Related Experiment Videos
Interactions of poult enteritis and mortality syndrome-associated reovirus with various cell types in vitro
C L Heggen-Peay1, M A Cheema, R A Ali
1Department of Poultry Science, College of Agriculture and Life Sciences, North Carolina State University, Raleigh, North Carolina 27695, USA.
Abstract:
An avian reovirus, ARV-CU98, has recently been isolated from poults experiencing poult enteritis and mortality syndrome (PEMS). To further understand ARV-CU98 and its role in PEMS, the current study investigates interactions of ARV-CU98 with various cell types in vitro. When macrophages, B cells, T cells, and liver cells of chicken or turkey origin were co-incubated with ARV-CU98, only cells of liver origin demonstrated cytopathic effects, the presence of viral antigen, and reduced metabolic activity over time. Furthermore, distinctive pockets of viral particles were evident in electron microscopic examination of a chicken hepatocellular carcinoma (LMH) cell line, but not in a chicken macrophage cell line (MQ-NCSU) co-incubated with virus. Additional evidence of viral replication in LMH, cells but not MQ-NCSU cells was demonstrated by the presence of two viral bands (43 and 145 kD size) in cell lysates from LMH cells exposed to ARV-CU98. Although not capable of being infected by ARV-CU98, MQ-NCSU cells do appear to be activated by the virus since IL-1 mRNA expression is increased in MQ-NCSU cells 2 h after addition of the virus. LMH cells exposed to the virus demonstrate a decrease in IL-1 mRNA expression by 8 to 10 h after addition of the virus, perhaps corresponding to the initiation of infection by the virus. In conclusion, this study demonstrates that ARV-CU98 actively infects and replicates in LMH cells, but not in lymphocytes or macrophages, suggesting that the liver may be a target and site of replication of ARV-CU98 in poults experiencing PEMS.
Insights
Avian reovirus ARV-CU98 infects liver cells, not immune cells, in poults with enteritis. This suggests the liver is a key site for ARV-CU98 replication and disease development in poult enteritis and mortality syndrome (PEMS).
Area of Science:
- Veterinary Virology
- Poult Enteritis and Mortality Syndrome (PEMS)
- Avian Pathology
Background:
- Poult enteritis and mortality syndrome (PEMS) causes significant economic losses in the poultry industry.
- Avian reovirus (ARV) is implicated in PEMS, but its cellular targets and replication sites remain unclear.
- Understanding ARV-CU98's cellular interactions is crucial for PEMS pathogenesis research.
Purpose of the Study:
- To investigate the in vitro cellular tropism and replication of avian reovirus ARV-CU98.
- To determine which cell types are susceptible to ARV-CU98 infection and support viral replication.
- To elucidate the early cellular responses of immune and liver cells to ARV-CU98 exposure.
Main Methods:
- Co-incubation of ARV-CU98 with chicken/turkey macrophages, B cells, T cells, and liver cells (LMH cell line).
- Assessment of cytopathic effects, viral antigen presence, metabolic activity, and viral particle localization via electron microscopy.
- Analysis of viral replication through SDS-PAGE of cell lysates and measurement of IL-1 mRNA expression.
Main Results:
- ARV-CU98 induced cytopathic effects, viral antigen presence, and reduced metabolic activity exclusively in liver cells (LMH).
- Electron microscopy confirmed viral particle pockets in LMH cells but not in macrophages (MQ-NCSU).
- Viral replication was evident in LMH cells (43 and 145 kD viral bands) but not MQ-NCSU cells, which showed increased IL-1 mRNA expression, indicating activation.
Conclusions:
- ARV-CU98 actively infects and replicates in liver cells (LMH), but not in lymphocytes or macrophages.
- The liver is identified as a primary target organ and replication site for ARV-CU98 in poults with PEMS.
- While macrophages are not infected, they are activated by ARV-CU98, suggesting complex immune interactions during PEMS.