title: CD5-positive B cells in healthy elderly humans are a polyclonal B cell population.
abstract: B cell chronic lymphocytic leukemia (B-CLL) is a disease of the elderly and is characterized by a malignant clone of CD5+ B cells. In old mice, clonal expansions of CD5+ B cells are a common feature, and these animals frequently develop B-CLL. To investigate whether clonal expansion of CD5+ B cells also occurs in elderly humans, predisposing for the development of B-CLL, we analyzed VH gene rearrangements of CD5+ B cells from blood samples of four healthy, 65-82-years-old volunteers as markers of clonality. CD5+ and CD5-B cells were obtained by cell sorting, CDRIII of rearranged VH genes were amplified by polymerase chain reaction, and fragment length analysis was performed. All samples demonstrated a polyclonal pattern of VH gene length distribution. In addition, VH gene rearrangements were amplified and sequenced from sorted single cells of two of the donors. No clonally related CD5+ or CD5- B cells were observed. Thus, development of dominant clones of CD5+ peripheral blood B cells is unlikely to be a common trait of elderly individuals.
authors.affiliation: Department of Pathology, University Hospital of the JWG-University Frankfurt, Frankfurt am Main, Germany.
authors.forename: K D
authors.initials: KD
authors.lastname: Geiger
authors.forename: U
authors.initials: U
authors.lastname: Klein
authors.forename: A
authors.initials: A
authors.lastname: Bräuninger
authors.forename: S
authors.initials: S
authors.lastname: Berger
authors.forename: K
authors.initials: K
authors.lastname: Leder
authors.forename: K
authors.initials: K
authors.lastname: Rajewsky
authors.forename: M L
authors.initials: ML
authors.lastname: Hansmann
authors.forename: R
authors.initials: R
authors.lastname: Küppers
mesh_terms: D000375:Aging / Q000235:genetics / Q000276:immunology*; D000818:Animals; D016175:B-Lymphocyte Subsets / Q000737:chemistry / Q000166:cytology*; D018956:CD5 Antigens / Q000032:analysis*; D002999:Clone Cells; D004198:Disease Susceptibility; D015326:Gene Rearrangement, B-Lymphocyte, Heavy Chain; D006801:Humans; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000209:etiology; D051379:Mice; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D013045:Species Specificity
chemical_list: D018956:CD5 Antigens