Constitutive Expression of Alpha Interferon by Skin Dendritic Cells Confers Resistance to Infection by Foot-and-Mouth Disease Virus

ABSTRACT The role of dendritic cells (DC) in the initiation of immune responses against foot-and-mouth disease virus (FMDV) is poorly understood. We analyzed the innate response of freshly isolated swine skin DC to the virus and show a rapid induction of beta interferon (IFN-β) mRNA but not IFN-α mRNA. However, these DC secreted both IFN-α and IFN-β proteins in response to live virus but not killed virus. Furthermore, the surface expression of swine major histocompatibility complex class II (SLA II) or CD80/CD86 molecules and antigen processing functions were not affected by FMDV exposure. Given the demonstrated sensitivity of FMDV to IFN-α/β, there was no productive or nonproductive infection of these cells. Finally, freshly isolated skin DC constitutively expressed intracellular IFN-α protein in the absence of stimulation, with no detectable secretion of the cytokine until virus exposure. In situ analysis of these DC showed that these cells express and store IFN-α in uninfected animals. This is the first demonstration of the constitutive expression of IFN-α in resident, tissue-derived DC and indicates that skin DC can play an important role in the innate immune response of swine to viral infections.

Download Full-text

Identifying the role of complement receptor 2 (CR2) on follicular dendritic cells (FDCs) in the persistence of foot and mouth disease virus (FMDV)

Access Microbiology ◽

10.1099/acmi.ac2019.po0074 ◽

2019 ◽

Vol 1 (1A) ◽

Author(s):

Lucy Gordon ◽

Neil Mabbott ◽

Bryan Charleston ◽

Eva Perez

Keyword(s):

Dendritic Cells ◽

Disease Virus ◽

Foot And Mouth Disease ◽

Mouth Disease ◽

Complement Receptor ◽

Follicular Dendritic Cells ◽

Complement Receptor 2 ◽

Mouth Disease Virus ◽

Foot And Mouth

Download Full-text

Detection of Foot-and-Mouth Disease Virus in Swine Meat Juice

Pathogens ◽

10.3390/pathogens9060424 ◽

2020 ◽

Vol 9 (6) ◽

pp. 424

Author(s):

Sean Yeo ◽

Ming Yang ◽

Martin Nyachoti ◽

Rolf Rauh ◽

Johnny D. Callahan ◽

...

Keyword(s):

Disease Virus ◽

Foot And Mouth Disease ◽

Mouth Disease ◽

Sample Type ◽

Financial Loss ◽

Live Virus ◽

Meat Juice ◽

Mouth Disease Virus ◽

Foot And Mouth ◽

Polymerase Chain

Foot-and-mouth disease virus (FMDV) is a highly contagious agent that impacts livestock industries worldwide, leading to significant financial loss. Its impact can be avoided or minimized if the virus is detected early. FMDV detection relies on vesicular fluid, epithelial tags, swabs, serum, and other sample types from live animals. These samples might not always be available, necessitating the use of alternative sample types. Meat juice (MJ), collected after freeze-thaw cycles of skeletal muscle, is a potential sample type for FMDV detection, especially when meat is illegally imported. We have performed experiments to evaluate the suitability of MJ for FMDV detection. MJ was collected from pigs that were experimentally infected with FMDV. Ribonucleic acid (RNA) was extracted from MJ, sera, oral swabs, and lymph nodes from the same animals and tested for FMDV by real-time reverse transcription polymerase chain reaction (rRT-PCR). MJ was also tested for FMDV antigen by Lateral Flow Immunoassay (LFI). FMDV RNA was detected in MJ by rRT-PCR starting at one day post infection (DPI) and as late as 21 DPI. In contrast, FMDV RNA was detected in sera at 1–7 DPI. Antigen was also detected in MJ at 1–9 DPI by LFI. Live virus was not isolated directly from MJ, but was recovered from the viral genome by transfection into susceptible cells. The data show that MJ is a good sample type for FMDV detection.

Download Full-text

Dendritic Cell Internalization of Foot-and-Mouth Disease Virus: Influence of Heparan Sulfate Binding on Virus Uptake and Induction of the Immune Response

Journal of Virology ◽

10.1128/jvi.00021-08 ◽

2008 ◽

Vol 82 (13) ◽

pp. 6379-6394 ◽

Cited By ~ 19

Author(s):

Lisa J. Harwood ◽

Heidi Gerber ◽

Francisco Sobrino ◽

Artur Summerfield ◽

Kenneth C. McCullough

Keyword(s):

Heparan Sulfate ◽

Disease Virus ◽

Binding Capacity ◽

Foot And Mouth Disease ◽

Virus Production ◽

Vaccine Virus ◽

Mouth Disease ◽

Live Virus ◽

Mouth Disease Virus ◽

Foot And Mouth

ABSTRACT Dendritic cells (DC), which are essential for inducing and regulating immune defenses and responses, represent the critical target for vaccines against pathogens such as foot-and-mouth disease virus (FMDV). Although it is clear that FMDV enters epithelial cells via integrins, little is known about FMDV interaction with DC. Accordingly, DC internalization of FMDV antigen was analyzed by comparing vaccine virus dominated by heparan sulfate (HS)-binding variants with FMDV lacking HS-binding capacity. The internalization was most efficient with the HS-binding virus, employing diverse endocytic pathways. Moreover, internalization relied primarily on HS binding. Uptake of non-HS-binding virus by DC was considerably less efficient, so much so that it was often difficult to detect virus interacting with the DC. The HS-binding FMDV replicated in DC, albeit transiently, which was demonstrable by its sensitivity to cycloheximide treatment and the short duration of infectious virus production. There was no evidence that the non-HS-binding virus replicated in the DC. These observations on virus replication may be explained by the activities of viral RNA in the DC. When DC were transfected with infectious RNA, only 1% of the translated viral proteins were detected. Nevertheless, the transfected cells, and DC which had internalized live virus, did present antigen to lymphocytes, inducing an FMDV-specific immunoglobulin G response. These results demonstrate that DC internalization of FMDV is most efficient for vaccine virus with HS-binding capacity, but HS binding is not an exclusive requirement. Both non-HS-binding virus and infectious RNA interacting with DC induce specific immune responses, albeit less efficiently than HS-binding virus.

Download Full-text