ABSTRACT
RBCs demonstrate immunomodulatory capabilities through the expression of nucleic acid sensors. However, little is known about bat RBCs, and no studies have examined the immune function of bat erythrocytes. In this study, we show that bat RBCs express the nucleic acid-sensing TLRs TLR7 and TLR9 and bind the nucleic acid ligands, ssRNA, and CpG DNA. Collectively, these data suggest that, like human RBCs, bat erythrocytes possess immune function and may be reservoirs for nucleic acids. These findings provide unique insight into bat immunity and may uncover potential mechanisms by which virulent pathogens of humans are concealed in bats.
Subject(s)
Chiroptera , Nucleic Acids , Animals , Chiroptera/genetics , DNA , Erythrocytes , Humans , RNAABSTRACT
Most previous studies of interferon-alpha/beta (IFN-α/ß) response antagonism by alphaviruses have focused upon interruption of IFN-α/ß induction and/or receptor signaling cascades. Infection of mice with Venezuelan equine encephalitis alphavirus (VEEV) or Sindbis virus (SINV) induces serum IFN-α/ß, that elicits a systemic antiviral state in uninfected cells successfully controlling SINV but not VEEV replication. Furthermore, VEEV replication is more resistant than that of SINV to a pre-existing antiviral state in vitro. While host macromolecular shutoff is proposed as a major antagonist of IFN-α/ß induction, the underlying mechanisms of alphavirus resistance to a pre-existing antiviral state are not fully defined, nor is the mechanism for the greater resistance of VEEV. Here, we have separated viral transcription and translation shutoff with multiple alphaviruses, identified the viral proteins that induce each activity, and demonstrated that VEEV nonstructural protein 2-induced translation shutoff is likely a critical factor in enhanced antiviral state resistance of this alphavirus.
Subject(s)
Disease Resistance , Encephalitis Virus, Venezuelan Equine/physiology , Encephalomyelitis, Venezuelan Equine/genetics , Encephalomyelitis, Venezuelan Equine/virology , Host-Pathogen Interactions , Protein Biosynthesis , Viral Nonstructural Proteins/metabolism , Animals , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , Cell Line , Encephalitis Virus, Venezuelan Equine/drug effects , Encephalomyelitis, Venezuelan Equine/metabolism , Encephalomyelitis, Venezuelan Equine/mortality , Horses , Humans , Interferons/biosynthesis , Interferons/pharmacology , Mice , Mutation , Phenotype , RNA, Viral , Viral Nonstructural Proteins/geneticsABSTRACT
The study of large animal embryonic stem cells (ESCs) in vitro has implications for the understanding of lineage differentiation and transgenesis. The first step for ESC derivation is the attachment of the embryo to a substrate on which they can form outgrowths. However, the culture conditions for large animal embryo attachment and ESC derivation have not been studied extensively. Defining culture conditions for embryo attachment such as culture medium and substrate is an important first step for derivation of inner cell mass-derived stem cells. The aim of this study was to compare different types of culture media and substrates for their ability to support attachment of in vitro produced bovine embryos in culture. Bovine embryos were produced in vivo following established protocols. Blastocysts formed on day 8 after fertilization were transferred to 12-well culture plates containing different types of culture media (Dulbecco's Modified Eagle Medium, DMEM or Medium 199, M199) and substrates [bovine fetal fibroblasts, goat fetal fibroblasts, mouse embryonic fibroblasts (STO) or non-cellular substrates (gelatin, laminin, fibronectin)]. Percentage of attached embryos and number of days since fertilization required for attachment were recorded. Bovine blastocysts preferrably attached to feeder cells rather than non-cellular substrates and there was an interact ion of feeder cell type and culture medium used. Therefore, the choice of both feeder cell type and culture medium has to be considered when optimizing conditions to derive cell lines from bovine embryos.(AU)
Subject(s)
Animals , Cattle , In Vitro Techniques/veterinary , Culture Media , Substrates for Biological Treatment , Embryonic Stem Cells , Blastocyst , Feeder CellsABSTRACT
The study of large animal embryonic stem cells (ESCs) in vitro has implications for the understanding of lineage differentiation and transgenesis. The first step for ESC derivation is the attachment of the embryo to a substrate on which they can form outgrowths. However, the culture conditions for large animal embryo attachment and ESC derivation have not been studied extensively. Defining culture conditions for embryo attachment such as culture medium and substrate is an important first step for derivation of inner cell mass-derived stem cells. The aim of this study was to compare different types of culture media and substrates for their ability to support attachment of in vitro produced bovine embryos in culture. Bovine embryos were produced in vivo following established protocols. Blastocysts formed on day 8 after fertilization were transferred to 12-well culture plates containing different types of culture media (Dulbecco's Modified Eagle Medium, DMEM or Medium 199, M199) and substrates [bovine fetal fibroblasts, goat fetal fibroblasts, mouse embryonic fibroblasts (STO) or non-cellular substrates (gelatin, laminin, fibronectin)]. Percentage of attached embryos and number of days since fertilization required for attachment were recorded. Bovine blastocysts preferrably attached to feeder cells rather than non-cellular substrates and there was an interact ion of feeder cell type and culture medium used. Therefore, the choice of both feeder cell type and culture medium has to be considered when optimizing conditions to derive cell lines from bovine embryos.