Related Experiment Videos
Hemagglutination with porcine reproductive and respiratory syndrome virus
1Department of Veterinary Epizootiology, College of Agriculture and Veterinary Medicine, Nihon University, Fujisawa, Japan.
Abstract:
Porcine reproductive and respiratory syndrome (PRRS) virus grown on MARC-145 cell cultures was tested for hemagglutination (HA) with erythrocytes from a variety of species at 4 degrees C, room temperature and 37 degrees C. HA was observed at all temperatures with mouse erythrocytes but not with cattle, sheep, goat, horse, swine, guinea pig, mongolian gerbil, goose and chicken erythrocytes. The HA activity was enhanced by treatment of virus materials with Tween 80 followed by treatment with ether. The HA titer and HA pattern of virus materials treated with Tween 80 and ether (TE) were 4- to 8-fold higher and more clear than those of the virus materials without TE treatment. The optimum conditions consisted in pretreatment of virus material with Tween 80 at a final concentration of 0.06-0.125% (v/ v) for 15-60 min followed by treatment with ether at a concentration of 50% (v/v) for 5-15 min in ice bath with continuous shaking. The curve of active virus production in intra- and extracellular virus samples resembled that of HA production although it rose somewhat earlier in intracellular virus samples. The HA reaction was inhibited by specific antiserum. HI antibody titers of individual pig sera showed a significant positive correlation with their neutralizing antibody titers.
Insights
Porcine reproductive and respiratory syndrome (PRRS) virus shows hemagglutination (HA) with mouse erythrocytes. Treatment with Tween 80 and ether enhances PRRS virus HA activity, aiding diagnostics.
Area of Science:
- Veterinary Virology
- Immunology
Background:
- Porcine reproductive and respiratory syndrome (PRRS) poses significant challenges to swine health and global agriculture.
- Understanding PRRS virus (PRRSv) interactions with host cells and its antigenicity is crucial for developing effective diagnostic tools and vaccines.
Purpose of the Study:
- To investigate the hemagglutination (HA) properties of PRRS virus grown in cell culture.
- To optimize conditions for enhancing PRRS virus HA activity for improved detection and characterization.
- To correlate hemagglutination inhibition (HI) antibody titers with neutralizing antibody titers in pigs.
Main Methods:
- PRRS virus propagated on MARC-145 cells was tested for hemagglutination using erythrocytes from various animal species at different temperatures.
- Virus samples were treated with Tween 80 and ether (TE) to assess enhancement of HA activity.
- Optimal conditions for TE treatment, including reagent concentrations and incubation times, were determined.
- Virus production curves were compared with HA production curves.
- Hemagglutination inhibition (HI) assays were performed using specific antiserum and pig sera.
Main Results:
- PRRS virus exhibited hemagglutination specifically with mouse erythrocytes across tested temperatures (4°C, room temperature, 37°C).
- Treatment with Tween 80 and ether (TE) significantly enhanced HA titer (4- to 8-fold) and clarity of HA patterns.
- Optimized TE treatment involved 0.06-0.125% Tween 80 for 15-60 min, followed by 50% ether for 5-15 min on ice.
- Active virus production curves paralleled HA production curves, with intracellular virus appearing earlier.
- Specific antiserum inhibited the HA reaction, and HI antibody titers correlated positively with neutralizing antibody titers.
Conclusions:
- Mouse erythrocytes are suitable for detecting PRRS virus hemagglutination.
- Tween 80 and ether treatment effectively enhances PRRS virus HA activity, improving its utility in diagnostics.
- The correlation between HI and neutralizing antibodies suggests the potential of HA-based assays for monitoring immune responses to PRRS virus.