title: Evidence for a trans-acting activator function regulating the expression of the human CD5 antigen.
abstract: Interspecies somatic cell hybrids were generated by fusing the mouse T-lymphoma cell line, BW5147, with normal human T lymphocytes at different stages of differentiation. Thymocytes, activated peripheral T lymphocytes, or an activated T-cell clone were used as human partners, respectively, in three independent fusions. Irrespective of the human cell partner used for fusion, a certain number of hybrids lost CD5 surface expression over a period of time in culture. Analysis at the phenotype and genetic level showed that lack of CD5 expression was due neither to segregation of human autosome 11, on which the CD5 gene has been mapped, nor to deletion of the CD5 structural gene. Furthermore, loss of CD5 surface expression correlated with the absence of specific mRNA. Since these hybrids preferentially segregate human chromosomes, these results indicate the existence of a non-syntenic trans-active locus, or loci, positively controlling the expression of the human CD5 gene.
authors.affiliation: Institute of Immunology and Infectious Diseases, Medical School, University of Verona, Policlinico Borgo Roma, Italy.
authors.forename: M T
authors.initials: MT
authors.lastname: Scupoli
authors.forename: S
authors.initials: S
authors.lastname: Sartoris
authors.forename: M
authors.initials: M
authors.lastname: Nicolis
authors.forename: T
authors.initials: T
authors.lastname: Cestari
authors.forename: C
authors.initials: C
authors.lastname: Cambiaggi
authors.forename: G
authors.initials: G
authors.lastname: Tridente
authors.forename: R S
authors.initials: RS
authors.lastname: Accolla
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000235:genetics*; D018956:CD5 Antigens; D005434:Flow Cytometry; D005786:Gene Expression Regulation; D006801:Humans; D006822:Hybrid Cells; D051381:Rats; D013601:T-Lymphocytes / Q000276:immunology; D015534:Trans-Activators
chemical_list: D015703:Antigens, CD; D018956:CD5 Antigens; D015534:Trans-Activators