title: Strain variation in the susceptibility and immune response to Clonorchis sinensis infection in mice.
abstract: Mice have shown various susceptibility to infection by Clonorchis sinensis. To compare the intra-specific variation in the host-parasite relationship of C. sinensis, 6 strains of mice (ICR, BALB/c, C57BL/6, DDY, CBA/N, and C3H/HeN) with 3 different haplotypes were evaluated on their susceptibility. The worm recovery rate and immunological responses were observed after 4 and 8 weeks of infection with 30 metacercariae. The highest worm recovery rate was observed as 20.7% in the C3H/HeN strain after 4 weeks of infection along with histopathological changes. The rate was 10.0% in C57BL/6 mice after 8 weeks. ICR, BALB/c, and CBA/N showed elevated levels of IgE at both time points when compared to the rest of the strains. The serum IgG1 and IgG2a levels were elevated in most of the strains; however, the C57BL/6 strain showed a lower level of IgG2a that indicated the IgG1 predominance over IgG2a. The production of IL-4 after concanavalin-A stimulation of splenocytes slightly increased among the mouse strains except C3H/HeN after 4 or 8 weeks of infection, but each strain produced high levels of IFN-γ after 8 weeks, which implied mixed Th1/Th2 responses. ICR, DDY, CBA/N, and C3H/HeN strains showed a significantly increased level of IL-10 after 8 weeks as compared to C57BL/6. All of the strains showed an increased level of IL-13 and suggested fibrotic changes in the mice. In conclusion, mice are insusceptible to infection with C. sinensis; however, the C57BL/6, BALB/c and ICR strains are relatively susceptible after 8 weeks of infection among the six strains. Worm expulsion may be one of the causes of low susceptibility of C3H/HeN mice strain at the 8th week. Elevated IgE, IFN-γ, and IL-13 of infected mice suggest both Th1 and Th2 responses that may be related to the low host susceptibility.
authors.affiliation: Department of Parasitology and Tropical Medicine, Institute of Endemic Diseases, Seoul National University College of Medicine, Seoul 110-799, Republic of Korea.
authors.forename: Md Hafiz
authors.initials: MH
authors.lastname: Uddin
authors.forename: Shunyu
authors.initials: S
authors.lastname: Li
authors.forename: Young Mee
authors.initials: YM
authors.lastname: Bae
authors.forename: Min-Ho
authors.initials: MH
authors.lastname: Choi
authors.forename: Sung-Tae
authors.initials: ST
authors.lastname: Hong
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood*; D001652:Bile Ducts / Q000469:parasitology / Q000473:pathology*; D002478:Cells, Cultured; D003003:Clonorchiasis / Q000276:immunology* / Q000469:parasitology* / Q000473:pathology; D003004:Clonorchis sinensis / Q000145:classification / Q000254:growth & development / Q000472:pathogenicity; D003208:Concanavalin A / Q000276:immunology; D004195:Disease Models, Animal; D004198:Disease Susceptibility / Q000276:immunology / Q000469:parasitology / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D006239:Haplotypes; D006790:Host-Parasite Interactions; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000096:biosynthesis*; D007378:Interleukins / Q000276:immunology; D008099:Liver / Q000469:parasitology / Q000473:pathology*; D008297:Male; D058488:Metacercariae / Q000254:growth & development / Q000276:immunology / Q000472:pathogenicity; D051379:Mice; D008815:Mice, Inbred Strains; D013045:Species Specificity; D013154:Spleen / Q000166:cytology; D018417:Th1 Cells / Q000276:immunology; D018418:Th2 Cells / Q000276:immunology
chemical_list: D000909:Antibodies, Helminth; D007074:Immunoglobulin G; D007378:Interleukins; D003208:Concanavalin A; D007371:Interferon-gamma