Increased frequency of circulating CD19+CD24hiCD38hi B cells with regulatory capacity in patients with Ankylosing spondylitis (AS) naïve for biological agents

• Published in: PloS one 2017, Vol.12 (7), p.e0180726-e0180726
• Main Authors: Bautista-Caro, María-Belén, de Miguel, Eugenio, Peiteado, Diana, Plasencia-Rodríguez, Chamaida, Villalba, Alejandro, Monjo-Henry, Irene, Puig-Kröger, Amaya, Sánchez-Mateos, Paloma, Martín-Mola, Emilio, Miranda-Carús, María-Eugenia
• Format: Article
• Language: English
• Subjects: ADP-ribosyl Cyclase 1 - immunology; Adult; Age; Ankylosing spondylitis; Antibodies; Antigens, CD19 - immunology; Arthritis; B-Lymphocytes - immunology; Biological Factors - therapeutic use; Biology and Life Sciences; Blood; CD19 antigen; CD24 Antigen - immunology; CD3 antigen; CD38 antigen; CD4 antigen; Cell culture; Cytokines; Cytometry; Depletion; Drugs; Enzyme-linked immunosorbent assay; Female; Genotype & phenotype; Humans; Immunoglobulins; In vitro methods and tests; Inflammation; Inflammatory bowel disease; Interferon; Lymphocytes B; Male; Medicine and Health Sciences; Middle Aged; Pathogenesis; Patients; Peripheral blood; Permeability; Research and Analysis Methods; Rheumatology; Spondylitis; Spondylitis, Ankylosing - drug therapy; Spondylitis, Ankylosing - immunology; T cell receptors; TNF inhibitors; Tumor necrosis factor; Tumor necrosis factor-TNF
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0180726

Our objective was to study the frequency of circulating CD19+CD24hiCD38hi B cells (Breg) in AS patients. To this end, peripheral blood was drawn from AS patients naïve for TNF blockers (AS/nb) (n = 42) and healthy controls (HC) (n = 42). Six patients donated blood for a second time, 6 months after initiating treatment with anti-TNFα drugs. After isolation by Ficoll-Hypaque, PBMCs were stained with antibodies to CD3, CD4, CD19, CD24, and CD38, and examined by cytometry. For functional studies, total CD19+ B cells were isolated from PBMCs of 3 HC by magnetical sorting. Breg-depleted CD19+ B cells were obtained after CD19+CD24hiCD38hi B cells were removed from total CD19+ cells by cytometry. Total CD19+ B cells or Breg-depleted CD19+ B cells were established in culture and stimulated through their BCR. Secretion of IFNγ was determined by ELISA in culture supernatants. When compared with HC, AS/nb patients demonstrated a significantly increased frequency of Breg cells, which was independent of disease activity. Anti-TNFα drugs induced a significant reduction of circulating Breg numbers, which were no longer elevated after six months of treatment. Functional in vitro studies showed that the secretion of IFNγ was significantly higher in Breg-depleted as compared with total CD19+ B cells, indicating that Breg can downmodulate B cell pro-inflammatory cytokine secretion. In summary, an increased frequency of circulating CD19+CD24hiCD38hi B cells is observed in AS/nb patients, that is not related with disease activity; anti-TNFα drugs are able to downmodulate circulating Breg numbers in AS.