title: Antigen-specific lymphocyte proliferative responses in vaccinated and Hypoderma lineatum-infested calves.
abstract: Cattle infested with the common cattle grub, Hypoderma lineatum (Villers) develop specific humoral antibodies and a cellular immune reaction, defined by delayed-type hypersensitivity, to purified H. lineatum proteins. This investigation was designed to study the antigen-specific bovine lymphocyte response to hypodermin A (HyA), a serine protease of larval first-instar H. lineatum. Calves were vaccinated with either native or denatured HyA, and challenge-infested with H. lineatum. The kinetic development of a cellular immune response to HyA was monitored during vaccination and infestation. The HyA-specific responses were highly variable and weak during vaccination and infestation. Although HyA-specific lymphocyte blastogenic responses were observed, no correlation was noted between the magnitude of antigen-specific, peripheral lymphocyte proliferation and larval mortality. In striking contrast to responses observed during infestation, intense HyA-specific lymphocyte responses were observed with 3 calves 6 months after recovery from infestation. In addition, those responses were further heightened by a 250 micrograms booster injection of pure HyA.
authors.affiliation: Knipling Bushland US Livestock Insects Research Laboratory, US Department of Agriculture, Kerrville, TX 79028-0232.
authors.forename: W F
authors.initials: WF
authors.lastname: Fisher
authors.forename: J H
authors.initials: JH
authors.lastname: Pruett
authors.forename: V M
authors.initials: VM
authors.lastname: Howard
authors.forename: P J
authors.initials: PJ
authors.lastname: Scholl
mesh_terms: D000818:Animals; D000917:Antibody Formation; D002417:Cattle; D002418:Cattle Diseases / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D007000:Hypodermyiasis / Q000276:immunology / Q000662:veterinary*; D007111:Immunity, Cellular; D007700:Kinetics; D008213:Lymphocyte Activation; D012697:Serine Endopeptidases / Q000276:immunology*; D014611:Vaccination / Q000662:veterinary*
chemical_list: D012697:Serine Endopeptidases; C030092:hypodermin