Serum Neutralizing and Enhancing Effects on African Swine Fever Virus Infectivity in Adherent Pig PBMC
African swine fever virus (ASFV) causes hemorrhagic fever with mortality rates of up to 100% in domestic pigs. Currently, there are no commercial vaccines for the disease. Only some live-attenuated viruses have been able to protect pigs from ASFV infection. The immune mechanisms involved in the prot...
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| Format: | Article |
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MDPI AG
2022-06-01
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| Series: | Viruses |
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| Online Access: | https://www.mdpi.com/1999-4915/14/6/1249 |
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| author | Jessica A. Canter Theresa Aponte Elizabeth Ramirez-Medina Sarah Pruitt Douglas P. Gladue Manuel V. Borca James J. Zhu |
| author_facet | Jessica A. Canter Theresa Aponte Elizabeth Ramirez-Medina Sarah Pruitt Douglas P. Gladue Manuel V. Borca James J. Zhu |
| author_sort | Jessica A. Canter |
| collection | DOAJ |
| description | African swine fever virus (ASFV) causes hemorrhagic fever with mortality rates of up to 100% in domestic pigs. Currently, there are no commercial vaccines for the disease. Only some live-attenuated viruses have been able to protect pigs from ASFV infection. The immune mechanisms involved in the protection are unclear. Immune sera can neutralize ASFV but incompletely. The mechanisms involved are not fully understood. Currently, there is no standardized protocol for ASFV neutralization assays. In this study, a flow cytometry-based ASFV neutralization assay was developed and tested in pig adherent PBMC using a virulent ASFV containing a fluorescent protein gene as a substrate for neutralization. As with previous studies, the percentage of infected macrophages was approximately five time higher than that of infected monocytes, and nearly all infected cells displayed no staining with anti-CD16 antibodies. Sera from naïve pigs and pigs immunized with a live-attenuated ASFV and fully protected against parental virus were used in the assay. The sera displayed incomplete neutralization with MOI-dependent neutralizing efficacies. Extracellular, but not intracellular, virions suspended in naïve serum were more infectious than those in the culture medium, as reported for some enveloped viruses, suggesting a novel mechanism of ASFV infection in macrophages. Both the intracellular and extracellular virions could not be completely neutralized. |
| first_indexed | 2024-03-09T22:14:32Z |
| format | Article |
| id | doaj.art-a9af231ceec64c0d838189ef3c27140e |
| institution | Directory Open Access Journal |
| issn | 1999-4915 |
| language | English |
| last_indexed | 2024-03-09T22:14:32Z |
| publishDate | 2022-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Viruses |
| spelling | doaj.art-a9af231ceec64c0d838189ef3c27140e2023-11-23T19:26:13ZengMDPI AGViruses1999-49152022-06-01146124910.3390/v14061249Serum Neutralizing and Enhancing Effects on African Swine Fever Virus Infectivity in Adherent Pig PBMCJessica A. Canter0Theresa Aponte1Elizabeth Ramirez-Medina2Sarah Pruitt3Douglas P. Gladue4Manuel V. Borca5James J. Zhu6Foreign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USAForeign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USAForeign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USAForeign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USAForeign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USAForeign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USAForeign Animal Disease Research Unit, Plum Island Animal Disease Center, Agricultural Research Service, United States Department of Agriculture, Orient, NY 11957, USAAfrican swine fever virus (ASFV) causes hemorrhagic fever with mortality rates of up to 100% in domestic pigs. Currently, there are no commercial vaccines for the disease. Only some live-attenuated viruses have been able to protect pigs from ASFV infection. The immune mechanisms involved in the protection are unclear. Immune sera can neutralize ASFV but incompletely. The mechanisms involved are not fully understood. Currently, there is no standardized protocol for ASFV neutralization assays. In this study, a flow cytometry-based ASFV neutralization assay was developed and tested in pig adherent PBMC using a virulent ASFV containing a fluorescent protein gene as a substrate for neutralization. As with previous studies, the percentage of infected macrophages was approximately five time higher than that of infected monocytes, and nearly all infected cells displayed no staining with anti-CD16 antibodies. Sera from naïve pigs and pigs immunized with a live-attenuated ASFV and fully protected against parental virus were used in the assay. The sera displayed incomplete neutralization with MOI-dependent neutralizing efficacies. Extracellular, but not intracellular, virions suspended in naïve serum were more infectious than those in the culture medium, as reported for some enveloped viruses, suggesting a novel mechanism of ASFV infection in macrophages. Both the intracellular and extracellular virions could not be completely neutralized.https://www.mdpi.com/1999-4915/14/6/1249African swine fever virus (ASFV)hyperimmune serumvirus neutralizationflow cytometrymonocyte-derived macrophageextracellular virions |
| spellingShingle | Jessica A. Canter Theresa Aponte Elizabeth Ramirez-Medina Sarah Pruitt Douglas P. Gladue Manuel V. Borca James J. Zhu Serum Neutralizing and Enhancing Effects on African Swine Fever Virus Infectivity in Adherent Pig PBMC Viruses African swine fever virus (ASFV) hyperimmune serum virus neutralization flow cytometry monocyte-derived macrophage extracellular virions |
| title | Serum Neutralizing and Enhancing Effects on African Swine Fever Virus Infectivity in Adherent Pig PBMC |
| title_full | Serum Neutralizing and Enhancing Effects on African Swine Fever Virus Infectivity in Adherent Pig PBMC |
| title_fullStr | Serum Neutralizing and Enhancing Effects on African Swine Fever Virus Infectivity in Adherent Pig PBMC |
| title_full_unstemmed | Serum Neutralizing and Enhancing Effects on African Swine Fever Virus Infectivity in Adherent Pig PBMC |
| title_short | Serum Neutralizing and Enhancing Effects on African Swine Fever Virus Infectivity in Adherent Pig PBMC |
| title_sort | serum neutralizing and enhancing effects on african swine fever virus infectivity in adherent pig pbmc |
| topic | African swine fever virus (ASFV) hyperimmune serum virus neutralization flow cytometry monocyte-derived macrophage extracellular virions |
| url | https://www.mdpi.com/1999-4915/14/6/1249 |
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