title: Interleukin-7 production by B lymphocytes affects the T cell-dependent osteoclast formation in an in vitro model derived from human periodontitis patients.
abstract: Periodontitis is characterized by irreversible destruction of alveolar bone and connective tissue attachment in the periodontium. We recently reported that T cells support the osteoclastogenesis by the overproduction of nuclear factor-kappa-B-ligand (RANKL) and Tumor Necrosis Factor-alpha (TNF-alpha) in an in vitro osteoclastogenesis model from periodontitis patients (Pp). It is known that IL-7 stimulates the production of osteoclastogenic factors by T cells and IL-6 potentiates IL-7 expression. Thus, we studied the involvement of IL-6 and IL-7 in the T cell regulation of osteoclast (OC) formation, in an in vitro osteoclastogenesis model from Pp. We demonstrated high levels of IL-7 in both the media collected from PBMC cultures of Pp and the sera of the same patients. We also demonstrated that freshly isolated B cells from PBMCs of Pp were the source of IL-7 in our model. B cells, in fact, overexpressed IL-7 at mRNA and protein levels, and this production was up-regulated by IL-6. Moreover, the OC formation decreased in the presence of anti-IL-6 and IL-7 functional antibodies in PBMC cultures from Pp. These data suggest that B cells could be responsible for the T cell-dependent osteoclastogenesis in periodontitis through the involvement of IL-6 and IL-7.
authors.affiliation: Department of Human Anatomy and Histology, University of Bari, Bari, Italy.
authors.forename: S
authors.initials: S
authors.lastname: Colucci
authors.forename: G
authors.initials: G
authors.lastname: Mori
authors.forename: G
authors.initials: G
authors.lastname: Brunetti
authors.forename: M
authors.initials: M
authors.lastname: Coricciati
authors.forename: P
authors.initials: P
authors.lastname: Pignataro
authors.forename: A
authors.initials: A
authors.lastname: Oranger
authors.forename: N
authors.initials: N
authors.lastname: Cirulli
authors.forename: F
authors.initials: F
authors.lastname: Mastrangelo
authors.forename: F R
authors.initials: FR
authors.lastname: Grassi
authors.forename: M
authors.initials: M
authors.lastname: Grano
mesh_terms: D000328:Adult; D000368:Aged; D001402:B-Lymphocytes / Q000276:immunology*; D002478:Cells, Cultured; D005260:Female; D006801:Humans; D015850:Interleukin-6 / Q000494:pharmacology; D015851:Interleukin-7 / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D010010:Osteoclasts / Q000502:physiology*; D010518:Periodontitis / Q000276:immunology*
chemical_list: D015850:Interleukin-6; D015851:Interleukin-7