title: The role of B-cells in immunity against adult Strongyloides venezuelensis.
abstract: BACKGROUND
  Strongyloides venezuelensis has been used as a tool and model for strongyloidiasis research. Elimination of S. venezuelensis adult worms from mice has been particularly associated with proliferation and activation of intestinal mast cells and eosinophils. To date, the role of B-cells in the protective mechanism against adult Strongyloides infection in experimental animals has not been reported in the literature. Therefore, the present study was carried to investigate the role of B-lymphocytes in immunity against adult S. venezuelensis infection using mice with a targeted deletion of the JH locus.
  
  
  METHODS
  JHD knockout mice with its wild-type Balb/c mice were infected by intra-duodenal implantation of adult S. venezuelensis. Fecal egg count, intestinal worm recovery, mucosal mast cells and eosinophils were counted.
  
  
  RESULTS
  At day 11 post infection, parasites in wild-type mice stopped egg laying, while in JHD knockout mice parasites continued to excrete eggs until the end of the observation period, day 107. The higher number of parasite eggs expelled in the feces of JHD knockout infected mice was a consequence of higher worm burdens, which established in the small intestine of these animals. On the other hand worm fecundity was comparable in both groups of mice. Both B-cell-deficient mice and wild-type mice, showed an influx of mucosal mast cells and eosinophils. The absolute numbers in JHD knockout mice were lower than those seen in wild-type mice at day 11, but not to a level of significance. JHD knockout mice could not recover from infection despite the recruitment of both types of cells.
  
  
  CONCLUSIONS
  Our findings highlight a role of B cells in mucosal immunity against invasion of adult S. venezuelensis and in its expulsion. Therefore, we conclude that B-cells together with mucosal mast cells and eosinophils, contribute to immunity against adult S. venezuelensis by mechanism(s) to be investigated.
authors.affiliation: Department of Medical Parasitology, Faculty of Medicine, Umm AL-Qura University, Makkah, Kingdom of Saudia Arabia. mmelmalky@uqu.edu.sa
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: El-Malky
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Maruyama
authors.forename: Saeed A
authors.initials: SA
authors.lastname: Al-Harthi
authors.forename: Samar N
authors.initials: SN
authors.lastname: El-Beshbishi
authors.forename: Nobu
authors.initials: N
authors.lastname: Ohta
mesh_terms: D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology*; D004195:Disease Models, Animal; D004804:Eosinophils / Q000276:immunology; D005243:Feces / Q000469:parasitology; D018928:Immunity, Mucosal; D007422:Intestines / Q000469:parasitology; D008297:Male; D008407:Mast Cells / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D010270:Parasite Egg Count; D013321:Strongyloides / Q000276:immunology*; D013322:Strongyloidiasis / Q000276:immunology*