title: [Ageing down-modulates the immune responses to Schistosoma japonicum infection in mice].
abstract: OBJECTIVE
  To investigate the effect of ageing on the immune responses against Schistosoma japonicum infection in mice.
  
  
  METHODS
  Female BALB/c mice were divided into young group (2 months) and old group (18 months), each composed of 8 mice. Each mouse was percutaneously infected with 40 +/- 1 S. japonicum cercariae. At 6 weeks post-infection, the mice were sacrificed, and the spleens were removed and single-cell suspensions of splenocytes were prepared. Worms were perfused from hepatic portal system and counted. The number of eggs in the liver was determined after KOH digestion. Mean single-egg granulomas sizes were determined in stained histological sections. Splenocyte proliferation responses were analyzed by MTT colorimetry. Level of interferon-gamma (IFN-gamma) and interleukin-4 (IL-4) in the splenocyte culture supernatants was determined by ELISA.
  
  
  RESULTS
  The worm burden and egg per gram of liver in old mice [19.75 +/- 1.95, (1.59 +/- 1.05) x 10(4)] were significantly lower than that of young mice [26.00 +/- 2.42, (208 +/- 0.87) x 10(4)] (P < 0.05). The mean volume of single-egg granulomas of the livers in old mice [(30.13 +/- 10.97) x 10(3) mm3] was significantly lower than that of the young mice [(47.02 +/- 24.13) x l0(3) mm3] (P < 0.05).
  
  
  RESULTS
  of T cell proliferation showed that the splenocytes had poorer immune reactivity to ConA in old mice (SI: 1.08 +/- 0.12) than that in young mice (SI: 131 +/- 0.14) (P < 0.05). Levels of IFN-gamma and IL-4 in the splenocyte culture supernatants [(24.05 +/- 6.24), (4.15 +/- 0.68) pg/ml] from old mice were lower than that of young mice [(34.25 +/- 869), (7125 +/- 0.83) pg/ml](P < 0.05).
  
  
  CONCLUSIONS
  Ageing down-modulates the immune responses and the poorer immune reactivity might decrease pathological alterations in mice infected with Schistosoma japonicum.
authors.affiliation: Second Clinical School, Tongi Medical College, Huarzhong University of Science and Technology, Wuhan 430030, China.
authors.forename: Yun-fan
authors.initials: YF
authors.lastname: Yang
authors.forename: Qian
authors.initials: Q
authors.lastname: Sun
authors.forename: Bin-tao
authors.initials: BT
authors.lastname: Su
authors.forename: Lin
authors.initials: L
authors.lastname: Lin
authors.forename: Man-jun
authors.initials: MJ
authors.lastname: Li
authors.forename: Lin
authors.initials: L
authors.lastname: Chen
authors.forename: Hong
authors.initials: H
authors.lastname: Xu
authors.forename: Jia-hui
authors.initials: JH
authors.lastname: Lei
authors.forename: Wen-qi
authors.initials: WQ
authors.lastname: Liu
authors.forename: Yong-long
authors.initials: YL
authors.lastname: Li
mesh_terms: D000375:Aging / Q000276:immunology*; D000818:Animals; D005260:Female; D007371:Interferon-gamma / Q000276:immunology; D015847:Interleukin-4 / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D059208:Parasite Load; D012549:Schistosoma japonicum / Q000276:immunology / Q000472:pathogenicity; D012554:Schistosomiasis japonica / Q000276:immunology* / Q000473:pathology*; D013154:Spleen / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology
chemical_list: D015847:Interleukin-4; D007371:Interferon-gamma