title: Early inflammatory response to the saponin adjuvant Matrix-M in the pig.
abstract: The early inflammatory response to Matrix-M was evaluated in pigs. Adverse reactions measured as body temperature, appetite, activity level and reaction at the site of injection were not observed after s.c. injection with three doses of the adjuvant (75, 100 or 150μg) into one week old piglets. Analyses of the immediate cytokine response of PBMC after in vitro exposure to Matrix-M (AbISCO-100(®)) revealed only a low expression of mRNA for tumour necrosis factor-α (p<0.05) after 6h incubation. Histological examination revealed an infiltration of leukocytes, haemorrhage and necrosis in muscle 24h after i.m. injection of 150μg Matrix-M in pigs aged eleven weeks. At this time, different grades of reactive lymphoid hyperplasia were recorded in the draining lymph node that was enlarged in three of these six pigs injected with Matrix-M. The global transcriptional response at the site of injection and in the draining lymph node was analyzed using Affymetrix GeneChip Porcine Genome Array. A significant enrichment of gene signatures for the cell types described as "myeloid cells" and "plasmacytoid dendritic cells" was observed at the site of injection in Matrix-M injected pigs compared with pigs injected with saline. A number of genes encoding cytokines/chemokines or their receptors were upregulated at the injection site as well as in the draining lymph node. In the draining lymph node, a majority of the upregulated genes were interferon-regulated genes (IRGs). The expression of IFN-β, but not IFN-α, was increased in the draining lymph nodes of a majority of the pigs exposed to Matrix-M. These IFN-β expressing pigs also expressed increased levels of osteopontin (OPN) or stimulator of interferon genes (STING), two factors known to facilitate the expression of type I IFNs in response to viral infection. Thus, Matrix-M does not appear to induce any harmful inflammatory response in piglets whilst contributing to the innate immunity by activating the type I IFN system, possibly through several alternative signalling pathways.
authors.affiliation: Department of Biomedicine and Veterinary Public Health, Section for Immunology, Swedish University of Agricultural Sciences, P.O. Box 588, SE-751 23 Uppsala, Sweden. Electronic address: Caroline.Fossum@slu.se.
authors.forename: Caroline
authors.initials: C
authors.lastname: Fossum
authors.affiliation: Department of Biomedicine and Veterinary Public Health, Section for Immunology, Swedish University of Agricultural Sciences, P.O. Box 588, SE-751 23 Uppsala, Sweden.
authors.forename: Bernt
authors.initials: B
authors.lastname: Hjertner
authors.affiliation: Department of Biomedicine and Veterinary Public Health, Section for Immunology, Swedish University of Agricultural Sciences, P.O. Box 588, SE-751 23 Uppsala, Sweden.
authors.forename: Viktor
authors.initials: V
authors.lastname: Ahlberg
authors.affiliation: Department of Biomedicine and Veterinary Public Health, Section for Immunology, Swedish University of Agricultural Sciences, P.O. Box 588, SE-751 23 Uppsala, Sweden; Research Laboratory for Immunity Enhancement in Humans and Domestic Animals Maejo University, Chiang Mai 50290, Thailand.
authors.forename: Wasin
authors.initials: W
authors.lastname: Charerntantanakul
authors.affiliation: Department of Veterinary Microbiology, University of Saskatchewan, Western College of Veterinary Medicine, Saskatoon, Canada.
authors.forename: Kathy
authors.initials: K
authors.lastname: McIntosh
authors.affiliation: Department of Biomedicine and Veterinary Public Health, Section for Immunology, Swedish University of Agricultural Sciences, P.O. Box 588, SE-751 23 Uppsala, Sweden.
authors.forename: Lisbeth
authors.initials: L
authors.lastname: Fuxler
authors.affiliation: Department of Biomedicine and Veterinary Public Health, Section for Immunology, Swedish University of Agricultural Sciences, P.O. Box 588, SE-751 23 Uppsala, Sweden.
authors.forename: Navisraj
authors.initials: N
authors.lastname: Balagunaseelan
authors.affiliation: National Veterinary Institute, SVA, SE-751 89 Uppsala, Sweden.
authors.forename: Per
authors.initials: P
authors.lastname: Wallgren
authors.affiliation: Isconova AB, Kungsgatan 109, SE-753 18 Uppsala, Sweden.
authors.forename: Karin
authors.initials: K
authors.lastname: Lövgren Bengtsson
mesh_terms: D000276:Adjuvants, Immunologic / Q000008:administration & dosage / Q000494:pharmacology*; D000818:Animals; D000831:Animals, Newborn; D002784:Cholesterol / Q000008:administration & dosage / Q000494:pharmacology*; D016207:Cytokines / Q000235:genetics / Q000276:immunology*; D004338:Drug Combinations; D005786:Gene Expression Regulation / Q000276:immunology*; D007113:Immunity, Innate / Q000276:immunology; D007249:Inflammation / Q000276:immunology / Q000662:veterinary*; D007963:Leukocytes, Mononuclear; D008198:Lymph Nodes / Q000276:immunology; D020411:Oligonucleotide Array Sequence Analysis / Q000662:veterinary; D010743:Phospholipids / Q000008:administration & dosage / Q000494:pharmacology*; D012333:RNA, Messenger / Q000737:chemistry / Q000235:genetics; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000662:veterinary; D012503:Saponins / Q000008:administration & dosage / Q000494:pharmacology*; D013047:Specific Pathogen-Free Organisms; D018709:Statistics, Nonparametric; D013552:Swine; D013553:Swine Diseases / Q000276:immunology*
chemical_list: D000276:Adjuvants, Immunologic; D016207:Cytokines; D004338:Drug Combinations; C493786:ISCOMATRIX; D010743:Phospholipids; D012333:RNA, Messenger; D012503:Saponins; D002784:Cholesterol
keywords: Adjuvant; IRGs; ISCOM; Matrix-M; NETs; Pig; Transcriptional