Concanavalin A-stimulated proliferation of T cell subset-depleted lymphocyte populations isolated from Fasciola hepatica-infected cattle.
Over 14 weeks, peripheral blood lymphocytes (PBL) were isolated from eight adult cattle which had been orally infected with Fasciola hepatica via trickle infection over a 10-day period. Two age, breed and sex-matched cattle served as controls. CD4+, CD8+ and gammadelta+ T cells were depleted from whole PBL populations by magnetic bead depletion. Lymphocyte proliferation assays demonstrated a transient, but marked elevation in responsiveness to Concanavalin A (Con A) between weeks 2 and 4 post-infection in PBL from infected animals. Proliferative responses to Con A were significantly greater in PBL from infected cattle than uninfected/control cattle over the initial period of the experiment. Con A-stimulated proliferation of PBL isolated from infected cattle followed a similar pattern to PBL responses to F. hepatica antigen. In both whole and subset-depleted lymphocyte populations from infected cattle, proliferative responses to Con A decreased from day 28 post-infection. Depletion of CD4+, CD8+ and gammadelta+ T cell subpopulations significantly augmented responses soon after infection. These findings suggest that the capacity of bovine PBL to proliferate in response to Con A stimulation, was in some way attenuated by F. hepatica infection and proliferative responses due to non-specific activation was suppressed by the coordinated activities of various lymphocyte subsets.
McCole
D F
DF
Department of Pharmacology, University College Dublin, Ireland.
Doherty
M L
ML
Baird
A W
AW
Davis
W C
WC
McGill
K
K
Torgerson
P R
PR
D000818:Animals; D018414:CD8-Positive T-Lymphocytes; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology*; D002455:Cell Division / Q000187:drug effects; D002478:Cells, Cultured; D003208:Concanavalin A / Q000494:pharmacology*; D005211:Fascioliasis / Q000276:immunology* / Q000662:veterinary*; D008213:Lymphocyte Activation / Q000187:drug effects; D008214:Lymphocytes / Q000166:cytology / Q000187:drug effects*; D016176:T-Lymphocyte Subsets
D003208:Concanavalin A