180 research outputs found
Center for Regional Studies and the Center for Southwest Research fellows presentations 2006: Frank Alvarez, Alicia Romero, Aaron Blecha and Ramona Caplan
No full textFrank Alvarez, Alicia Romero, Aaron Blecha and Ramona Caplan, Center for Southwest Research Graduate Fellows, present on their work at the Center for Southwest Research. Fellow presentatio
Molecular characterization and antiviral analyses of porcine type III interferons
No full textType III interferons (IFNs) are a family of recently identified antiviral cytokines. One to 3 paralogs have been identified in several species; however, little information is available about type III IFNs in pigs. We have identified 2 porcine type III IFNs, Sus scrofa IFN-λ1 (SsIFN-λ1) and SsIFN-λ3, and determined their tissue expression profile and antiviral activities. Open reading frames of SsIFN-λ1 and SsIFN-λ3 are 576 and 588 bp, encoding 191 and 195 amino acid preproteins, respectively. In healthy pigs, SsIFN-λ3 was primarily expressed in mesenteric lymph nodes and intestine, whereas expression of SsIFN-λ1 was found in all tested tissues and was high in mesenteric lymph nodes, intestine, and liver. Porcine cells treated with the viral mimic, dsRNA, robustly increased SsIFN-λ3 expression, with epithelial cells generally displaying the greatest response. Conversely, dsRNA-induced mRNA expressions of SsIFN-λ1, SsIFN-α1, and SsIFN-β were relatively weaker and delayed compared with SsIFN-λ3. SsIFN-λ1 and SsIFN-λ3 peptides exerted similar but lower antiviral potency than SsIFN-α1 and SsIFN-β against a porcine arterivirus and an adenovirus. These findings indicate that pigs have 2 type III IFN paralogs, which have antiviral activity and may serve as targets for modulation of the porcine host–pathogen interaction
Expansion of amphibian intronless interferons revises the paradigm for interferon evolution and functional diversity
No full textCitation: Sang, Y. M., Liu, Q. F., Lee, J., Ma, W. J., McVey, D. S., & Blecha, F. (2016). Expansion of amphibian intronless interferons revises the paradigm for interferon evolution and functional diversity. Scientific Reports, 6, 17. doi:10.1038/srep29072Interferons (IFNs) are key cytokines identified in vertebrates and evolutionary dominance of intronless IFN genes in amniotes is a signature event in IFN evolution. For the first time, we show that the emergence and expansion of intronless IFN genes is evident in amphibians, shown by 24-37 intronless IFN genes in each frog species. Amphibian IFNs represent a molecular complex more complicated than those in other vertebrate species, which revises the established model of IFN evolution to facilitate re-inspection of IFN molecular and functional diversity. We identified these intronless amphibian IFNs and their intron-containing progenitors, and functionally characterized constitutive and inductive expression and antimicrobial roles in infections caused by zoonotic pathogens, such as influenza viruses and Listeria monocytogenes. Amphibians, therefore, may serve as overlooked vectors/hosts for zoonotic pathogens, and the amphibian IFN system provides a model to study IFN evolution in molecular and functional diversity in coping with dramatic environmental changes during terrestrial adaption
Antiviral regulation in porcine monocytic cells at different activation states
No full textMonocytic cells, including macrophages and dendritic cells, exist in different activation states that are critical to the regulation of antimicrobial immunity. Many pandemic viruses are monocytotropic, including porcine reproductive and respiratory syndrome virus (PRRSV), which directly infects subsets of monocytic cells and interferes with antiviral responses. To study antiviral responses in PRRSV-infected monocytic cells, we characterized inflammatory cytokine responses and genome-wide profiled signature genes to investigate response pathways in uninfected and PRRSV-infected monocytic cells at different activation states. Our findings showed suppressed interferon (IFN) production in macrophages in non-antiviral states and an arrest of lipid metabolic pathways in macrophages at antiviral states. Importantly, porcine monocytic cells at different activation states were susceptible to PRRSV and responded differently to viral infection. Based on Gene Ontology (GO) analysis, two approaches were used to potentiate antiviral activity: (i) pharmaceutical modulation of cellular lipid metabolism and (ii) in situ PRRSV replication-competent expression of interferon alpha (IFN-α). Both approaches significantly suppressed exogenous viral infection in monocytic cells. In particular, the engineered IFN-expressing PRRSV strain eliminated exogenous virus infection and sustained cell viability at 4 days postinfection in macrophages. These findings suggest an intricate interaction of viral infection with the activation status of porcine monocytic cells. An understanding and integration of antiviral infection with activation status of monocytic cells may provide a means of potentiating antiviral immunity
Antimicrobial peptides and bacteriocins: alternatives to traditional antibiotics
No full textAntimicrobial peptides (AMPs) are ubiquitous, gene-encoded natural antibiotics that have gained recent attention in the search for new antimicrobials to combat infectious disease. In multicellular organisms, AMPs, such as defensins and cathelicidins, provide a coordinated protective response against infection and are a principal component of innate immunity in vertebrates. In unicellular organisms, AMPs, such as bacteriocins, function to suppress competitor species. Because many AMPs kill bacteria by disruption of membrane integrity and are thus thought to be less likely to induce resistance, AMPs are being extensively evaluated as novel antimicrobial drugs. This review summarizes and discusses the antibiotic properties of AMPs highlighting their potential as alternatives to conventional antibiotics
Cellular immune responses in artificially reared pigs
