cells develop to the cortical stage but not beyond. We failed to detect high levels of IL-1 mRNA expression in these tumors by in-situ hybridization, IL-1 mRNA was detected only in one of these samples by a single step PCR amplification. However, all of the samples were positive, when analyzed with a more sensitive, two step amplification of IL-1 mRNA by the use of nested primers. These results are consistent with the hypothesis that higher level of IL-1 expression is either the consequence of, or required for late T-cell maturation.
Aime
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C
Department of Human Physiology (CNRS URA-D1159), Faculty of Medicine, Paris-Sud, Le Plessis Robinson, France.
Bristol
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L
Cohen-Kaminsky
S
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Berrih-Aknin
S
S
Durum
S
S
Takács
L
L
D000328:Adult; D000368:Aged; D001483:Base Sequence; D002454:Cell Differentiation; D002675:Child, Preschool; D005786:Gene Expression Regulation; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D017403:In Situ Hybridization; D007223:Infant; D007375:Interleukin-1 / Q000096:biosynthesis / Q000235:genetics*; D008875:Middle Aged; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000096:biosynthesis* / Q000235:genetics; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis*; D012334:RNA, Neoplasm / Q000096:biosynthesis*; D013601:T-Lymphocytes / Q000166:cytology*; D013945:Thymoma / Q000378:metabolism*; D013950:Thymus Gland / Q000378:metabolism*; D013953:Thymus Neoplasms / Q000378:metabolism*
D007375:Interleukin-1; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D012334:RNA, Neoplasm