title: Mycoplasma synoviae lipoprotein MSPB, the N-terminal part of VlhA haemagglutinin, induces secretion of nitric oxide, IL-6 and IL-1beta in chicken macrophages.
abstract: Mycoplasma synoviae is a major pathogen of chickens and turkeys, causing respiratory disease and infectious synovitis. M. synoviae haemagglutinin VlhA is an abundant surface-exposed lipoprotein and immunodominant antigen. Post-translational cleavage of VlhA generates two proteins, MSPB and MSPA. MSPB, the amino-terminal end of VlhA, is a lipoprotein of about 40-50 kDa but can appear in truncated forms (tMSPB) of about 20-30 kDa. The aim of this study was to determine whether MSPB and tMSPB can stimulate chicken macrophages to secrete NO and cytokines. Macrophages derived from chicken monocytes (MDM) or the MQ-NCSU macrophage cell line were stimulated with M. synoviae protein extracts containing MSPB or tMSPB, as well as with purified MSPB and tMSPB. Proteins from detergent extractions induced IL-6 secretion in MDM and NO secretion in MQ-NCSU. Both MSPB and tMSPB were capable of inducing NO secretion in MQ-NCSU, as well as IL-6 and IL-1beta in MDM. The activity of IL-6 induced by purified tMSPB was similar to the effect of 60 pg/ml of recombinant chicken IL-6. The effect of IL-1beta induced by tMSPB was comparable to the effect of 10 ng/ml of recombinant IL-1beta. Whereas all samples containing MSPB were able to induce NO, IL-6 and IL-1beta, it seemed that the purified tMSPB of about 20 kDa was the most potent in its ability to induce IL-6 and IL-1beta in MDM. Compared to MSPB, tMSPB lacks about 200 amino acids in its carboxyl-terminal part. Therefore, our results suggest that the major part of the stimulating activity is associated with the amino-terminal part of MSPB, most likely with its lipid moiety.
authors.affiliation: Department of Animal Science, University of Ljubljana, Groblje 3, 1230 Domzale, Slovenia.
authors.forename: Miha
authors.initials: M
authors.lastname: Lavric
authors.forename: Dusan
authors.initials: D
authors.lastname: Bencina
authors.forename: Sonja
authors.initials: S
authors.lastname: Kothlow
authors.forename: Bernd
authors.initials: B
authors.lastname: Kaspers
authors.forename: Mojca
authors.initials: M
authors.lastname: Narat
mesh_terms: D000818:Animals; D001426:Bacterial Proteins / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology*; D002645:Chickens / Q000097:blood / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel / Q000662:veterinary; D006388:Hemagglutinins / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology; D053583:Interleukin-1beta / Q000276:immunology / Q000378:metabolism*; D015850:Interleukin-6 / Q000276:immunology / Q000378:metabolism*; D037102:Lectins / Q000737:chemistry / Q000276:immunology / Q000494:pharmacology*; D008264:Macrophages / Q000276:immunology* / Q000378:metabolism / Q000382:microbiology*; D045805:Mycoplasma synoviae / Q000276:immunology*; D009569:Nitric Oxide / Q000276:immunology / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D006388:Hemagglutinins; D053583:Interleukin-1beta; D015850:Interleukin-6; D037102:Lectins; C406455:VlhA protein, Mycoplasma synoviae; D009569:Nitric Oxide