title: Analysis of mRNA expression for genes associated with regulatory T lymphocytes (CD25, FoxP3, CTLA4, and IDO) after experimental infection with bovine viral diarrhea virus of low or high virulence in beef calves.
abstract: Immunosuppression caused by bovine viral diarrhea virus (BVDV) has been associated with lymphocyte depletion, leukopenia and impairment of leukocyte function; however, no work has been done on the relationship between BVDV and regulatory T lymphocytes (Tregs). The objective of this study was to compare the mRNA expression of genes associated with Tregs (CD25, FoxP3, CTLA4, and IDO), after experimental infection of beef calves with low (LV) or high (HV) virulence BVDV. Thirty BVDV-naïve calves were randomly assigned to three groups. Calves were intra-nasally inoculated with LV (n=10, strain SD-1) or HV (n=10, strain 1373) BVDV or BVDV-free cell culture medium (control, n=10). Quantitative RT-PCR was used to determine the expression of target genes in tracheo-bronchial lymph nodes and spleen on day 5 post-infection. The mRNA expression of CD25 was up-regulated in tracheo-bronchial lymph nodes of LV (P<0.05), but not in HV compared to the control group. The expression of FoxP3 and CTLA4 was not increased in tracheo-bronchial lymph nodes of either of the BVDV-inoculated groups. A dramatic up-regulation of IDO mRNA was observed in tracheo-bronchial lymph nodes of LV (P<0.05), but not HV compared to the control calves. In conclusion, experimental infection with BVDV did not provide evidence of Treg activation based on expression of FoxP3 and CTL4. Differential expression of CD25 and IDO mRNA on day 5 post-infection with HV or LV BVDV might reflect temporal differences in transcription occurring during the immune response elicited by these viral strains, or differences in viral infectivity of the host cells.
authors.affiliation: Department of Population Health, College of Veterinary Medicine, The University of Georgia, Athens, GA, United States. Electronic address: palomnr@uga.edu.
authors.forename: Roberto A
authors.initials: RA
authors.lastname: Palomares
authors.affiliation: Department of Population Health, College of Veterinary Medicine, The University of Georgia, Athens, GA, United States.
authors.forename: David J
authors.initials: DJ
authors.lastname: Hurley
authors.affiliation: Department of Large Animal Medicine, College of Veterinary Medicine, The University of Georgia, Athens, GA, United States.
authors.forename: Amelia R
authors.initials: AR
authors.lastname: Woolums
authors.affiliation: Department of Population Health, College of Veterinary Medicine, The University of Georgia, Athens, GA, United States.
authors.forename: Jacqueline E
authors.initials: JE
authors.lastname: Parrish
authors.affiliation: Department of Pathobiology, College of Veterinary Medicine, Auburn University, Auburn, AL, United States.
authors.forename: Kenny V
authors.initials: KV
authors.lastname: Brock
mesh_terms: D000818:Animals; D001912:Bovine Virus Diarrhea-Mucosal Disease / Q000235:genetics / Q000276:immunology* / Q000473:pathology / Q000821:virology; D060908:CTLA-4 Antigen / Q000235:genetics / Q000276:immunology*; D002417:Cattle; D030241:Diarrhea Virus 1, Bovine Viral / Q000235:genetics / Q000472:pathogenicity; D030242:Diarrhea Virus 2, Bovine Viral / Q000235:genetics / Q000472:pathogenicity; D051858:Forkhead Transcription Factors / Q000235:genetics / Q000276:immunology*; D005786:Gene Expression Regulation; D058507:Host Specificity; D054884:Host-Pathogen Interactions; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase / Q000235:genetics / Q000276:immunology*; D053645:Interleukin-2 Receptor alpha Subunit / Q000235:genetics / Q000276:immunology*; D008297:Male; D012333:RNA, Messenger / Q000235:genetics / Q000276:immunology; D013045:Species Specificity; D013154:Spleen / Q000276:immunology / Q000473:pathology / Q000821:virology; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000473:pathology / Q000821:virology; D014774:Virulence
chemical_list: D060908:CTLA-4 Antigen; D051858:Forkhead Transcription Factors; D050503:Indoleamine-Pyrrole 2,3,-Dioxygenase; D053645:Interleukin-2 Receptor alpha Subunit; D012333:RNA, Messenger
keywords: Bovine viral diarrhea virus; Gene expression; Immunosuppression; Regulatory T lymphocytes