Inducible and constitutive MHC class II gene expression. Distinct tissue-specific genetic controls
| Autor: | Silvia Sartoris, Mt, Scupoli, Scarpellino L, Paiola F, Jotterand-Bellomo M, Tridente G, Rs, Accolla |
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| Rok vydání: | 1990 |
| Předmět: |
B-Lymphocytes
Macrophages Histocompatibility Antigens Class I Immunology Histocompatibility Antigens Class II Hybrid Cells In Vitro Techniques Blotting Northern Flow Cytometry MHC class II gene regulation somatic cell hybrids B and myeloid cell lineages Major Histocompatibility Complex Mice Gene Expression Regulation Karyotyping somatic cell hybrids MHC class II Animals Humans Immunology and Allergy RNA Messenger gene regulation B and myeloid cell lineages |
| Zdroj: | Università degli Studi di Verona-IRIS Scopus-Elsevier Europe PubMed Central |
| ISSN: | 1550-6606 0022-1767 |
| DOI: | 10.4049/jimmunol.145.6.1960 |
| Popis: | B cells express MHC class II Ag in a constitutive fashion, whereas macrophages can do so only after induction by a variety of exogenous stimuli. In this study we describe interspecies somatic cell hybrids between the human B cell Raji and the murine macrophage cell P388 D1. This murine cell line does not express detectable levels of class II mRNA. Phenotypic, molecular, and karyotype analysis of a series of hybrids showed that murine macrophage class II genes can be expressed in a constitutive fashion under the control of the human B cell genome. This event is the consequence of de novo accumulation of class II specific mRNA and thus probably reflects activation of transcription. In certain cases the amount of murine class II Ag expressed on the surface of the hybrid cell was significantly higher than the one observed in the parental macrophage cells after induction with IFN-gamma and was not further modified by treatment with the murine lymphokine. Reversion from a murine class II-positive to class II-negative cell surface phenotype in the hybrids correlated with reduced expression of human markers and more important with segregation of human chromosomes. Interestingly, in this case certain hybrids still expressed detectable levels of murine class II mRNA and increased levels of murine invariant chain mRNA when compared with parental P388 D1 murine macrophage cells. These results indicate that constitutive class II gene expression behaves as a dominant trait in B cell x macrophage somatic cell hybrids. Possible mechanisms responsible of the different control of class II gene expression during cell type differentiation are discussed. |
| Databáze: | OpenAIRE |
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