title: Global suppression of mitogen-activated ovine peripheral blood mononuclear cells by surface protein activity from Mycoplasma ovipneumoniae.
abstract: Mycoplasma ovipneumoniae is associated with chronic non-progressive pneumonia of sheep and goats. As with many other mycoplasmas involved in animal diseases, protective immune responses have not been achieved with vaccines, even though antibody responses can be obtained. This study focuses on characterizing the interaction of M. ovipneumoniae with ovine PBMC using carboxy-fluorescein-succinimidyl-ester (CFSE) loading and flow cytometry to measure lymphoid cell division. M. ovipneumoniae induced a strong in vitro polyclonal suppression of CD4(+), CD8(+), and B blood lymphocyte subsets. The suppressive activity could be destroyed by heating to 60 degrees C, and partially impaired by formalin and binary ethyleneimine treatment that abolished its viability. The activity resided on the surface-exposed membrane protein fraction of the mycoplasma, since mild trypsin treatment not affecting viability was shown to reduce suppressive activity. Trypsin-treated mycoplasma regained suppressive activity once the mycoplasma was allowed to re-synthesize its surface proteins. Implications for the design of vaccines against M. ovipneumoniae are discussed.
authors.affiliation: Department of Veterinary Microbiology and Preventive Medicine, College of Veterinary Medicine, Iowa State University, VMRI-5, 1802 University Boulevard, Ames, IA 50011, USA.
authors.forename: W
authors.initials: W
authors.lastname: Shahzad
authors.forename: Adebowale Titilayo Phillip
authors.initials: AT
authors.lastname: Ajuwape
authors.forename: Ricardo Francisco
authors.initials: RF
authors.lastname: Rosenbusch
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001426:Bacterial Proteins / Q000276:immunology; D001428:Bacterial Vaccines / Q000276:immunology; D007108:Immune Tolerance; D066298:In Vitro Techniques; D007963:Leukocytes, Mononuclear / Q000276:immunology / Q000382:microbiology; D008213:Lymphocyte Activation; D016131:Lymphocyte Subsets / Q000276:immunology / Q000382:microbiology; D008565:Membrane Proteins / Q000276:immunology; D008934:Mitogens / Q000494:pharmacology; D045802:Mycoplasma ovipneumoniae / Q000276:immunology* / Q000472:pathogenicity*; D011019:Pneumonia, Mycoplasma / Q000276:immunology / Q000382:microbiology / Q000517:prevention & control / Q000662:veterinary*; D012756:Sheep; D012757:Sheep Diseases / Q000276:immunology* / Q000382:microbiology* / Q000517:prevention & control
chemical_list: D000942:Antigens, Bacterial; D000954:Antigens, Surface; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D008565:Membrane Proteins; D008934:Mitogens