No full textAn experiment was conducted to determine the influence of artificial rearing on the cellular immune response of young pigs. Artificially reared pigs had lower cellular immune reactivity than sow-reared controls. These results indicate that artificial rearing may result in immunosuppression in young pigs
Effect of feeding streptococcus faecium to artificially reared pigs
No full textTwo trials were conducted with a total of 112 artificially reared pigs to evaluate the effect feeding Streptococcus faecium. The areas studied were growth and feed efficiency, mortality rate, daily scour score, blood parameters (total leukocyte numbers and differentials), and in vivo determination of cell-mediated immunity. The results of the trial indicate that there was no significant advantage to feeding Streptococcus faecium to artificially reared pigs
Molecular evolution of the porcine type I interferon family: subtype-specific expression and antiviral activity
No full textType I interferons (IFNs), key antiviral cytokines, evolve to adapt with ever-changing viral threats during vertebrate speciation. Due to novel pathogenic pressure associated with Suidae speciation and domestication, porcine IFNs evolutionarily engender both molecular and functional diversification, which have not been well addressed in pigs, an important livestock species and animal model for biomedical sciences. Annotation of current swine genome assembly Sscrofa10.2 reveals 57 functional genes and 16 pseudogenes of type I IFNs. Subfamilies of multiple IFNA, IFNW and porcine-specific IFND genes are separated into four clusters with ~60 kb intervals within the IFNB/IFNE bordered region in SSC1, and each cluster contains mingled subtypes of IFNA, IFNW and IFND. Further curation of the 57 functional IFN genes indicates that they include 18 potential artifactual duplicates. We performed phylogenetic construction as well as analyses of gene duplication/conversion and natural selection and showed that porcine type I IFN genes have been undergoing active diversification through both gene duplication and conversion. Extensive analyses of the non-coding sequences proximal to all IFN coding regions identified several genomic repetitive elements significantly associated with different IFN subtypes. Family-wide studies further revealed their molecular diversity with respect to differential expression and restrictive activity on the resurgence of a porcine endogenous retrovirus. Based on predicted 3-D structures of representative animal IFNs and inferred activity, we categorized the general functional propensity underlying the structure-activity relationship. Evidence indicates gene expansion of porcine type I IFNs. Genomic repetitive elements that associated with IFN subtypes may serve as molecular signatures of respective IFN subtypes and genomic mechanisms to mediate IFN gene evolution and expression. In summary, the porcine type I IFN profile has been phylogenetically defined family-wide and linked to diverse expression and antiviral activity, which is important information for further biological studies across the porcine type I IFN family
Interaction between innate immunity and porcine reproductive and respiratory syndrome virus
No full textInnate immunity provides frontline antiviral protection and bridges adaptive immunity against virus infections. However, viruses can evade innate immune surveillance potentially causing chronic infections that may lead to pandemic diseases. Porcine reproductive and respiratory syndrome virus (PRRSV) is an example of an animal virus that has developed diverse mechanisms to evade porcine antiviral immune responses. Two decades after its discovery, PRRSV is still one of the most globally devastating viruses threatening the swine industry. In this review, we discuss the molecular and cellular composition of the mammalian innate antiviral immune system with emphasis on the porcine system. In particular, we focus on the interaction between PRRSV and porcine innate immunity at cellular and molecular levels. Strategies for targeting innate immune components and other host metabolic factors to induce ideal anti-PRRSV protection are also discussed
The effects of levamisole, receiving diets, and pre and post transit potassium on fain and health of stressed calves
No full textWe purchased 264 calves (125 bulls and 139 steers) in Tennessee and
transported them to Kansas to evaluate the effects of levamisole injections and
potassium supplementation, before and after transit, and feedlot receiving rations
on performance and health of stressed calves. The calves were held for 48 to 96
hours in the order-buyer barn, fed either a 1.1% or 1.5% potassium (K) ration,
transported for 24 hours, and fed either a 40% concentrate or hay-plus protein-supplement
receiving diet fortified with either 1.1 or 1.7% K for 28 days. They
were met in Kansas with 16 hr of cold driving rain, followed by severe cold
temperatures, so stress was extreme. Subsequently, the calves grazed native
pasture for 60 days.
Levamisole reduced (P<.10) feedlot mortality. Bulls were castrated upon
arrival and levamisole reduced mortality in castrated bull calves more than in steer
calves (P<.05). Levamisole tended to increase IBR antibody titers and enhance
change in BVD titers. Mortality was 12.3% in calves fed the 40% concentrate diet
and 8.5% in those fed hay and protein supplement. More (P<.10) medical treatments
per calf were required in the concentrate-fed calves than in the hay-fed calves.
Due to the extreme-stress conditions during the first week in the feedlot, the
calves required most of the 28-day receiving period to recover purchase weight
and gains were similar (P>.05) in all groups.
Fewer of the calves fed the 1.5% K pretransit diet died during the first 3
days in the feedlot than of those fed the control diet, but the posttransit K (1.7%
K) diet resulted in a trend toward higher mortality during the receiving period
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