title: Changes in macrophage phenotype after infection of pigs with Haemophilus parasuis strains with different levels of virulence.
abstract: Haemophilus parasuis is a colonizer of healthy piglets and the etiological agent of Glässer's disease. Differences in virulence among strains of H. parasuis have been widely observed. In order to explore the host-pathogen interaction, snatch-farrowed colostrum-deprived piglets were intranasally infected with 4 strains of H. parasuis: reference virulent strain Nagasaki, reference nonvirulent strain SW114, field strain IT29205 (from a systemic lesion and virulent in a previous challenge), and field strain F9 (from the nasal cavity of a healthy piglet). At different times after infection, two animals of each group were euthanized and alveolar macrophages were analyzed for the expression of CD163, CD172a, SLA I (swine histocompatibility leukocyte antigen I), SLA II, sialoadhesin (or CD169), and CD14. At 1 day postinfection (dpi), virulent strains induced reduced expression of CD163, SLA II, and CD172a on the surfaces of the macrophages, while nonvirulent strains induced increased expression of CD163, both compared to noninfected controls. At 2 dpi, the pattern switched into a strong expression of CD172a, CD163, and sialoadhesin by the virulent strains, which was followed by a steep increase in interleukin 8 (IL-8) and soluble CD163 in serum at 3 to 4 dpi. The early increase in surface expression of CD163 induced by nonvirulent strains went along with higher levels of IL-8 in serum than those induced by virulent strains in the first 2 days of infection. Alpha interferon (IFN-α) induction was observed only in animals infected with nonvirulent strains. Overall, these results are compatible with a delay in macrophage activation by virulent strains, which may be critical for disease production.
authors.affiliation: Centre de Recerca en Sanitat Animal, UAB-IRTA, Campus de la Universitat Autònoma de Barcelona, Bellaterra, Spain.
authors.forename: Mar
authors.initials: M
authors.lastname: Costa-Hurtado
authors.forename: Alexandre
authors.initials: A
authors.lastname: Olvera
authors.forename: Verónica
authors.initials: V
authors.lastname: Martinez-Moliner
authors.forename: Nuria
authors.initials: N
authors.lastname: Galofré-Milà
authors.forename: Paloma
authors.initials: P
authors.lastname: Martínez
authors.forename: Javier
authors.initials: J
authors.lastname: Dominguez
authors.forename: Virginia
authors.initials: V
authors.lastname: Aragon
mesh_terms: D000818:Animals; D015703:Antigens, CD / Q000097:blood / Q000235:genetics / Q000378:metabolism; D015214:Antigens, Differentiation, Myelomonocytic / Q000097:blood / Q000235:genetics / Q000378:metabolism; D016466:CHO Cells; D048430:Cell Shape; D006224:Cricetinae; D004195:Disease Models, Animal; D006192:Haemophilus Infections / Q000276:immunology* / Q000382:microbiology; D044137:Haemophilus parasuis / Q000276:immunology* / Q000472:pathogenicity; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II / Q000235:genetics / Q000378:metabolism; D054884:Host-Pathogen Interactions; D016898:Interferon-alpha / Q000378:metabolism; D016209:Interleukin-8 / Q000097:blood; D008262:Macrophage Activation; D016676:Macrophages, Alveolar / Q000276:immunology / Q000382:microbiology*; D010641:Phenotype; D011956:Receptors, Cell Surface / Q000097:blood / Q000235:genetics / Q000378:metabolism; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism; D063267:Sialic Acid Binding Ig-like Lectin 1 / Q000235:genetics / Q000378:metabolism; D013552:Swine / Q000276:immunology / Q000382:microbiology; D013553:Swine Diseases / Q000276:immunology* / Q000382:microbiology; D014774:Virulence; D000098902:CD163 Antigen
chemical_list: D015703:Antigens, CD; D015214:Antigens, Differentiation, Myelomonocytic; D000098902:CD163 Antigen; D015395:Histocompatibility Antigens Class I; D000949:Histocompatibility Antigens Class II; D016898:Interferon-alpha; D016209:Interleukin-8; D011956:Receptors, Cell Surface; D011971:Receptors, Immunologic; D063267:Sialic Acid Binding Ig-like Lectin 1; C438668:swine leukocyte antigen