Cytokine and antibody subclass responses in the intestinal lymph of sheep during repeated experimental infections with the nematode parasite Trichostrongylus colubriformis.
The expression of interleukin (IL)-4, IL-5, IL-10, IL-13, TNF-alpha and IFN-gamma genes, and parasite-specific IgM, IgG1, IgG2, IgA and total IgE levels, were monitored daily in intestinal lymph of sheep infected repeatedly with the nematode parasite Trichostrongylus colubriformis. Host genotype had a significant influence on IL-13 gene activity, with resistant-line (R) sheep consistently expressing higher levels of mRNA than susceptible-line (S) sheep. Mean gene expression of IL-13, IL-4 and IFN-gamma did not differ significantly between the first and second nematode challenge. Field-primed R and S as well as field-primed R and naïve S sheep had lower mean gene expression of IL-5 and IL-10, respectively, during the second when compared to primary challenge. Genes for IL-13 and IL-5 were transiently and strongly up-regulated after nematode infection, particularly in animals with previous exposure to nematodes. Genes for TNF-alpha and IFN-gamma were also transiently up-regulated, but to a lesser extent and more typically after primary challenge. Naïve sheep of both genotypes produced relatively little antibody response after primary challenge. A second nematode challenge resulted in large increases in the lymphatic levels of all antibody sub-classes which were significant for adult antigen-specific IgA and larval antigen-specific IgG1. In naïve S line sheep, the larval-specific IgA and IgG2 response appeared delayed when compared to the R line animals. Field-primed R and S line sheep had relatively high lymphatic IgG1 levels prior to experimental infection and these did not change significantly afterwards. These results demonstrate that during nematode infections, the intestinal micro-environment of sheep is transiently skewed towards Th2 cytokine dominance, although IFN-gamma gene expression continues. This response is accompanied by increases of nematode-specific IgG1, IgA, IgG2 and IgM, as well as of total IgE in lymph plasma.
Pernthaner
Anton
A
AgResearch Limited, Wallaceville Animal Research Centre, Ward Street, Upper Hutt, New Zealand. tony.pernthaner@agresearch.co.nz
Cole
Sally-Ann
SA
Morrison
Lilian
L
Green
Richard
R
Shaw
Richard J
RJ
Hein
Wayne R
WR
D000818:Animals; D000909:Antibodies, Helminth / Q000096:biosynthesis / Q000276:immunology; D016207:Cytokines / Q000235:genetics / Q000276:immunology*; D005243:Feces / Q000469:parasitology; D005786:Gene Expression Regulation / Q000276:immunology; D007132:Immunoglobulin Isotypes / Q000096:biosynthesis / Q000276:immunology; D007411:Intestinal Diseases, Parasitic / Q000235:genetics / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D008196:Lymph / Q000276:immunology / Q000469:parasitology; D008297:Male; D010270:Parasite Egg Count / Q000662:veterinary; D012313:RNA / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012756:Sheep / Q000276:immunology*; D012757:Sheep Diseases / Q000235:genetics / Q000276:immunology* / Q000469:parasitology*; D018709:Statistics, Nonparametric; D014253:Trichostrongylosis / Q000235:genetics / Q000276:immunology / Q000469:parasitology / Q000662:veterinary*; D014254:Trichostrongylus / Q000276:immunology*
D000909:Antibodies, Helminth; D016207:Cytokines; D007132:Immunoglobulin Isotypes; D012313:RNA