title: The effect of immunosuppression on protective immunity of turkey poults against infection with turkey coronavirus.
abstract: The objective of the present study was to evaluate the protective effect of humoral and cellular immunities on turkeys infected with turkey coronavirus (TCV). Two trials were conducted with two separate hatches of turkey poults. Turkey's were experimentally immunosuppressed with cyclosporin A (CsA) or cyclophosphamide (CY) and infected with TCV. Prior to infection, treatment with CsA selectively suppressed T cell activity as revealed by 2-3 fold decreased (p < 0.1) lymphocyte proliferation responses to a T cell mitogen, concanavalin A (Con A). Treatment with CY mainly induced B cell deficiency as indicated by significant reductions (p < 0.05) in antibody responses to sheep erythrocytes 7 days after injection. Body weight gain of turkeys treated with CY was significantly lower (p < 0.05) than that of untreated turkeys at 9 days post-infection (PI). Turkeys treated with CY had 1-2 fold higher immunofluorescent antibody assay (IFA) scores for TCV antigens (p < 0.05) in the intestine than untreated turkeys at 9 or 14 days PI. These results suggested that humoral immunity against TCV infection may be important in turkeys.
authors.affiliation: Department of Veterinary Pathobiology, Purdue University, West Lafayette, IN 47907-1175, USA.
authors.forename: Chien Chang
authors.initials: CC
authors.lastname: Loa
authors.forename: Tsang Long
authors.initials: TL
authors.lastname: Lin
authors.forename: Ching Ching
authors.initials: CC
authors.lastname: Wu
authors.forename: Thomas
authors.initials: T
authors.lastname: Bryan
authors.forename: Tom
authors.initials: T
authors.lastname: Hooper
authors.forename: Donna
authors.initials: D
authors.lastname: Schrader
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000096:biosynthesis; D000956:Antigens, Viral / Q000032:analysis; D003208:Concanavalin A / Q000494:pharmacology; D004752:Coronavirus, Turkey / Q000276:immunology*; D003520:Cyclophosphamide / Q000494:pharmacology; D016572:Cyclosporine / Q000494:pharmacology; D004753:Enteritis, Transmissible, of Turkeys / Q000276:immunology*; D005260:Female; D019084:Fluorescent Antibody Technique, Indirect / Q000662:veterinary; D007111:Immunity, Cellular / Q000187:drug effects; D007166:Immunosuppressive Agents / Q000494:pharmacology*; D007422:Intestines / Q000276:immunology; D008213:Lymphocyte Activation; D008214:Lymphocytes / Q000187:drug effects* / Q000276:immunology; D008297:Male; D011897:Random Allocation; D014422:Turkeys
chemical_list: D000914:Antibodies, Viral; D000956:Antigens, Viral; D007166:Immunosuppressive Agents; D003208:Concanavalin A; D016572:Cyclosporine; D003520:Cyclophosphamide