title: [The Effect of Lipopolysaccharide-Induced Mouse B Cell Activation on Schistosoma japonicum Development].
abstract: OBJECTIVE
  To investigate the effect of lipopolysaccharide (LPS)-induced B cell activation on the development of Schistosoma japonicum.
  
  
  METHODS
  Eighteen BALB/c nude mice deficient in T cells and 23 BALB/c SCID mice deficient in T and B cells were used in this study. Each was infected with 30 ± 1 S. japonicum cercariae. The nude (n=9, NL group) and SCID (n=12, SL group) mice then received 2-3 (every two weeks) intraperitoneal injections with LPS (100 μg/mL, 0.2 mL for each mouse). The remaining nude(n=9, N group) and SCID (n=11, S group) mice received PBS injection as control. The mice were sacrificed on days 28 and 36 after infection (n=4/5, 4/5, 5/6, 6/6 for N, NL, S and SL groups, respectively), and adult worms were collected by hepatic portal vein perfusion. The collecting rate of the adult worms was calculated, the body-length measured, and pairs of worms recorded. The liver tissue was collected and digested with 5% KOH, and the number of eggs per gram of liver tissue was calculated. The levels of TGF-β, IFN-γ and IL-10 in peripheral blood were evaluated. Spleen cell suspension was prepared for detecting the proportion of regulatory B cells (Bregs) in splenic lymphocytes.
  
  
  RESULTS
  On day 28 after infection, the body-lengths of male worms in NL and N groups were (7.65±2.85) mm and (5.28±1.64) mm (P<0.01), and those of female worms were (9.64±1.99) mm and (7.49±1.63) mm (P<0.01), respectively. On day 36 after infection, the number of eggs per gram of liver tissue was significantly higher in the NL group than in the N group (1 088±297 vs 715±404, P<0.05), and significantly lower in the SL group than in the S group (217±33 vs 573±160, P<0.01). The proportions of CD(hi)CD5(+)CD19(+) Bregs in N group on days 28 and 36 after infection were (12.73±0.96)% and (37.15±3.04)% (P<0.05), respectively, with no significant difference with that of NL group. The serum levels of TGF-β and IFN-y on day 28 after infection were significantly different between N and NL groups (TGF-β, 101.75±46.72 vs 260.90±45.34 pg/mL; IFN-y, 7.91±1.62 vs 14.11±3.72 pg/mL, both P<0.01). Similarly, significant difference was found for the plasma level of IL-10 on day 36 after infection between the S and N groups (41.85±3.14 vs 66.25±4.16 pg/mL, P<0.01), and between the SL and NL groups (44.48±3.87 vs 72.22±17.76 pg/mL, P<0.01), but not between the LPS groups and the control groups.
  
  
  CONCLUSIONS
  LPS can induce the release of cytokines (e.g. TGF-β) from B cells of mice infected with S. japonium, to facilitate the early development of adult female and male worms.
authors.forename: Hong-bin
authors.initials: HB
authors.lastname: TANG
authors.forename: La-ying
authors.initials: LY
authors.lastname: CHENG
authors.forename: Tao
authors.initials: T
authors.lastname: XIONG
authors.forename: Hui-fen
authors.initials: HF
authors.lastname: DONG
authors.forename: Ming-sen
authors.initials: MS
authors.lastname: JIANG
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000166:cytology / Q000276:immunology*; D016207:Cytokines / Q000097:blood; D005260:Female; D008070:Lipopolysaccharides; D008099:Liver / Q000469:parasitology; D008213:Lymphocyte Activation; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D016513:Mice, SCID; D012549:Schistosoma japonicum; D012554:Schistosomiasis japonica / Q000276:immunology*; D013154:Spleen / Q000166:cytology; D013601:T-Lymphocytes / Q000166:cytology
chemical_list: D016207:Cytokines; D008070:Lipopolysaccharides