title: Increasing the ex vivo antigen-specific IFN-γ production in subpopulations of T cells and NKp46+ cells by anti-CD28, anti-CD49d and recombinant IL-12 costimulation in cattle vaccinated with recombinant proteins from Mycobacterium avium subspecies paratuberculosis.
abstract: T cells, which encounter specific antigen (Ag), require additional signals to mount a functional immune response. Here, we demonstrate activation of signal 2, by anti-CD28 mAb (aCD28) and other costimulatory molecules (aCD49d, aCD5), and signal 3, by recombinant IL-12, enhance Ag-specific IFN-γ secretion by CD4, CD8, γδ T cells and NK cells. Age matched male jersey calves, experimentally infected with Mycobacterium avium subsp. paratuberculosis (MAP), were vaccinated with a cocktail of recombinant MAP proteins or left unvaccinated. Vaccine induced ex vivo recall responses were measured through Ag-specific IFN-γ production by ELISA and flow cytometry. There was a significant increase in production of IFN-γ by T cell subsets or NKp46+ cells cultured in the presence of Ag and aCD28/aCD49d. The increase was accompanied by an increase in the integrated median fluorescence intensity (iMFI) of activated T cells. Addition of rIL-12 induced a significant additive effect leading to a maximum increase in responder frequency of Ag-specific T cell subsets or NKp46+ cells with a heavy bias toward IFN-γ production by CD4 T cells. We provide the first description of using aCD28/aCD49d costimulation to potentiate an Ag-specific increase in the production of IFN-γ in bovine immunology. The study also shows the degree of signaling in T cells is regulated by the costimulatory environment.
authors.affiliation: Section for Immunology and Vaccinology, National Veterinary Institute, Technical University of Denmark, Bülowsvej 27, 1870 Frederiksberg C, Denmark.
authors.forename: Aneesh
authors.initials: A
authors.lastname: Thakur
authors.forename: Ulla
authors.initials: U
authors.lastname: Riber
authors.forename: William C
authors.initials: WC
authors.lastname: Davis
authors.forename: Gregers
authors.initials: G
authors.lastname: Jungersen
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis / Q000276:immunology; D000911:Antibodies, Monoclonal / Q000494:pharmacology; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology* / Q000382:microbiology; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000276:immunology / Q000382:microbiology*; D004797:Enzyme-Linked Immunosorbent Assay / Q000662:veterinary; D005434:Flow Cytometry / Q000662:veterinary; D007371:Interferon-gamma / Q000032:analysis / Q000276:immunology*; D007963:Leukocytes, Mononuclear; D008297:Male; D016927:Mycobacterium avium subsp. paratuberculosis / Q000276:immunology*; D010283:Paratuberculosis / Q000276:immunology* / Q000382:microbiology; D015398:Signal Transduction / Q000276:immunology*; D018709:Statistics, Nonparametric; D014611:Vaccination / Q000662:veterinary
chemical_list: D000907:Antibodies, Bacterial; D000911:Antibodies, Monoclonal; D007371:Interferon-gamma
keywords: Cattle; Costimulation; Flow cytometry; IFN-γ; T cells