title: Cross reactivity of immune responses to porcine reproductive and respiratory syndrome virus infection.
abstract: Because porcine reproductive and respiratory syndrome virus (PRRSV) exhibits extensive genetic variation among field isolates, characterizing the extent of cross reactivity of immune responses, and most importantly cell-mediated immunity (CMI), could help in the development of broadly cross-protective vaccines. We infected 12 PRRSV-naïve pigs with PRRSV strain FL12 and determined the number of interferon (IFN)-γ secreting cells (SC) by ELISpot assay using ten type 2 and one type 1 PRRSV isolates as recall antigens. The number of IFN-γ SC was extremely variable among animals, and with exceptions, late to appear. Cross reactivity of IFN-γ SC among type 2 isolates was broad, and we found no evidence of an association between increased genetic distance among isolates and the intensity of the CMI response. Comparable to IFN-γ SC, total antibodies evaluated by indirect immunofluorescence assay (IFA) were cross reactive, however, neutralizing antibody titers could only be detected against the strain used for infection. Finally, we observed a moderate association between homologous IFN-γ SC and neutralizing antibodies.
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, United States; Nebraska Center for Virology, University of Nebraska-Lincoln, United States.
authors.forename: Ignacio
authors.initials: I
authors.lastname: Correas
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, United States; Nebraska Center for Virology, University of Nebraska-Lincoln, United States.
authors.forename: Fernando A
authors.initials: FA
authors.lastname: Osorio
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, United States.
authors.forename: David
authors.initials: D
authors.lastname: Steffen
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, United States; Nebraska Center for Virology, University of Nebraska-Lincoln, United States.
authors.forename: Asit K
authors.initials: AK
authors.lastname: Pattnaik
authors.affiliation: School of Veterinary Medicine and Biomedical Sciences, University of Nebraska-Lincoln, United States; Nebraska Center for Virology, University of Nebraska-Lincoln, United States. Electronic address: hiepvu@unl.edu.
authors.forename: Hiep L X
authors.initials: HLX
authors.lastname: Vu
mesh_terms: D000818:Animals; D057134:Antibodies, Neutralizing / Q000096:biosynthesis*; D000914:Antibodies, Viral / Q000096:biosynthesis*; D003429:Cross Reactions; D014644:Genetic Variation; D005838:Genotype; D007111:Immunity, Cellular / Q000235:genetics*; D007371:Interferon-gamma / Q000096:biosynthesis / Q000276:immunology; D019318:Porcine Reproductive and Respiratory Syndrome / Q000276:immunology* / Q000821:virology; D019316:Porcine respiratory and reproductive syndrome virus / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000276:immunology*; D013552:Swine; D013601:T-Lymphocytes / Q000276:immunology* / Q000821:virology
chemical_list: D057134:Antibodies, Neutralizing; D000914:Antibodies, Viral; D007371:Interferon-gamma
keywords: Cell-mediated immunity; Heterologous immunity; Interferon-γ; Porcine reproductive and respiratory syndrome virus (PRRSV); T cell cross reactivity